ML13135 FM Communications Receiver; Dual Conversion Narrowband FM Receiver

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1 F Communications Receiver; Dual Conversion Narrowband F Receiver Legacy Device: otorola C The L is the second generation of single chip, dual conversion F communications receivers developed by otorola. ajor improvements in signal handling, RSSI and first oscillator operation have been made. In addition, recovered audio distortion and audio drive have improved. These receivers offer low noise, high gain and stability over a wide operating voltage range, and Lansdale is pleased to continue to offer them. The L includes a Colpitts oscillator, VCO tuning diode, low noise first and second mixer and LO, high gain limiting IF, and RSSI. The L is designed for use with an LC quadrature detector and has an uncommitted op amp that can be used either for an RSSI buffer or as a data comparator. This device can be used as a stand alone VHF receiver or as the lower IF of a triple conversion system. Applications include cordless telephones, short range data links, walkie talkies, low cost land mobile, amateur radio receivers, baby monitors and scanners. OPERATING FEATURES P DIP = LP PLASTIC PACKAGE CASE SO = -P CASE E (SO L) CROSS REFERENCE/ORDERING INFORATION PACKAGE OTOROLA LANSDALE P DIP CP LLP SO CDW L-P Note: Lansdale lead free (Pb) product, as it becomes available, will be identified by a part number prefix change from L to LE. Complete Dual Conversion F Receiver Antenna to Audio Output Input Frequency Range Hz Voltage Buffered RSSI with db of Usable Range Low Voltage Operation. to. Vdc ( Cell NiCad Supply) Low Current Drain. ma Typ Low Impedance Audio Output < Ω VHF Colpitts First LO for Crystal or VCO Operation Isolated Tuning Diode Buffered First LO Output to Drive COS PLL Synthesizer Operating Temperature Range TA = to 8 C st LO Base st LO Emitter st LO Out nd LO Emitter nd LO Base PIN CONNECTIONS st LO Varicap nd LO 9 Varicap C Varicap A st ixer In st ixer In st ixer Out nd ixer Out VEE 8 AF 8 nd ixer In Audio Out Limiter In Decouple 9 Limiter Demod Op Amp Out Op Amp In Decouple Op Amp In RSSI Quad Coil The device contains active transistors. Page of

2 AXIU RATINGS Rating Pin Symbol Value Unit Power Supply Voltage, 9 (max). Vdc RF Input Voltage RFin. Vrms Junction Temperature TJ C Storage Temperature Range Tstg to C RECOENDED OPERATING CONDITIONS Rating Pin Symbol Value Unit Power Supply Voltage, 9. to. Vdc aximum st IF fif Hz aximum nd IF fif. Hz Ambient Temperature Range TA to 8 C ELECTRICAL CHARACTERISTICS (TA = C, =. Vdc, fo = 9. Hz, fod =. khz, Deviation = ±. khz, fstlo = 9 Hz, fnd LO =. Hz, IF =. Hz, IF =, unless otherwise noted. All measurements performed in the test circuit of Figure.) Characteristic Condition Symbol in Typ ax Unit Total Drain Current No Input Signal ICC.. madc Sensitivity (Input for db SINAD) atched Input VSIN. µvrms Recovered Audio VRF =. mv AFO mvrms st ixer Conversion Gain VRF = dbm Xgain db nd ixer Conversion Gain VRF = dbm Xgain db First LO Buffered Output VLO mvrms Total Harmonic Distortion VRF = dbm THD.. % Demodulator Bandwidth BW khz RSSI Dynamic Range RSSI db First ixer rd Order Intercept TOIix dbm (Input) atched Unmatched Second ixer rd Order atched TOIix dbm Intercept (RF Input) Input First LO Buffer Output Resistance RLO Ω First ixer Parallel Input Resistance R Ω First ixer Parallel Input Capacitance C. pf First ixer Output Impedance ZO Ω Second ixer Input Impedance ZI. kω Second ixer Output Impedance ZO.8 kω Detector Output Impedance ZO Ω Page of

