PLL Frequency Synthesizer Family MC145151-2 MC145152

MOTOROLA Order this document SEMICONDUCTOR TECHNICAL DATA by MC145151–2/D

MC145151-2 PLL FrequencySynthesizer MC145152-2 Family MC145155-2 CMOS MC145156-2 The devices described in this document are typically used as low–power, MC145157-2 phase–locked loop frequency synthesizers. When combined with an external MC145158-2 low–pass filter and voltage–controlled oscillator, these devices can provide all the remaining functions for a PLL frequency synthesizer operating up to the device’s frequency limit. For higher VCO frequency operation, a down mixer or a prescaler can be used between the VCO and the synthesizer IC. These frequency synthesizer chips can be found in the following and other applications: CATV TV Tuning AM/FM Radios Scanning Receivers Two–Way Radios Amateur Radio

OSC ÷ R

CONTROL LOGIC φ

÷ A ÷ N

÷ P/P + 1 VCO

OUTPUT FREQUENCY CONTENTS Page DEVICE DETAIL SHEETS MC145151–2 Parallel–Input, Single–Modulus ...... 2 MC145152–2 Parallel–Input, Dual–Modulus ...... 5 MC145157–2 Serial–Input, Single–Modulus ...... 9 MC145158–2 Serial–Input, Dual–Modulus ...... 12 FAMILY CHARACTERISTICS Maximum Ratings ...... 15 DC Electrical Characteristics ...... 15 AC Electrical Characteristics ...... 17 Timing Requirements ...... 18 Frequency Characteristics ...... 19 Phase Detector/Lock Detector Output Waveforms...... 19 DESIGN CONSIDERATIONS Phase–Locked Loop — Low–Pass Filter Design ...... 20 Crystal Oscillator Considerations ...... 21 Dual–Modulus Prescaling ...... 22

REV 4 12/99

MOTOROLA Motorola, Inc. 1999 MC145151–2 through MC145158–2 1 MOTOROLA SEMICONDUCTOR TECHNICAL DATA

MC145151-2 Parallel-Input PLL Frequency Synthesizer P SUFFIX Interfaces with Single–Modulus Prescalers PLASTIC DIP CASE 710 28 The MC145151–2 is programmed by 14 parallel–input data lines for the 1 N counter and three input lines for the R counter. The device features consist of a reference oscillator, selectable–reference divider, digital–phase detector, and 14–bit programmable divide–by–N counter. DW SUFFIX SOG PACKAGE The MC145151–2 is an improved–performance drop–in replacement for the 28 CASE 751F MC145151–1. The power consumption has decreased and ESD and latch–up 1 performance have improved. ORDERING INFORMATION • Operating Temperature Range: – 40 to 85°C • Low Power Consumption Through Use of CMOS Technology MC145151P2 Plastic DIP MC145151DW2 SOG Package • 3.0 to 9.0 V Supply Range • On– or Off–Chip Reference Oscillator Operation • Lock Detect Signal •÷ N Counter Output Available PIN ASSIGNMENT • Single Modulus/Parallel Programming • 8 User–Selectable ÷ R Values: 8, 128, 256, 512, 1024, 2048, 2410, 8192 fin 1 28 LD •÷ N Range = 3 to 16383 VSS 2 27 OSCin • “Linearized” Digital Phase Detector Enhances Transfer Function Linearity V 3 26 OSC • Two Error Signal Options: Single–Ended (Three–State) or Double–Ended DD out • Chip Complexity: 8000 FETs or 2000 Equivalent Gates PDout 4 25 N11 RA0 5 24 N10 RA1 6 23 N13 RA2 7 22 N12

φR 8 21 T/R φV 9 20 N9 fV 10 19 N8 N0 11 18 N7 N1 12 17 N6 N2 13 16 N5 N3 14 15 N4

REV 1 8/95

MC145151–2 Motorola, Inc. 1995 through MC145158–2 MOTOROLA 2 MC145151–2 BLOCK DIAGRAM

RA2 RA1 14 x 8 ROM REFERENCE DECODER OSCout RA0 LOCK 14 LD DETECT OSCin 14–BIT ÷ R COUNTER

PHASE DETECTOR PDout A

fin 14–BIT ÷ N COUNTER V DD PHASE φV 14 DETECTOR φ B R T/R TRANSMIT OFFSET ADDER

fV N13 N11 N9 N7 N6 N4 N2 N0

NOTE: N0 – N13 inputs and inputs RA0, RA1, and RA2 have pull–up resistors that are not shown.

PIN DESCRIPTIONS sure that inputs left open remain at a logic 1 and require only an SPST switch to alter data to the zero state. INPUT PINS T/R fin Frequency Input (Pin 1) Transmit/Receive Offset Adder Input (Pin 21) This input controls the offset added to the data provided at Input to the ÷ N portion of the synthesizer. fin is typically derived from loop VCO and is ac coupled into the device. For the N inputs. This is normally used for offsetting the VCO larger amplitude signals (standard CMOS logic levels) dc frequency by an amount equal to the IF frequency of the coupling may be used. transceiver. This offset is fixed at 856 when T/R is low and gives no offset when T/R is high. A pull–up resistor ensures RA0 – RA2 that no connection will appear as a logic 1 causing no offset Reference Address Inputs (Pins 5, 6, 7) addition. These three inputs establish a code defining one of eight possible divide values for the total reference divider, as OSCin, OSCout defined by the table below. Reference Oscillator Input/Output (Pins 27, 26) Pull–up resistors ensure that inputs left open remain at a These pins form an on–chip reference oscillator when con- logic 1 and require only a SPST switch to alter data to the nected to terminals of an external parallel resonant crystal. zero state. Frequency setting capacitors of appropriate value must be connected from OSCin to ground and OSCout to ground. Reference Address Code Total OSCin may also serve as the input for an externally–gener- Divide ated reference signal. This signal is typically ac coupled to RA2 RA1 RA0 Value OSCin, but for larger amplitude signals (standard CMOS 0 0 0 8 logic levels) dc coupling may also be used. In the external 0 0 1 128 reference mode, no connection is required to OSCout. 0 1 0 256 0 1 1 512 OUTPUT PINS 1 0 0 1024 1 0 1 2048 PDout 1 1 0 2410 Phase Detector A Output (Pin 4) 1 1 1 8192 Three–state output of phase detector for use as loop–error signal. Double–ended outputs are also available for this pur- N0 – N11 pose (see φV and φR). N Counter Programming Inputs (Pins 11 – 20, 22 – 25) Frequency fV > fR or fV Leading: Negative Pulses These inputs provide the data that is preset into the ÷ N Frequency fV < fR or fV Lagging: Positive Pulses counter when it reaches the count of zero. N0 is the least sig- Frequency fV = fR and Phase Coincidence: High–Imped- nificant and N13 is the most significant. Pull–up resistors en- ance State

MOTOROLA MC145151–2 through MC145158–2 3 φR, φV nally connected to the phase detector input. With this output Phase Detector B Outputs (Pins 8, 9) available, the ÷ N counter can be used independently.

