ML145145 4–Bit Data Bus Input PLL Frequency Synthesizer INTERFACES WITH SINGLE–MODULUS PRESCALERS Legacy Device: Motorola MC145145-2 The ML145145 is programmed by a 4–bit input, with strobe and address lines. The device features consist of a reference oscillator, 12–bit programmable reference divider, digital phase detector, 14–bit programmable divide–by–N counter, and the necessary latch circuitry for accepting the 4–bit input data. P DIP 18 = VP PLASTIC DIP CASE 707 18 1 SOG 20 = -6P SOG PACKAGE CASE 751D 20 • Operating Temperature Range: TA – 40 to 85°C • Low Power Consumption Through the Use of CMOS Technology • 3.0 to 9.0 V Supply Range • Single Modulus 4–Bit Data Bus Programming • ÷N Range = 3 to 16,383, ÷R Range = 3 to 4,095 • “Linearized” Digital Phase Detector Enhances Transfer Function Linearity • Two Error Signal Options: Single–Ended (Three–State) Double–Ended 1 CROSS REFERENCE/ORDERING INFORMATION MOTOROLA LANSDALE PACKAGE P DIP 18 MC145145P1 ML145145VP SOG 20 MC145145DW2 ML145145-6P Note: Lansdale lead free (Pb) product, as it becomes available, will be identified by a part number prefix change from ML to MLE. PIN ASSIGNMENTS PLASTIC DIP BLOCK DIAGRAM REFout OSCin 12–BIT R COUNTER OSCout D0 D1 D2 D3 A0 A1 A2 LATCH 4 LATCH 5 LATCH 6 fR LATCH CONTROL CIRCUITRY fV PHASE DETECTOR A LATCH 0 LATCH 1 LATCH 2 L3 PHASE DETECTOR B 1 18 D2 D0 2 17 D3 fin 3 16 REFout VSS 4 15 φR VDD 5 14 φV OSCin 6 13 LD OSCout 7 12 PDout A0 8 11 ST A1 9 10 A2 LD PDout LATCHES ST fin LOCK DETECT D1 φV φR 14–BIT N COUNTER SOG PACKAGE D1 1 20 D2 D0 2 19 D3 NC 3 18 REFout fin 4 17 φR VSS 5 16 φV VDD 6 15 LD OSCin 7 14 PDout OSCout 8 13 ST A0 9 12 A2 A1 10 11 NC NC = NO CONNECTION Page 1 of 12 www.lansdale.com Issue b ML145145 Page 2 of 12 LANSDALE Semiconductor, Inc. www.lansdale.com Issue b ML145145 Page 3 of 12 LANSDALE Semiconductor, Inc. www.lansdale.com Issue b ML145145 Page 4 of 12 LANSDALE Semiconductor, Inc. www.lansdale.com Issue b ML145145 Page 5 of 12 LANSDALE Semiconductor, Inc. www.lansdale.com Issue b ML145145 LANSDALE Semiconductor, Inc. PIN DESCRIPTIONS latch, the falling edge of strobe latches data into the latch. This pin should normally be held low to avoid loading latches with invalid data. INPUT PINS D0 – D3 Data Inputs (PDIP – Pins 2, 1, 18, 17; SOG – Pins 2, 1, 20, 19) Information at these inputs is transferred to the internal latches when the ST input is in the high state. D3 is most signigicant bit. f in Frequency Input (PDIP – Pin 3, SOG – Pin 4) Input to ÷N portion of synthesizer. f in is typically derived from the loop VCO and is ac couples. For larger amplitude signals (standard CMOS – logic levels) dc coupling may be used. OSCin/OSCout Reference Oscillator Input/Output (PDIP – Pins 6, 7; SOG – Pins 7, 8) These pins form an on–chip reference oscillator when connected 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 input for an externally–generated reference signal. This signal is typically AC coupled to OSCin but for larger amplitude signals (standard CMOS–logic levels) DC coupling may also be used. In the external refrence mode, no connection is required to OSCout. A0 – A2 Address Inputs (PDIP – Pins 8, 9, 10; SOG – Pins 9, 10, 12) A0, A1 and A2 are used to define which latch receives the information on the data input lines. The addresses refer to the following latches: OUTPUT PINS PDout Single–Ended Phase Detector output (PDIP – Pin 12, SOG – Pin 14) Three–state output of phase detector for use as loop–error signal. Frequency fV > fR or fV Leading: Negative Pulses Frequency fV < fR or fV Lagging: Positive Pulses Frequency fV = fR and Phase Coincidence: High–Impedance State LD Lock Detector Signal (PDIP – Pin 13, SOG – Pin 15) High level when loop is locked (fR, fV of same phase and frequency). Pulses low when loop is out of lock. φV, φR Phase Detect or Outputs (PDIP – Pin 12, SOG – Pin 14) These phase detector outputs can be combined externally for a loop–error signal. A single–ended output is also available for this purpose (see PDout). If frequency fV is greater than fR or if the phase of