3 TEST CIRCUIT INFORATION The recovered audio measurements for the L are made with an LC quadrature detector. The typical recovered audio will depend on the external circuit; either the Q of the quad coil, or the RC matching network for the ceramic discriminator. See Figures and for additional information. Since adding a matching circuit to the RF input increases the signal level to the mixer, the third order intercept (TOI) point is better with an unmatched input ( Ω from Pin to Pin ). Typical values for both have been included in the Electrical Characterization Table. TOI measurements were taken at the pins with a high impedance probe/spectrum analyzer system. The first mixer input impedance was measured at the pin with a network analyzer. Figure a. L Test Circuit. k.8 µh 9. Hz Xtal. k p p. p p st LO nd LO Varicap 9.. µh. Hz Figure. pf 8 p RF Input. Hz Xtal 8 9 Limiter Demod AF 8 8. k 9 k 9 k Quad Coil Page of

4 Figure. Supply Current versus Supply Voltage. Figure. RSSI Output versus RF Input I C C, SUPPLY CURRENT (ma )..... RFin = 9. Hz fod =. khz fdev = ±. khz RSSI OUTPUT (mvdc, Pin ) 8 =. V RFin = 9. Hz fod =. khz fdev = ±. khz , SUPPLY VOLTAGE (V) 8 RF INPUT (dbm) C P, EQUIVALENT PARALLEL CAPACITANCE (pf ).. Figure. Varactor Capacitance, Resistance versus Bias Voltage CP, f = Hz CP, f = Hz RP, f = Hz RP, f = Hz VB, VARACTOR BIAS VOLTAGE, VPin to VPin (Vdc) R P, EQUIVALENT PARALLEL RESISTANCE (k Ω ) f, FREQUENCY (Hz) Figure. Oscillator Frequency versus Varactor Bias p p. p st LO Varicap..... VB, VARACTOR BIAS VOLTAGE (Vdc). µh p. Ω. µf V B POWER (dbm) Figure. Signal Levels versus RF Input Second ixer Output First ixer Output First ixer Input Second ixer Input 9 8 RFin, RF INPUT (dbm) SN, N, AND AR (db) Figure. Signal Noise, Noise, and A Rejection versus Input Power =. Vdc RFin = 9. Hz fod =. khz fdev = ±. khz 9 RFin, RF INPUT (dbm) S N S N % A N Page of

5 Figure 8. Op Amp Gain and Phase versus Frequency 8 Figure 9. First ixer Third Order Intermodulation (Unmatched Input) A V, GAIN (db ) Gain Phase,φ EXCESS PHASE (DEGREES) IXER OUTPUT (db) 8 Desired Products rd Order Intermod Products k k. f, FREQUENCY (Hz) 8 8 RF INPUT (dbm) pp ) RA, RECOVERED AUDIO (mv ±. Figure. Recovered Audio versus Deviation for L R Quad Coil Toko C 88Z fdev, DEVIATION (khz) R = 8 kω R = kω R = 9 kω ±. ±. ±. ± 9. TOTAL HARONIC DISTORTION (%) THD, R Figure. Distortion versus Deviation for L Quad Coil Toko C 88Z. R = 9 kω. ±. ±. ±. ±. ± 9. fdev, DEVIATION (khz) R = 8 kω R = kω Page of