These phase detector outputs can be combined externally LD for a loop–error signal. A single–ended output is also avail- Lock Detector Output (Pin 28) able for this purpose (see PDout). Essentially a high level when loop is locked (f , f of same If frequency fV is greater than fR or if the phase of fV is R V phase and frequency). Pulses low when loop is out of lock. leading, then error information is provided by φV pulsing low. φ R remains essentially high. POWER SUPPLY If the frequency fV is less than fR or if the phase of fV is lagging, then error information is provided by φR pulsing low. VDD φV remains essentially high. Positive Power Supply (Pin 3) If the frequency of fV = fR and both are in phase, then both The positive power supply potential. This pin may range φ φ V and R remain high except for a small minimum time from + 3 to + 9 V with respect to VSS. period when both pulse low in phase. VSS fV Negative Power Supply (Pin 2) N Counter Output (Pin 10) The most negative supply potential. This pin is usually This is the buffered output of the ÷ N counter that is inter- ground.

TYPICAL APPLICATIONS

2.048 MHz

NC NC

OSCin OSCout fin RA2 RA1 RA0 VOLTAGE MC145151–2 PDout CONTROLLED OSCILLATOR N13N12 N11 N10 N9 N8 N7 N6 N5 N4 N3 N2 N1 N0 5 – 5.5 MHz

0 1 1 1 0 0 0 1 0 0 0 = 5 MHz 1 0 1 0 1 1 1 1 1 0 0 = 5.5 MHz

Figure 1. 5 MHz to 5.5 MHz Local Oscillator Channel Spacing = 1 kHz

LOCK DETECT SIGNAL TRANSMIT: 440.0 – 470.0 MHz “1” “1” “0” RECEIVE: 418.6 – 448.6 MHz CHOICE OF (25 kHz STEPS) DETECTOR OSCout RA2 RA1 RA0 LD fV ERROR SIGNALS PDout OSCin LOOP φ VCO X6 + V VDD R FILTER MC145151–2 f REF. OSC. VSS V fin 10.0417 MHz T/R T: 73.3333 – 78.3333 MHz (ON–CHIP OSC. T: 13.0833 – 18.0833 MHz R: 69.7667 – 74.7667 MHz OPTIONAL) R: 9.5167 – 14.5167 MHz “0” “0” “1” DOWN MIXER RECEIVE CHANNEL PROGRAMMING ÷ TRANSMIT N = 2284 TO 3484 (ADDS 856 TO ÷ N VALUE) X6 60.2500 MHz NOTES: 1. fR = 4.1667 kHz; ÷ R = 2410; 21.4 MHz low side injection during receive. 2. Frequency values shown are for the 440 – 470 MHz band. Similar implementation applies to the 406 – 440 MHz band. For 470 – 512 MHz, consider reference oscillator frequency X9 for mixer injection signal (90.3750 MHz). Figure 2. Synthesizer for Land Mobile Radio UHF Bands

MC145151–2 Data Sheet Continued on Page 15

MC145151–2 through MC145158–2 MOTOROLA 4 MOTOROLA SEMICONDUCTOR TECHNICAL DATA

MC145152-2 Parallel-Input PLL Frequency Synthesizer P SUFFIX Interfaces with Dual–Modulus Prescalers PLASTIC DIP CASE 710 28 The MC145152–2 is programmed by sixteen parallel inputs for the N and A 1 counters and three input lines for the R counter. The device features consist of a reference oscillator, selectable–reference divider, two–output phase detector, 10–bit programmable divide–by–N counter, and 6–bit programmable ÷ A DW SUFFIX SOG PACKAGE counter. 28 CASE 751F The MC145152–2 is an improved–performance drop–in replacement for the 1 MC145152–1. Power consumption has decreased and ESD and latch–up performance have improved. ORDERING INFORMATION • Operating Temperature Range: – 40 to 85°C MC145152P2 Plastic DIP MC145152DW2 SOG Package • Low Power Consumption Through Use of CMOS Technology • 3.0 to 9.0 V Supply Range • On– or Off–Chip Reference Oscillator Operation • Lock Detect Signal PIN ASSIGNMENT • Dual Modulus/Parallel Programming • 8 User–Selectable ÷ R Values: 8, 64, 128, 256, 512, 1024, 1160, 2048 fin 1 28 LD •÷ ÷ N Range = 3 to 1023, A Range = 0 to 63 VSS 2 27 OSCin • Chip Complexity: 8000 FETs or 2000 Equivalent Gates V 3 26 OSC • See Application Note AN980 DD out RA0 4 25 A4 RA1 5 24 A3 RA2 6 23 A0

φR 7 22 A2 φV 8 21 A1 MC 9 20 N9 A5 10 19 N8 N0 11 18 N7 N1 12 17 N6 N2 13 16 N5 N3 14 15 N4

REV 1 8/95

MOTOROLA Motorola, Inc. 1995 MC145151–2 through MC145158–2 5 MC145152–2 BLOCK DIAGRAM

RA2 RA1 12 x 8 ROM REFERENCE DECODER OSCout RA0 12 LOCK LD OSCin 12–BIT ÷ R COUNTER DETECT

φ CONTROL PHASE V LOGIC DETECTOR φR

fin

6–BIT ÷ A COUNTER 10–BIT ÷ N COUNTER

A5 A3 A2 A0 N0 N2 N4 N5 N7 N9

NOTE: N0 – N9, A0 – A5, and RA0 – RA2 have pull–up resistors that are not shown.