fV is leading, then error information is provided by φV pulsing low. φR remains essentially high. If the frequency of fV – fR and both are in phase, then both φV and φR remain high except for a small minimum time period when both pulse low in phase. REFout Buffered Reference Output (DIP – Pin 16, SOG – Pin 18) Buffered output of on–chip reference oscillator or externally provided reference–input signal. POWER SUPPLY PINS ST Strobe Transfer (PDIP – Pin 11, SOG – Pin 13) The rising edge of strobe transfers data into the addressed Page 6 of 12 VSS Ground (PDIP – Pin 4, SOG – Pin 5) Circuit Ground VDD Positive Power Supply (PDIP – Pin 5, SOG – Pin 6) The positive supply voltage may range from 3.0 to 9.0 V with respect to VSS. www.lansdale.com Issue b ML145145 Page 7 of 12 LANSDALE Semiconductor, Inc. www.lansdale.com Issue b ML145145 LANSDALE Semiconductor, Inc. CRYSTAL OSCILLATOR CONSIDERATIONS The following options may be considered to provide a reference frequency to Motorola’s CMOS frequency sytnthesizers. Use of a Hybrid Crystal Oscillator Commercially available temperature–compensated crystal oscillators (TCXOs) or crystal–controlled data clock oscillators provide very stable reference frequencies. An oscillator capable of sinking and sourcing 50 µA at CMOS logic levels may be direct or DC coupled to OSCin. In general, the highest frequency capability is obtained utilizing a direct–coupled square wave having a rail–to–rail (VDD to VSS) voltage swing. If the oscillator does not have CMOS logic levels on the outputs, capacitive or AC coupling to OSCin may be used. OSCout, and unbuffered output, should be left floating. For additional information about TCXOs and data clock oscillators, please consult the latest version of the eem Electronic Engineers Master Catalog, the Gold Book, or similar publications. Design an Off–Chip Reference The user may design an off–chip crystal oscillator using ICs specifically developed for crystal oscillator applications, such as the ML12061 MECL device. The reference signal from the MECL device is ac coupled to OSCin. For large amplitude signals (standard CMOS logic levels), DC coupling is used. OSCout, an unbuffered output, should be left floating. In general, the highest freqency capability is obtained with a direct–coupled square wave having rail–to–rail voltage swing. Use of the On–Chip Oscillator Circuitry The on–chip amplifier (a digital inverter) along with an appropriate crystal may be used to provide a reference source frequency. A fundamental mode crystal, parallel resonant at the desired operating frequency, should be connected as shown in Figure 7. For VDD = 5.0 V, the crystal should be specified for a loading capactitanc. CL, which does not exceed 32 pf for frequencies to approximately 8.0 to 15 MHz and 10 pF for higher frequencies. These are guidelines that provide a reasonable compromise between IC capacitance, drive capability, swamping c–variations in stray and IC input/output capacitance, and realistic CL values. The shunt load capacitance. CL, presented across the crystal can be estimated to be: portion of all of C1 variable. The crystal and associated components must be located as close as possible to the OSCin and OSCout pins to minimize distortion, stray capacitance, stray inductance and startup stablilization time. In some cases, stray capacitance should be added to the value for Cin and Cout. Power is dissipated in the effective series resistance of the crystal Re, in Figure 9. 