6 CIRCUIT DESCRIPTION The L is a complete dual conversion receiver. This includes two local oscillators, two mixers, a limiting IF amplifier and detector, and an op amp. It will provide a voltage buffered RSSI with db of usable range, isolated tuning diode and buffered LO output for PLL operation, and a separate pin for the first mixer and LO. Improvements have been made in the temperature performance of both the recovered audio and the RSSI. Two separate V CC lines enable the first LO and mixer to continue running while the rest of the circuit is powered down. They also isolate the RF from the rest of the internal circuit. Local Oscillators The local oscillators are grounded collector Colpitts, which can be easily crystal controlled or VCO controlled with the on board varactor and external PLL. The first LO transistor is internally biased, but the emitter is pinned out and IQ can be increased for high frequency or VCO operation. The collector is not pinned out, so for crystal operation, the LO is generally limited to rd overtone crystal frequencies; typically around Hz. For higher frequency operation, the LO can be provided externally as shown in Figure. Buffer An amplifier on the st LO output converts the single ended LO output to a differential signal to drive the mixer. Capacitive coupling between the LO and the amplifier minimizes the effects of the change in oscillator current on the mixer. Buffered LO output is pinned out at Pin for use with a PLL, with a typical output voltage of mvpp at =. V and with a. k resistor from Pin to ground. As seen in Figure, the buffered LO output varies with the supply voltage and a smaller external resistor may be needed for low voltage operation. The LO buffer operates up to Hz, typically. Above Hz, the output at Pin rolls off at approximately. db per octave. Since most PLLs require about mvpp drive, an external amplifier may be required. ixers The first and second mixer are of similar design. Both are double balanced to suppress the LO and input frequencies to give only the sum and difference frequencies out. This configuration typically provides to db of LO suppression. New design techniques provide improved mixer linearity and third order intercept without increased noise. The gain on the output of the st mixer starts to roll off at about Hz, so this receiver could be used with a Hz first IF. It is designed for use with a ceramic filter, with an output impedance of Ω. A series resistor can be used to raise the impedance for use with a crystal filter, which typically has an input impedance of. kω. The second mixer input impedance is approximately. kω; it requires an external Ω parallel resistor for use with a standard ceramic filter. Limiting IF Amplifier and Detector The limiter has approximately db of gain, which starts rolling off at. Hz. Although not designed for wideband operation, the bandwidth of the audio frequency amplifier has been widened to khz, which gives less phase shift and enables the receiver to run at higher data rates. However, care should be taken not to exceed the bandwidth allowed by local regulations. The L is designed for use with an LC quadrature detector, and does not have sufficient drive to be used with a ceramic discriminator. The discriminators and the external matching circuit will affect the distortion and recovered audio. RSSI/Op Amp The Received Signal Strength Indicator (RSSI) on the L has about db of range. The resistor needed to translate the RSSI current to a voltage output has been included on the internal circuit, which gives it a tighter tolerance. A temperature compensated reference current also improves the RSSI accuracy over temperature. On the L, the op amp is not connected internally and can be used for the RSSI or as a data slicer (see Figure c). Figure. Buffered LO Output Voltage versus Supply Voltage RPin =. kω O UTPUT (mv p p ) RPin =. kω , SUPPLY VOLTAGE (Vdc) Page of

7 Figure. PLL Controlled Narrowband F Receiver at /9 Hz L OSC Out OSC In VDD Fin D PD D PD D LD D VSS Fin L8. k k.. p k.8 µh. Hz Xtal p p p p. p. k p 8 9 st LO nd LO Limiter Varicap AF Demod k. µh. Hz k pf pf RF Input Recovered Audio RSSI Output 8 k Quad Coil Figure. Hz Single Channel Application Circuit st LO External Oscillator Circuit Preamp for L at. Hz.8 µ. k k p. k X 8 p p L Q. µf p p fosc =. Hz Q PS9 X.8 Hz rd Overtone Series Resonant Crystal L.8 µh Inductor (Coilcraft Part # J8) RF Input p p p L. k p k. µ L Q 9 p. µf p To ixer Q PS9 L. µh L. µh Page of