PIN DESCRIPTIONS Prescaling section). The A inputs all have internal pull–up resistors that ensure that inputs left open will remain at a INPUT PINS logic 1. f in OSCin, OSCout Frequency Input (Pin 1) Reference Oscillator Input/Output (Pins 27, 26) Input to the positive edge triggered ÷ N and ÷ A counters. These pins form an on–chip reference oscillator when con- fin is typically derived from a dual–modulus prescaler and is nected to terminals of an external parallel resonant crystal. ac coupled into the device. For larger amplitude signals Frequency setting capacitors of appropriate value must be (standard CMOS logic levels) dc coupling may be used. connected from OSCin to ground and OSCout to ground. OSC may also serve as the input for an externally–gener- RA0, RA1, RA2 in ated reference signal. This signal is typically ac coupled to Reference Address Inputs (Pins 4, 5, 6) OSCin, but for larger amplitude signals (standard CMOS These three inputs establish a code defining one of eight logic levels) dc coupling may also be used. In the external possible divide values for the total reference divider. The reference mode, no connection is required to OSCout. total reference divide values are as follows: OUTPUT PINS Reference Address Code Total Divide φR, φV RA2 RA1 RA0 Value Phase Detector B Outputs (Pins 7, 8) 0 0 0 8 These phase detector outputs can be combined externally 0 0 1 64 for a loop–error signal. 0 1 0 128 If the frequency fV is greater than fR or if the phase of fV is 0 1 1 256 leading, then error information is provided by φV pulsing low. 1 0 0 512 φR remains essentially high. 1 0 1 1024 If the frequency fV is less than fR or if the phase of fV is 1 1 0 1160 lagging, then error information is provided by φR pulsing low. 1 1 1 2048 φV remains essentially high. If the frequency of f = f and both are in phase, then both N0 – N9 V R φ and φ remain high except for a small minimum time N Counter Programming Inputs (Pins 11 – 20) V R period when both pulse low in phase. The N inputs provide the data that is preset into the ÷ N counter when it reaches the count of 0. N0 is the least signifi- MC cant digit and N9 is the most significant. Pull–up resistors en- Dual–Modulus Prescale Control Output (Pin 9) sure that inputs left open remain at a logic 1 and require only Signal generated by the on–chip control logic circuitry for a SPST switch to alter data to the zero state. controlling an external dual–modulus prescaler. The MC level will be low at the beginning of a count cycle and will A0 – A5 remain low until the ÷ A counter has counted down from its A Counter Programming Inputs programmed value. At this time, MC goes high and remains (Pins 23, 21, 22, 24, 25, 10) high until the ÷ N counter has counted the rest of the way The A inputs define the number of clock cycles of fin that down from its programmed value (N – A additional counts require a logic 0 on the MC output (see Dual–Modulus since both ÷ N and ÷ A are counting down during the first

MC145151–2 through MC145158–2 MOTOROLA 6 portion of the cycle). MC is then set back low, the counters POWER SUPPLY preset to their respective programmed values, and the above sequence repeated. This provides for a total programmable VDD divide value (NT)= N • P + A where P and P + 1 represent the Positive Power Supply (Pin 3) dual–modulus prescaler divide values respectively for high The positive power supply potential. This pin may range ÷ and low MC levels, N the number programmed into the N from + 3 to + 9 V with respect to V . counter, and A the number programmed into the ÷ A counter. SS LD VSS Lock Detector Output (Pin 28) Negative Power Supply (Pin 2) Essentially a high level when loop is locked (fR, fV of same The most negative supply potential. This pin is usually phase and frequency). Pulses low when loop is out of lock. ground.

TYPICAL APPLICATIONS

NO CONNECTS

“1” “1” “1” LOCK DETECT SIGNAL 150 – 175 MHz 10.24 MHz 5 kHz STEPS NOTE 1 R2 C OSCout RA2 RA1 RA0 LD R1 φR – OSCin R1 VCO φV + MC33171 MC145152–2 R2 MC NOTE 2 + V VDD C VSS fin N9 N0 A5 A0

CHANNEL PROGRAMMING MC12017 ÷ 64/65 PRESCALER NOTES: 1. Off–chip oscillator optional. 2. The φR and φV outputs are fed to an external combiner/loop filter. See the Phase–Locked Loop — Low–Pass Filter Design page for additional information. The φR and φV outputs swing rail–to–rail. Therefore, the user should be careful not to exceed the common mode input range of the op amp used in the combiner/loop filter.

Figure 1. Synthesizer for Land Mobile Radio VHF Bands

MOTOROLA MC145151–2 through MC145158–2 7 RECEIVER 2ND L.O. REF. OSC. NO CONNECTS 30.720 MHz 15.360 MHz (ON–CHIP OSC. RECEIVER FIRST L.O. X2 “1” “1” “1” LOCK DETECT SIGNAL OPTIONAL) 825.030 → 844.980 MHz R2 C (30 kHz STEPS)

OSCout RA2 RA1 RA0 LD R1 φ – OSC R X4 in R1 VCO NOTE 6 φV + + V V MC145152–2 NOTE 7 DD R2 NOTE 5 MC VSS C fin TRANSMITTER X4 MODULATION NOTE 6 N9 N0 A5 A0

MC12017 ÷ 64/65 PRESCALER TRANSMITTER SIGNAL CHANNEL PROGRAMMING NOTE 6 825.030 → 844.980 MHz (30 kHz STEPS) NOTES: 1. Receiver 1st I.F. = 45 MHz, low side injection; Receiver 2nd I.F. = 11.7 MHz, low side injection. 2. Duplex operation with 45 MHz receiver/transmit separation. 3. fR = 7.5 kHz; ÷ R = 2048. 4. Ntotal = N 64 + A = 27501 to 28166; N = 429 to 440; A = 0 to 63. 5. MC145158–2 may be used where serial data entry is desired. 6. High frequency prescalers (e.g., MC12018 [520 MHz] and MC12022 [1 GHz]) may be used for higher frequency VCO and fref implementations. 7. The φR and φV outputs are fed to an external combiner/loop filter. See the Phase–Locked Loop — Low–Pass Filter Design page for additional information. The φR and φV outputs swing rail–to–rail. Therefore, the user should be careful not to exceed the common mode input range of the op amp used in the combiner/loop filter.

Figure 2. 666–Channel, Computer–Controlled, Mobile Radiotelephone Synthesizer for 800 MHz Cellular Radio Systems

MC145152–2 Data Sheet Continued on Page 15

MC145151–2 through MC145158–2 MOTOROLA 8 MOTOROLA SEMICONDUCTOR TECHNICAL DATA

MC145157-2 Serial-Input PLL Frequency Synthesizer P SUFFIX Interfaces with Single–Modulus Prescalers PLASTIC DIP 16 CASE 648 The MC145157–2 has a fully programmable 14–bit reference counter, as well 1 as a fully programmable ÷ N counter. The counters are programmed serially through a common data input and latched into the appropriate counter latch, DW SUFFIX according to the last data bit (control bit) entered. 16 SOG PACKAGE The MC145157–2 is an improved–performance drop–in replacement for the CASE 751G MC145157–1. Power consumption has decreased and ESD and latch–up 1 performance have improved. ORDERING INFORMATION • Operating Temperature Range: – 40 to 85°C • Low Power Consumption Through Use of CMOS Technology MC145157P2 Plastic DIP MC145157DW2 SOG Package • 3.0 to 9.0 V Supply Range • Fully Programmable Reference and ÷ N Counters •÷ R Range = 3 to 16383 •÷ N Range = 3 to 16383 PIN ASSIGNMENT • fV and fR Outputs • Lock Detect Signal OSCin 1 16 φR • Compatible with the Serial Peripheral Interface (SPI) on CMOS MCUs OSCout 2 15 φV • “Linearized” Digital Phase Detector f 3 14 REF • Single–Ended (Three–State) or Double–Ended Phase Detector Outputs V out • Chip Complexity: 6504 FETs or 1626 Equivalent Gates VDD 4 13 fR PDout 5 12 S/Rout VSS 6 11 ENB LD 7 10 DATA

fin 8 9 CLK

REV 1 8/95

MOTOROLA Motorola, Inc. 1995 MC145151–2 through MC145158–2 9 MC145157–2 BLOCK DIAGRAM

