NJM2537 FM IF IC FOR PAGERS GENERAL DESCRIPTION PACKAGE OUTLINE The NJM2537 is a low power FM IF IC for pagers. It is capable of designing dual conversion pager system because of including a mixer circuit. Also it includes RSSI function, so that it is easy to design automatic gain control (AGC) which improves interberence when strong signal is received. NJM2537V FEATURES Low Operating Voltage 1.1 to 4.0V + Low Operating Current 1.2mA typ.at V =1.4V RF Input Frequency 10 to 50MHz 2nd Mixer Package Outline SSOP20 PIN FUNCTION AND BLOCK DIAGRAM 1. OSC IN 11. LPF IN 2. OSC OUT 12. LPF OUT 3. MIXER OUT 13. BS + 4. V 14. CHARGE 5. IF IN 15. FSK OUT 6. DECOUPLING 16. VALM 7. FSK REF 17. REG CONT 8. QUAD IN 18. REG OUT 9 AF OUT 19. GND 10. RSSI 20. MIXER IN Ver.2003-12-09 -1- NJM2537 ABSOLUTE MAXIMUM RATINGS (T =25C) a PARAMETER SYMBOL RATINGS UNIT Supply voltage V 4.0 V CC Power Dissipation P 300 mW D Operating Temperature Range T -30 to +85 C opr Storange Temperature Range T -40 to +125 C stg + ELECTRICAL CHARACTERISTICS (V =1.4V, f =21.7MHz, fIF=455kHz, fmod=600Hz, fdev=4kHz, T =25C) C a PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT No Signal Operating Current I - 1.2 1.5 mA CCq Battery Saving I - 0 5 A CCS Operating Current Mixer Gain GMIX After Ceramic Filter 11 14.5 18 dB Mixer Intercept Point IP - 103 - dBVEMF Mixer Input Resistance RMIX - 5 - k in Mixer Output Resistance RMIX - 2 - k O IF Amplifier Input Resistance RIF - 2 - k in S / N 1 S / N 1 MIXER Input, V=60dBVEMF - 63 - dB I S / N 2 S / N 2 IF Input, V=60dBVEMF - 63 - dB I S / N 3 S / N 3 IF Input, V=22dBVEMF - 25 - dB I -3dB Limiting Sensitivity 1 LIM1 MIXER Input - 12 17 dBVEMF -3dB Limiting Sensitivity 2 LIM2 IF Input - 22 27 dBVEMF Demodulated Output Level Vod IF Input, VI=60dBVEMF 30 46 65 mVrms AM Rejection Ratio AMR IF Input, V=60dBVEMF, AM=30% - 50 - dB I Duty Ratio at Wave Shaped Output DR IF Input, V=60dBVEMF 40 50 60 % I RSSI Output Voltage V IF Input, V=65dBVEMF 0.48 0.62 0.76 V rssi I RSSI Output Resistance R - 62 - k rssi Quick Charge / Discharge Current I GND, 0.18V 40 70 115 A ch Alarm Detection Voltage Valm 1.05 1.10 1.15 V Regulator Output Voltage Vreg RL=430 0.95 1.00 1.05 V Low level Output Voltage ValmL IL=100A - 0.1 0.4 V of VALM Terminal High Level Leak Current IalmH - 0 2 A of VALM Terminal Low Level Output Voltage VfskL IL=100A - 0.1 0.4 V of FSK-OUT Terminal High Level Leak Current IfskH - 0 2 A of FSK-OUT Terminal Low Level Output Voltage VregL IL=100A - - 0.6 V of REG-OUT Terminal Ver.2003-12-09 - 2 -