8 Legacy Applications Information Figure a. Single Channel Narrowband F Receiver at 9. Hz Buffered LO Output.. k. µh p p 9 Hz Xtal. p p. k p st LO nd LO L Varicap 9.. µh. Hz Figure. pf p RF Input Ω Source. Hz Xtal 8 9 Limiter Demod 8 AF. k k Recovered Audio RSSI Output 9 k Quad Coil Figure b. PC Board Component View.k p p p p. Hz XT CF p KHz 9 Hz XT. k C.. Hz CF p p.k k. NOTES:.. µh tunable (unshielded) inductor. 9 Hz Series mode resonant rd Overtone Crystal.. µh tunable (shielded) inductor.. Hz Fundamental mode crystal, pf load. ceramic filter, murata CFU B or equivalent. Quadrature coil, Toko C 88Z (mm) or Toko RC A9H (mm).. Hz ceramic filter, murata SFE.J A or equivalent.. 9K K k C9 Figure c. Optional Data Slicer Circuit (Using Internal Op Amp) Vin (Pin ) k k. k k FSK Data Output. Page 8 of

9 Legacy Applications Information Figure 8. PC Board Solder Side View RF IN L.O. A UDIO V CC GROUN D. SPEAKER RSSI C C. (Circuit Side View) Figure 9. PC Board Component View.k p p p p. Hz XT CF p KHz 9 Hz XT. k C.. Hz CF p k p.k. NOTES:.. µh tunable (unshielded) inductor. 9 Hz Series mode resonant rd Overtone Crystal.. µh tunable (shielded) inductor.. Hz Fundamental mode crystal, pf load. ceramic filter, murata CFU B or equivalent. discriminator, murata CDBC or equivalent.. Hz ceramic filter, murata SFE.J A or equivalent p...k k K C9 Page 9 of

10 8 Schematic L Internal Figure. V C C V C C. k. k. k 8. k k k. k. k. k. p F irst LO First ixer Second LO Second ixe r V C C V C C Figure. k Op Amp V C C V C C Bias. p 9 k k. k L imiting IF Amplifier Detector and Audio Amplifie r active transistors. device contains This Page of

11 OUTLINE DIENSIONS P DIP = LP PLASTIC PACKAGE (LLP) CASE ISSUE D A B NOTES:. CHAFERED CONTOUR OPTIONAL.. DIENSION L TO CENTER OF LEADS WHEN FORED PARALLEL.. DIENSIONING AND TOLERANCING PER ANSI Y., 98.. CONTROLLING DIENSION: INCH. T SEATING PLANE G E F D PL N K C. (.) T A L J PL NOTE. (.) T B DI A B C D E F G J K L N INCHES IN AX BSC.. BSC.. BSC.. ILLIETERS IN AX BSC... BSC BSC.. T SEATING PLANE A D PL. (.) T A S B S G PL B C K SO = -P (L-P) PLASTIC PACKAGE CASE E ISSUE E P PL. (.) B J F R X NOTES:. DIENSIONING AND TOLERANCING PER ANSI Y., 98.. CONTROLLING DIENSION: ILLIETER.. DIENSIONS A AND B DO NOT INCLUDE OLD PROTRUSION.. AXIU OLD PROTRUSION (.) PER SIDE.. DIENSION D DOES NOT INCLUDE DABAR PROTRUSION. ALLOWABLE DABAR PROTRUSION SHALL BE (.) TOTAL IN EXCESS OF D DIENSION AT AXIU ATERIAL CONDITION. DI A B C D F G J K P R ILLIETERS IN AX BSC. BSC INCHES IN AX 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 of

PIN CONNECTIONS. 1st LO Base. Varicap C. 1st LO Emitter. Varicap A. 1st LO Out. 1st Mixer In 1. 1st Mixer In 2. 2nd LO Emitter.

PIN CONNECTIONS. 1st LO Base. Varicap C. 1st LO Emitter. Varicap A. 1st LO Out. 1st Mixer In 1. 1st Mixer In 2. 2nd LO Emitter. Order this document by MC/D The MC/MC are the second generation of single chip, dual conversion FM communications receivers developed by Motorola. Major improvements in signal handling, RSSI and first