14–BIT SHIFT REGISTER

14 fR ENB REFERENCE COUNTER LATCH LOCK LD 14 DETECT

OSCin 14–BIT ÷ R COUNTER PHASE OSC out DETECTOR PDout A REFout

PHASE φ f 14–BIT ÷ N COUNTER V in DETECTOR φ B R 14 ÷ N COUNTER LATCH fV

14 DATA 1–BIT CONTROL 14–BIT SHIFT REGISTER S/Rout S/R CLK

PIN DESCRIPTIONS if the control bit is at a logic low. A logic low on this pin allows the user to change the data in the shift registers without INPUT PINS affecting the counters. ENB is normally low and is pulsed high to transfer data to the latches. fin Frequency Input (Pin 8) OSCin, OSCout Input frequency from VCO output. A rising edge signal on Reference Oscillator Input/Output (Pins 1, 2) this input decrements the ÷ N counter. This input has an These pins form an on–chip reference oscillator when con- inverter biased in the linear region to allow use with ac nected to terminals of an external parallel resonant crystal. coupled signals as low as 500 mV p–p. For larger amplitude Frequency setting capacitors of appropriate value must be signals (standard CMOS logic levels), dc coupling may be connected from OSCin to ground and OSCout to ground. used. OSCin may also serve as the input for an externally–generated reference signal. This signal is typically ac coupled to CLK, DATA OSCin, but for larger amplitude signals (standard CMOS Shift Clock, Serial Data Inputs (Pins 9, 10) logic levels) dc coupling may also be used. In the external Each low–to–high transition of the clock shifts one bit of reference mode, no connection is required to OSCout. data into the on–chip shift registers. The last data bit entered OUTPUT PINS determines which counter storage latch is activated; a logic 1 selects the reference counter latch and a logic 0 selects the PDout ÷ N counter latch. The entry format is as follows: Single–Ended Phase Detector A Output (Pin 5) This single–ended (three–state) phase detector output produces a loop–error signal that is used with a loop filter to

LSB MSB control a VCO.

CONTROL Frequency fV > fR or fV Leading: Negative Pulses Frequency fV < fR or fV Lagging: Positive Pulses FIRST DATA BIT INTO SHIFT REGISTER Frequency fV = fR and Phase Coincidence: High–Imped- ance State ENB Latch Enable Input (Pin 11) φR, φV A logic high on this pin latches the data from the shift regis- Double–Ended Phase Detector B Outputs (Pins 16, 15) ter into the reference divider or ÷ N latches depending on the These outputs can be combined externally for a loop–error control bit. The reference divider latches are activated if the signal. A single–ended output is also available for this pur- control bit is at a logic high and the ÷ N latches are activated pose (see PDout).

MC145151–2 through MC145158–2 MOTOROLA 10 If frequency fV is greater than fR or if the phase of fV is REFout leading, then error information is provided by φV pulsing low. Buffered Reference Oscillator Output (Pin 14) φ R remains essentially high. This output can be used as a second local oscillator, refer- If the frequency fV is less than fR or if the phase of fV is ence oscillator to another frequency synthesizer, or as the φ lagging, then error information is provided by R pulsing low. system clock to a microprocessor controller. φV remains essentially high. If the frequency of fV = fR and both are in phase, then both S/Rout φV and φR remain high except for a small minimum time Shift Register Output (Pin 12) period when both pulse low in phase. This output can be connected to an external shift register to provide band switching, control information, and counter fR, fV R Counter Output, N Counter Output (Pins 13, 3) programming code checking. Buffered, divided reference and fin frequency outputs. The POWER SUPPLY fR and fV outputs are connected internally to the ÷ R and ÷ N counter outputs respectively, allowing the counters to be VDD used independently, as well as monitoring the phase detector Positive Power Supply (Pin 4) inputs. The positive power supply potential. This pin may range from +3 to +9 V with respect to VSS. LD Lock Detector Output (Pin 7) VSS This output is essentially at a high level when the loop is Negative Power Supply (Pin 6) locked (fR, fV of same phase and frequency), and pulses low The most negative supply potential. This pin is usually when loop is out of lock. ground.

MC145157–2 Data Sheet Continued on Page 15

MOTOROLA MC145151–2 through MC145158–2 11 MOTOROLA SEMICONDUCTOR TECHNICAL DATA

MC145158-2 Serial-Input PLL Frequency Synthesizer P SUFFIX Interfaces with Dual–Modulus Prescalers PLASTIC DIP 16 CASE 648 The MC145158–2 has a fully programmable 14–bit reference counter, as well 1 as fully programmable ÷ N and ÷ A counters. The counters are programmed serially through a common data input and latched into the appropriate counter DW SUFFIX latch, according to the last data bit (control bit) entered. 16 SOG PACKAGE The MC145158–2 is an improved–performance drop–in replacement for the CASE 751G MC145158–1. Power consumption has decreased and ESD and latch–up 1 performance have improved. ORDERING INFORMATION • Operating Temperature Range: – 40 to 85°C • Low Power Consumption Through Use of CMOS Technology MC145158P2 Plastic DIP MC145158DW2 SOG Package • 3.0 to 9.0 V Supply Range • Fully Programmable Reference and ÷ N Counters •÷ R Range = 3 to 16383 •÷ N Range = 3 to 1023 PIN ASSIGNMENT • Dual Modulus Capability; ÷ A Range = 0 to 127 φ • fV and fR Outputs OSCin 1 16 R • Lock Detect Signal OSCout 2 15 φV • Compatible with the Serial Peripheral Interface (SPI) on CMOS MCUs f 3 14 REF • “Linearized” Digital Phase Detector V out • Single–Ended (Three–State) or Double–Ended Phase Detector Outputs VDD 4 13 fR • Chip Complexity: 6504 FETs or 1626 Equivalent Gates PDout 5 12 MC VSS 6 11 ENB LD 7 10 DATA

fin 8 9 CLK

REV 1 8/95

MC145151–2 Motorola, Inc. 1995 through MC145158–2 MOTOROLA 12 MC145158–2 BLOCK DIAGRAM