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 7 limits the drive level. The use of R1 may not be necessary in some cases (i.e., R1 = 0 Ω) To verify that the maximum dc supply voltage does not 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 dc supply voltage is increased. An overdriven crystal will decrease in frequency or become unstable with an increase in supply voltage. The operating supply voltage must be reduced or R1 must be increased in value if the overdriven condition exists. The user should note that the oscillator start–up time is proportional to the value of R1. Through the process of supplying crystals for use with CMOS inverters, many crystal manufactureres have developed expertise in CMOS oscillator design with crystals. Discussions with such manufacturers can prove very helpful (see Table 1). where Cin = 5.0 pf (see Figure 8) Cout = 6.0 pf (see Figure 8) Ca = 1.0 pf (see Figure 8) CO = the crystal’s holder capacitance (see Figure 9) C1 and C2 = external capacitors (see Figure 7) The oscillator can be “trimmed” on–frequency by making a Page 8 of 12 www.lansdale.com Issue b ML145145 LANSDALE Semiconductor, Inc. RECOMMENDED READING Technical Note TN–24, Stated Corp. Technical Note TN–\7, Stated Corp. E. Hafner, “The Piezoelectric Crystal Unit – Definitions and Method of Measurement”, Proc IEEE, Vol. 57, No. 2 Feb., 1969 D. Kemper, L. Rosine, “Quartz Crystals for Frequency Control”, Electro–Technology, June, 1969. P.J. Ottowitz, “A Guide to Crystal Selection”, Electronic Design, May, 1966. LEGACY APPLICATIONS The features of the ML145145 permit bus operation with a dedicated wire needed only for the strobe input. In a micro- Page 9 of 12 processor–controlled system this strobe input is accessed when the PLL is addressed. The remaining data and address inputs will directly interface to the microprocessor’s data and address buses. The ÷ R programability is used to advantage in Figure 10. Here, the nominal ÷ R value is 3667, but by programming small changes in this value, fine tuning is accomplised. Better tuning resolution is achievable with this method than by changing the ÷ N due to the use of the large fixed prescaling value of ÷ 256 provided by the ML12079. The two–loop synthesizer, in Figure 11, takes advantage of these features to control the phase–locked loop with a minumum of dedicated lines while preserving optimal loop performance. Both 25 Hz and 100 Hz steps are provided while the relatively large reference frequencies of 10 Khz or 10.1 kHz are maintained. www.lansdale.com Issue b ML145145 Page 10 of 12 LANSDALE Semiconductor, Inc. www.lansdale.com Issue b ML145145 Page 11 of 12 LANSDALE Semiconductor, Inc. www.lansdale.com Issue b ML145145 LANSDALE Semiconductor, Inc. OUTLINE DIMENSIONS P DIP 18 = VP (ML145145VP) CASE 707–02 18 NOTES: 1. POSITIONAL TOLERANCE OF LEADS (D), SHALL BE WITHIN 0.25 (0.010) AT MAXIMUM MATERIAL CONDITION, IN RELATION TO SEATING PLANE AND EACH OTHER. 2. DIMENSION L TO CENTER OF LEADS WHEN FORMED PARALLEL. 3. DIMENSION B DOES NOT INCLUDE MOLD FLASH. 10 B 1 9 A L C K N F H D J M SEATING PLANE G DIM A B C D F G H J K L M N SOG 20W = -6P (ML145145-6P) CASE 751D–04 –A– 20 10X P 0.010 (0.25) 1 M B M 10 20X D 0.010 (0.25) M T A B S J S F R C –T– 18X G K SEATING PLANE INCHES MIN MAX 0.875 0.915 0.240 0.260 0.140 0.180 0.014 0.022 0.050 0.070 0.100 BSC 0.040 0.060 0.008 0.012 0.115 0.135 0.300 BSC 0° 15° 0.020 0.040 NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.150 (0.006) PER SIDE. 5. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOW ABLE DAMBAR PROTRUSION SHALL BE 0.13 (0.005) TOTAL IN EXCESS OF D DIMENSION AT MAXIMUM MATERIAL CONDITION. 11 –B– MILLIMETERS MIN MAX 22.22 23.24 6.10 6.60 3.56 4.57 0.36 0.56 1.27 1.78 2.54 BSC 1.02 1.52 0.20 0.30 2.92 3.43 7.62 BSC 0° 15° 0.51 1.02 X 45° DIM A B C D F G J K M P R MILLIMETERS MIN MAX 12.65 12.95 7.40 7.60 2.35 2.65 0.35 0.49 0.50 0.90 1.27 BSC 0.25 0.32 0.10 0.25 0° 7° 10.05 10.55 0.25 0.75 INCHES MIN MAX 0.499 0.510 0.292 0.299 0.093 0.104 0.014 0.019 0.020 0.035 0.050 BSC 0.010 0.012 0.004 0.009 0° 7° 0.395 0.415 0.010 0.029 M Lansdale Semiconductor reserves the right to make changes without further notice to any products herein to improve reliability, function or design. Lansdale does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. “Typical” parameters which may be provided in Lansdale data sheets and/or specifications can vary in different applications, and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by the customer’s technical experts. Lansdale Semiconductor is a registered trademark of Lansdale Semiconductor, Inc. Page 12 of 12 www.lansdale.com Issue b