14–BIT SHIFT REGISTER

14 fR ENB REFERENCE COUNTER LATCH LOCK LD 14 DETECT

OSCin 14–BIT ÷ R COUNTER PHASE OSC out DETECTOR PDout CONTROL LOGIC A REFout

7–BIT ÷ A 10–BIT ÷ N PHASE φ f V in COUNTER COUNTER DETECTOR φ B R 7 10 ÷ A COUNTER ÷ N COUNTER f LATCH LATCH V

7 10 DATA 1–BIT CONTROL 7–BIT S/R 10–BIT S/R MC S/R CLK

PIN DESCRIPTIONS ÷ A ÷ N

INPUT PINS LSB LSB f MSB MSB in CONTROL Frequency Input (Pin 8)

Input frequency from VCO output. A rising edge signal on FIRST DATA BIT INTO SHIFT REGISTER this input decrements the ÷ A and ÷ N counters. This input has an inverter biased in the linear region to allow use with ENB ac coupled signals as low as 500 mV p–p. For larger ampli- Latch Enable Input (Pin 11) tude signals (standard CMOS logic levels), dc coupling may A logic high on this pin latches the data from the shift regis- be used. ter into the reference divider or ÷ N, ÷ A latches depending on the control bit. The reference divider latches are activated if CLK, DATA the control bit is at a logic high and the ÷ N, ÷ A latches are Shift Clock, Serial Data Inputs (Pins 9, 10) activated if the control bit is at a logic low. A logic low on this pin allows the user to change the data in the shift registers Each low–to–high transition of the CLK shifts one bit of without affecting the counters. ENB is normally low and is data into the on–chip shift registers. The last data bit entered pulsed high to transfer data to the latches. determines which counter storage latch is activated; a logic 1 selects the reference counter latch and a logic 0 selects the OSCin, OSCout ÷ A, ÷ N counter latch. The data entry format is as follows: Reference Oscillator Input/Output (Pins 1, 2) These pins form an on–chip reference oscillator when con- ÷ R nected to terminals of an external parallel resonant crystal. Frequency setting capacitors of appropriate value must be connected from OSCin to ground and OSCout to ground. OSCin may also serve as the input for an externally–gener- LSB MSB ated reference signal. This signal is typically ac coupled to CONTROL OSCin, but for larger amplitude signals (standard CMOS logic levels) dc coupling may also be used. In the external refer- FIRST DATA BIT INTO SHIFT REGISTER ence mode, no connection is required to OSCout.

MOTOROLA MC145151–2 through MC145158–2 13 OUTPUT PINS dual–modulus prescaler divide values respectively for high and low modulus control levels, N the number programmed ÷ PD into the N counter, and A the number programmed into the out ÷ Phase Detector A Output (Pin 5) A counter. Note that when a prescaler is needed, the dual– modulus version offers a distinct advantage. The dual– This single–ended (three–state) phase detector output modulus prescaler allows a higher reference frequency at produces a loop–error signal that is used with a loop filter to the phase detector input, increasing system performance ca- control a VCO. pability, and simplifying the loop filter design. Frequency fV > fR or fV Leading: Negative Pulses Frequency f < f or f Lagging: Positive Pulses V R V fR, fV Frequency fV = fR and Phase Coincidence: High–Imped- R Counter Output, N Counter Output (Pins 13, 3) ance State Buffered, divided reference and fin frequency outputs. The ÷ φR, φV fR and fV outputs are connected internally to the R and Phase Detector B Outputs (Pins 16, 15) ÷ N counter outputs respectively, allowing the counters to be used independently, as well as monitoring the phase detector Double–ended phase detector outputs. These outputs can inputs. be combined externally for a loop–error signal. A single– ended output is also available for this purpose (see PD ). out LD If frequency f is greater than f or if the phase of f is V R V Lock Detector Output (Pin 7) leading, then error information is provided by φV pulsing low. φR remains essentially high. This output is essentially at a high level when the loop is If the frequency fV is less than fR or if the phase of fV is locked (fR, fV of same phase and frequency), and pulses low lagging, then error information is provided by φR pulsing low. when loop is out of lock. φV remains essentially high. REF If the frequency of fV = fR and both are in phase, then both out Buffered Reference Oscillator Output (Pin 14) φV and φR remain high except for a small minimum time period when both pulse low in phase. This output can be used as a second local oscillator, reference oscillator to another frequency synthesizer, or as the MC system clock to a microprocessor controller. Dual–Modulus Prescale Control Output (Pin 12) This output generates a signal by the on–chip control logic POWER SUPPLY circuitry for controlling an external dual–modulus prescaler. The MC level is low at the beginning of a count cycle and V remains low until the ÷ A counter has counted down from its DD Positive Power Supply (Pin 4) programmed value. At this time, MC goes high and remains high until the ÷ N counter has counted the rest of the way The positive power supply potential. This pin may range down from its programmed value (N – A additional counts from + 3 to + 9 V with respect to VSS. since both ÷ N and ÷ A are counting down during the first portion of the cycle). MC is then set back low, the counters pre- VSS set to their respective programmed values, and the above Negative Power Supply (Pin 6) sequence repeated. This provides for a total programmable The most negative supply potential. This pin is usually divide value (NT) = N P + A where P and P + 1 represent the ground.

MC145151–2 through MC145158–2 MOTOROLA 14 MC14515X–2 FAMILY CHARACTERISTICS AND DESCRIPTIONS

MAXIMUM RATINGS* (Voltages Referenced to VSS) Symbol Parameter Value Unit These devices contain protection circuitry to protect against damage due to high static VDD DC Supply Voltage – 0.5 to + 10.0 V voltages or electric fields. However, precau- tions must be taken to avoid applications of any V , V Input or Output Voltage (DC or Transient) – 0.5 to V + 0.5 V in out DD voltage higher than maximum rated voltages except SW1, SW2 to these high–impedance circuits. For proper Vout Output Voltage (DC or Transient), – 0.5 to + 15 V operation, Vin and Vout should be constrained ≤ ≤ SW1, SW2 (Rpull–up = 4.7 kΩ) to the range VSS (Vin or Vout) VDD except for SW1 and SW2. ± Iin, Iout Input or Output Current (DC or Transient), 10 mA SW1 and SW2 can be tied through external per Pin resistors to voltages as high as 15 V, indepen- dent of the supply voltage. IDD, ISS Supply Current, VDD or VSS Pins ± 30 mA Unused inputs must always be tied to an PD Power Dissipation, per Package† 500 mW appropriate logic voltage level (e.g., either VSS or V ), except for inputs with pull–up devices. Tstg Storage Temperature – 65 to + 150 °C DD Unused outputs must be left open. TL Lead Temperature, 1 mm from Case for 260 °C 10 seconds * Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the limits in the Electrical Characteristics tables or Pin Descriptions section. †Power Dissipation Temperature Derating: Plastic DIP: – 12 mW/°C from 65 to 85°C SOG Package: – 7 mW/°C from 65 to 85°C

ELECTRICAL CHARACTERISTICS (Voltages Referenced to VSS) – 40°C 25°C 85°C VDD Symbol Parameter Test Condition V Min Max Min Max Min Max Unit

VDD Power Supply Voltage — 3 9 3 9 3 9 V Range

Iss Dynamic Supply Current fin = OSCin = 10 MHz, 3 — 3.5 — 3 — 3 mA 1 V p–p ac coupled sine 5 — 10 — 7.5 — 7.5 wave 9 — 30 — 24 — 24 R = 128, A = 32, N = 128

ISS Quiescent Supply Current Vin = VDD or VSS 3 — 800 — 800 — 1600 µA (not including pull–up Iout = 0 µA 5 — 1200 — 1200 — 2400 current component) 9 — 1600 — 1600 — 3200

Vin Input Voltage — fin, OSCin Input ac coupled sine wave — 500 — 500 — 500 — mV p–p VIL Low–Level Input Voltage Vout ≥ 2.1 V Input dc 3 — 0 — 0 — 0 V — fin, OSCin Vout ≥ 3.5 V coupled 5 — 0 — 0 — 0 Vout ≥ 6.3 V square wave 9 — 0 — 0 — 0 VIH High–Level Input Voltage Vout ≤ 0.9 V Input dc 3 3.0 — 3.0 — 3.0 — V — fin, OSCin Vout ≤ 1.5 V coupled 5 5.0 — 5.0 — 5.0 — Vout ≤ 2.7 V square wave 9 9.0 — 9.0 — 9.0 — VIL Low–Level Input Voltage 3 — 0.9 — 0.9 — 0.9 V — except fin, OSCin 5 — 1.5 — 1.5 — 1.5 9 — 2.7 — 2.7 — 2.7

VIH High–Level Input Voltage 3 2.1 — 2.1 — 2.1 — V — except fin, OSCin 5 3.5 — 3.5 — 3.5 — 9 6.3 — 6.3 — 6.3 —

Iin Input Current (fin, OSCin) Vin = VDD or VSS 9 ± 2 ± 50 ± 2 ± 25 ± 2 ± 22 µA IIL Input Leakage Current Vin = VSS 9 — – 0.3 — – 0.1 — – 1.0 µA (Data, CLK, ENB — without pull–ups)

IIH Input Leakage Current (all Vin = VDD 9 — 0.3 — 0.1 — 1.0 µA inputs except fin, OSCin) (continued)

MOTOROLA MC145151–2 through MC145158–2 15 DC ELECTRICAL CHARACTERISTICS (continued) – 40°C 25°C 85°C VDD Symbol Parameter Test Condition V Min Max Min Max Min Max Unit

IIL Pull–up Current (all inputs Vin = VSS 9 – 20 – 400 – 20 – 200 – 20 – 170 µA with pull–ups)

Cin Input Capacitance — — 10 — 10 — 10 pF VOL Low–Level Output Iout ≈ 0 µA 3 — 0.9 — 0.9 — 0.9 V Voltage — OSCout Vin = VDD 5 — 1.5 — 1.5 — 1.5 9 — 2.7 — 2.7 — 2.7

VOH High–Level Output Iout ≈ 0 µA 3 2.1 — 2.1 — 2.1 — V Voltage — OSCout Vin = VSS 5 3.5 — 3.5 — 3.5 — 9 6.3 — 6.3 — 6.3 —

VOL Low–Level Output Iout ≈ 0 µA 3 — 0.05 — 0.05 — 0.05 V Voltage — Other Outputs 5 — 0.05 — 0.05 — 0.05 9 — 0.05 — 0.05 — 0.05

VOH High–Level Output Iout ≈ 0 µA 3 2.95 — 2.95 — 2.95 — V Voltage — Other Outputs 5 4.95 — 4.95 — 4.95 — 9 8.95 — 8.95 — 8.95 —

V(BR)DSS Drain–to–Source Rpull–up = 4.7 kΩ — 15 — 15 — 15 — V Breakdown Voltage — SW1, SW2

IOL Low–Level Sinking Vout = 0.3 V 3 1.30 — 1.10 — 0.66 — mA Current — MC Vout = 0.4 V 5 1.90 — 1.70 — 1.08 — Vout = 0.5 V 9 3.80 — 3.30 — 2.10 — IOH High–Level Sourcing Vout = 2.7 V 3 – 0.60 — – 0.50 — – 0.30 — mA Current — MC Vout = 4.6 V 5 – 0.90 — – 0.75 — – 0.50 — Vout = 8.5 V 9 – 1.50 — – 1.25 — – 0.80 — IOL Low–Level Sinking Vout = 0.3 V 3 0.25 — 0.20 — 0.15 — mA Current — LD Vout = 0.4 V 5 0.64 — 0.51 — 0.36 — Vout = 0.5 V 9 1.30 — 1.00 — 0.70 — IOH High–Level Sourcing Vout = 2.7 V 3 – 0.25 — – 0.20 — – 0.15 — mA Current — LD Vout = 4.6 V 5 – 0.64 — – 0.51 — – 0.36 — Vout = 8.5 V 9 – 1.30 — – 1.00 — – 0.70 — IOL Low–Level Sinking Vout = 0.3 V 3 0.80 — 0.48 — 0.24 — mA Current — SW1, SW2 Vout = 0.4 V 5 1.50 — 0.90 — 0.45 — Vout = 0.5 V 9 3.50 — 2.10 — 1.05 — IOL Low–Level Sinking Vout = 0.3 V 3 0.44 — 0.35 — 0.22 — mA Current — Other Outputs Vout = 0.4 V 5 0.64 — 0.51 — 0.36 — Vout = 0.5 V 9 1.30 — 1.00 — 0.70 — IOH High–Level Sourcing Vout = 2.7 V 3 – 0.44 — – 0.35 — – 0.22 — mA Current — Other Outputs Vout = 4.6 V 5 – 0.64 — – 0.51 — – 0.36 — Vout = 8.5 V 9 – 1.30 — – 1.00 — – 0.70 — IOZ Output Leakage Current — Vout = VDD or VSS 9 — ± 0.3 — ± 0.1 — ± 1.0 µA PDout Output in Off State IOZ Output Leakage Current — Vout = VDD or VSS 9 — ± 0.3 — ± 0.1 — ± 3.0 µA SW1, SW2 Output in Off State

Cout Output Capacitance — PDout — Three–State — — 10 — 10 — 10 pF PDout

MC145151–2 through MC145158–2 MOTOROLA 16 AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, Input tr = tf = 10 ns) VDD Guaranteed Limit Guaranteed Limit Symbol Parameter V 25°C – 40 to 85°C Unit

tPLH, tPHL Maximum Propagation Delay, fin to MC 3 110 120 ns (Figures 1 and 4) 5 60 70 9 35 40

tPHL Maximum Propagation Delay, ENB to SW1, SW2 3 160 180 ns (Figures 1 and 5) 5 80 95 9 50 60

tw Output Pulse Width, φR, φV, and LD with fR in Phase with fV 3 25 to 200 25 to 260 ns (Figures 2 and 4) 5 20 to 100 20 to 125 9 10 to 70 10 to 80

tTLH Maximum Output Transition Time, MC 3 115 115 ns (Figures 3 and 4) 5 60 75 9 40 60

tTHL Maximum Output Transition Time, MC 3 60 70 ns (Figures 3 and 4) 5 34 45 9 30 38

tTLH, tTHL Maximum Output Transition Time, LD 3 180 200 ns (Figures 3 and 4) 5 90 120 9 70 90

tTLH, tTHL Maximum Output Transition Time, Other Outputs 3 160 175 ns (Figures 3 and 4) 5 80 100 9 60 65

SWITCHING WAVEFORMS

VDD INPUT 50% — VSS tw tPLH tPHL φR, φV, LD* 50% OUTPUT 50% *fR in phase with fV. Figure 1. Figure 2.

tTLH tTHL ANY 90% OUTPUT 10%

Figure 3.

VDD TEST POINT TEST POINT

OUTPUT OUTPUT 15 kΩ DEVICE DEVICE UNDER UNDER CL* CL* TEST TEST

* Includes all probe and fixture capacitance. * Includes all probe and fixture capacitance.

Figure 4. Test Circuit Figure 5. Test Circuit

MOTOROLA MC145151–2 through MC145158–2 17 TIMING REQUIREMENTS (Input tr = tf = 10 ns unless otherwise indicated) VDD Guaranteed Limit Guaranteed Limit Symbol Parameter V 25°C – 40 to 85°C Unit

fclk Serial Data Clock Frequency, Assuming 25% Duty Cycle 3 dc to 5.0 dc to 3.5 MHz NOTE: Refer to CLK tw(H) below 5 dc to 7.1 dc to 7.1 (Figure 6) 9 dc to 10 dc to 10

tsu Minimum Setup Time, Data to CLK 3 30 30 ns (Figure 7) 5 20 20 9 18 18

th Minimum Hold Time, CLK to Data 3 40 40 ns (Figure 7) 5 20 20 9 15 15

tsu Minimum Setup Time, CLK to ENB 3 70 70 ns (Figure 7) 5 32 32 9 25 25

trec Minimum Recovery Time, ENB to CLK 3 5 5 ns (Figure 7) 5 10 10 9 20 20

tw(H) Minimum Pulse Width, CLK and ENB 3 50 70 ns (Figure 6) 5 35 35 9 25 25

tr, tf Maximum Input Rise and Fall Times — Any Input 3 5 5 µs (Figure 8) 5 4 4 9 2 2

SWITCHING WAVEFORMS

— VDD tw(H) DATA 50% — V V CLK, DD SS 50% tsu ENB th 1 * VSS — VDD 4 fclk CLK 50% LAST FIRST CLK CLK VSS *Assumes 25% Duty Cycle. tsu trec — VDD Figure 6. ENB 50% VSS PREVIOUS DATA t t t f LATCHED ANY 90% — VDD OUTPUT 10% VSS Figure 7.

Figure 8.

MC145151–2 through MC145158–2 MOTOROLA 18 FREQUENCY CHARACTERISTICS (Voltages References to VSS, CL = 50 pF, Input tr = tf =10 ns unless otherwise indicated) – 40°C 25°C 85°C VDD Symbol Parameter Test Condition V Min Max Min Max Min Max Unit

fi Input Frequency R ≥ 8, A ≥ 0, N ≥ 8 3 — 6 — 6 — 6 MHz (fin, OSCin) Vin = 500 mV p–p 5 — 15 — 15 — 15 ac coupled sine wave 9 — 15 — 15 — 15 R ≥ 8, A ≥ 0, N ≥ 8 3 — 12 — 12 — 7 MHz Vin = 1 V p–p ac coupled 5 — 22 — 20 — 20 sine wave 9 — 25 — 22 — 22 R ≥ 8, A ≥ 0, N ≥ 8 3 — 13 — 12 — 8 MHz Vin = VDD to VSS 5 — 25 — 22 — 22 dc coupled square wave 9 — 25 — 25 — 25

NOTE: Usually, the PLL’s propagation delay from fin to MC plus the setup time of the prescaler determines the upper frequency limit of the system. The upper frequency limit is found with the following formula: f = P/(tP + tset) where f is the upper frequency in Hz, P is the lower of the dual modulus prescaler ratios, tP is the fin to MC propagation delay in seconds, and tset is the prescaler setup time in seconds. For example, with a 5 V supply, the fin to MC delay is 70 ns. If the MC12028A prescaler is used, the setup time is 16 ns. Thus, if the 64/65 ratio is utilized, the upper frequency limit is f = P/(tP + tset) = 64/(70 + 16) = 744 MHz.

fR VH REFERENCE OSC ÷ R VL fV VH FEEDBACK ÷ (fin N) VL * VH HIGH IMPEDANCE PDout

VL VH φR VL VH φV VL VH LD VL

VH = High Voltage Level. VL = Low Voltage Level. * At this point, when both fR and fV are in phase, the output is forced to near mid–supply. NOTE: The PDout generates error pulses during out–of–lock conditions. When locked in phase and frequency the output is high and the voltage at this pin is determined by the low–pass filter capacitor.

Figure 9. Phase Detector/Lock Detector Output Waveforms

MOTOROLA MC145151–2 through MC145158–2 19 DESIGN CONSIDERATIONS

PHASE–LOCKED LOOP — LOW–PASS FILTER DESIGN

A) PD KφKVCO out VCO ωn = R1 NR1C φR — C Nωn ζ φ = V — 2KφKVCO 1 F(s) = R1sC + 1

B) PD VCO out KφKVCO R1 ωn = φ NC(R1 + R2) R — R2 φ ǒ N Ǔ V — C ζ = 0.5 ωn R2C+ KφKVCO

R2sC + 1 F(s) = (R1 +R2)sC + 1

R2 C) PDout — KφKVCO ω = n NCR R1 C 1 φ _ R ω φ A VCO nR2C V + ζ = R1 2 ASSUMING GAIN A IS VERY LARGE, THEN: R2 R sC + 1 C F(s) = 2 R1sC

NOTE: Sometimes R1 is split into two series resistors, each R1 ÷ 2. A capacitor CC is then placed from the midpoint to ground to further filter φV and φR. The value of CC should be such that the corner frequency of this network does not significantly affect ωn. The φR and φV outputs swing rail–to–rail. Therefore, the user should be careful not to exceed the common mode input range of the op amp used in the combiner/loop filter.

DEFINITIONS: N = Total Division Ratio in feedback loop Kφ (Phase Detector Gain) = VDD/4π for PDout Kφ (Phase Detector Gain) = VDD/2π for φV and φR 2π∆fVCO KVCO (VCO Gain) = ∆VVCO 2πfr for a typical design wn (Natural Frequency) ≈ (at phase detector input). 10 Damping Factor: ζ ≅ 1

RECOMMENDED READING: Gardner, Floyd M., Phaselock Techniques (second edition). New York, Wiley–Interscience, 1979. Manassewitsch, Vadim, Frequency Synthesizers: Theory and Design (second edition). New York, Wiley–Interscience, 1980. Blanchard, Alain, Phase–Locked Loops: Application to Coherent Receiver Design. New York, Wiley–Interscience, 1976. Egan, William F., Frequency Synthesis by Phase Lock. New York, Wiley–Interscience, 1981. Rohde, Ulrich L., Digital PLL Frequency Synthesizers Theory and Design. Englewood Cliffs, NJ, Prentice–Hall, 1983. Berlin, Howard M., Design of Phase–Locked Loop Circuits, with Experiments. Indianapolis, Howard W. Sams and Co., 1978. Kinley, Harold, The PLL Synthesizer Cookbook. Blue Ridge Summit, PA, Tab Books, 1980. AN535, Phase–Locked Loop Design Fundamentals, Motorola Semiconductor Products, Inc., 1970. AR254, Phase–Locked Loop Design Articles, Motorola Semiconductor Products, Inc., Reprinted with permission from Electronic Design, 1987.

MC145151–2 through MC145158–2 MOTOROLA 20 CRYSTAL OSCILLATOR CONSIDERATIONS CL values. The shunt load capacitance, CL, presented across the crystal can be estimated to be: The following options may be considered to provide a reference frequency to Motorola’s CMOS frequency synthe- CinCout C1 • C2 CL = + Ca + Co + sizers. Cin + Cout C1 + C2 where Use of a Hybrid Crystal Oscillator Cin = 5 pF (see Figure 11) Commercially available temperature–compensated crystal Cout = 6 pF (see Figure 11) oscillators (TCXOs) or crystal–controlled data clock oscilla- Ca = 1 pF (see Figure 11) tors provide very stable reference frequencies. An oscillator CO = the crystal’s holder capacitance capable of sinking and sourcing 50 µA at CMOS logic levels (see Figure 12) may be direct or dc coupled to OSCin. In general, the highest C1 and C2 = external capacitors (see Figure 10) frequency capability is obtained utilizing a direct–coupled square wave having a rail–to–rail (VDD to VSS) voltage Ca swing. If the oscillator does not have CMOS logic levels on the outputs, capacitive or ac coupling to OSC may be used. in Cin Cout OSCout, an unbuffered output, should be left floating. For additional information about TCXOs and data clock oscillators, please consult the latest version of the eem Elec- tronic Engineers Master Catalog, the Gold Book, or similar Figure 11. Parasitic Capacitances of the Amplifier publications. RS LS CS Design an Off–Chip Reference 1 2 1 2 The user may design an off–chip crystal oscillator using ICs specifically developed for crystal oscillator applications, such as the MC12061 MECL device. The reference signal CO from the MECL device is ac coupled to OSCin. For large amplitude signals (standard CMOS logic levels), dc coupling is 1 Re Xe 2 used. OSCout, an unbuffered output, should be left floating. In general, the highest frequency capability is obtained with a direct–coupled square wave having rail–to–rail voltage NOTE: Values are supplied by crystal manufacturer swing. (parallel resonant crystal).

Use of the On–Chip Oscillator Circuitry Figure 12. Equivalent Crystal Networks The on–chip amplifier (a digital inverter) along with an ap- The oscillator can be “trimmed” on–frequency by making a propriate crystal may be used to provide a reference source portion or all of C1 variable. The crystal and associated com- frequency. A fundamental mode crystal, parallel resonant at ponents must be located as close as possible to the OSCin the desired operating frequency, should be connected as and OSCout pins to minimize distortion, stray capacitance, shown in Figure 10. stray inductance, and startup stabilization time. In some cases, stray capacitance should be added to the value for Cin FREQUENCY and Cout. Rf SYNTHESIZER Power is dissipated in the effective series resistance of the crystal, Re, in Figure 12. The drive level specified by the crystal manufacturer is the maximum stress that a crystal can withstand without damage or excessive shift in frequency. R1 in Figure 10 limits the drive level. The use of R1 may not be OSCin OSCout R1* necessary in some cases (i.e., R1 = 0 Ω). To verify that the maximum dc supply voltage does not C1 C2 overdrive the crystal, monitor the output frequency as a function of voltage at OSCout. (Care should be taken to minimize loading.) The frequency should increase very slightly as the * May be deleted in certain cases. See text. dc supply voltage is increased. An overdriven crystal will de- crease in frequency or become unstable with an increase in Figure 10. Pierce Crystal Oscillator Circuit supply voltage. The operating supply voltage must be re- duced or R1 must be increased in value if the overdriven For VDD = 5.0 V, the crystal should be specified for a load- condition exists. The user should note that the oscillator ing capacitance, CL, which does not exceed 32 pF for fre- start–up time is proportional to the value of R1. quencies to approximately 8.0 MHz, 20 pF for frequencies in Through the process of supplying crystals for use with the area of 8.0 to 15 MHz, and 10 pF for higher frequencies. CMOS inverters, many crystal manufacturers have devel- These are guidelines that provide a reasonable compromise oped expertise in CMOS oscillator design with crystals. Dis- between IC capacitance, drive capability, swamping varia- cussions with such manufacturers can prove very helpful tions in stray and IC input/output capacitance, and realistic (see Table 1).

MOTOROLA MC145151–2 through MC145158–2 21 Table 1. Partial List of Crystal Manufacturers

Motorola — Internet Address http://motorola.com (Search for resonators)

United States Crystal Corp.

Crystek Crystal

Statek Corp.

Fox Electronics

NOTE: Motorola cannot recommend one supplier over another and in no way suggests that this is a complete listing of crystal manufacturers.