NJM2537V

NJM2537 FM IF IC FOR PAGERS ■ GENERAL DESCRIPTION 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. ■PACKAGE OUTLINE NJM2537V ■ FEATURES ● Low Operating Voltage ● Low Operating Current ● RF Input Frequency ● 2nd Mixer ● Package Outline 1.1 to 4.0V 1.2mA typ.at V+=1.4V 10 to 50MHz SSOP20 ■ PIN FUNCTION AND BLOCK DIAGRAM 1. 2. 3. 4. 5. 6. 7. 8. 9 10. OSC IN OSC OUT MIXER OUT V+ IF IN DECOUPLING FSK REF QUAD IN AF OUT RSSI 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. LPF IN LPF OUT BS CHARGE FSK OUT VALM REG CONT REG OUT GND MIXER IN Ver.2003-12-09 -1- NJM2537 ■ ABSOLUTE MAXIMUM RATINGS PARAMETER Supply voltage Power Dissipation Operating Temperature Range Storange Temperature Range SYMBOL VCC PD Topr Tstg RATINGS 4.0 300 -30 to +85 -40 to +125 (Ta=25°C) UNIT V mW °C °C ■ ELECTRICAL CHARACTERISTICS PARAMETER No Signal Operating Current Battery Saving Operating Current Mixer Gain Mixer Intercept Point Mixer Input Resistance Mixer Output Resistance IF Amplifier Input Resistance S/N1 S/N2 S/N3 -3dB Limiting Sensitivity 1 -3dB Limiting Sensitivity 2 Demodulated Output Level AM Rejection Ratio Duty Ratio at Wave Shaped Output RSSI Output Voltage RSSI Output Resistance Quick Charge / Discharge Current Alarm Detection Voltage Regulator Output Voltage Low level Output Voltage of VALM Terminal High Level Leak Current of VALM Terminal Low Level Output Voltage of FSK-OUT Terminal High Level Leak Current of FSK-OUT Terminal Low Level Output Voltage of REG-OUT Terminal SYMBOL ICCq ICCS GMIX IP RinMIX ROMIX RinIF S/N1 S/N2 S/N3 LIM1 LIM2 Vod AMR DR Vrssi Rrssi Ich Valm Vreg ValmL IalmH VfskL IfskH VregL (V+=1.4V, fC=21.7MHz, fIF=455kHz, fmod=600Hz, fdev=±4kHz, Ta=25°C) TEST CONDITION MIN. After Ceramic Filter 11 MIXER Input, VI=60dBµVEMF IF Input, VI=60dBµVEMF IF Input, VI=22dBµVEMF MIXER Input IF Input IF Input, VI=60dBµVEMF IF Input, VI=60dBµVEMF, AM=30% IF Input, VI=60dBµVEMF IF Input, VI=65dBµVEMF GND, 0.18V RL=430Ω IL=100µA 30 40 0.48 40 1.05 0.95 IL=100µA IL=100µA TYP. 1.2 0 14.5 103 5 2 2 63 63 25 12 22 46 50 50 0.62 62 70 1.10 1.00 0.1 0 0.1 0 MAX. 1.5 5 18 17 27 65 60 0.76 115 1.15 1.05 0.4 2 0.4 2 0.6 UNIT mA µA dB dBµVEMF kΩ kΩ kΩ dB dB dB dBµVEMF dBµVEMF mVrms dB % V kΩ µA V V V µA V µA V -2- Ver.2003-12-09 NJM2537 ■ APPLICATION CIRCUIT Ver.2003-12-09 -3- NJM2537 ■ TERMINAL FUNCTION PIN NO. SYMBOL PIN VOLTAGE (V) FUNCTION Local Oscillator Input. In case of using a crystal oscillator, it is connected. EQUIVALENT CIRCUIT 1 OSC IN 1.38 2 OSC OUT 0,68 Local Oscillator Output. In case of using an external oscillator, the external clock is input. Mixer input. Input resistance is 5kΩ typical. 20 MIX IN 0.8 Mixer output. Output resistance is 2kΩ typical. 3 MIX OUT 0.7 5 IF IN 1.38 Limiter amplifier input. Input resistance is 2kΩ typical. Decoupling for bias. 6 DEC 1.38 8 QUAD IN 1.4 Input of quadrature detection circuit. A ceramic discriminator is connected. Demodulated signal Output. 9 AF OUT 0.16 -4- Ver.2003-12-09 NJM2537 ■ TERMINAL FUNCTION PIN NO. SYMBOL PIN VOLTAGE (V) FUNCTION RSSI output EQUIVALENT CIRCUIT 10 RSSI 0 Input of a low pass filter. It is biased from AF-OUT (9pin) through an external RC filter. 11 LPF IN 0.18 Output of a low pass filrter. 12 LPF OUT 0.18 7 FSK REF 0.18 Reference input of a wave shaping comparator. An external capacitor is connected. 13 BS - Control of a battery saving circuit. Hi : active Lo : suspended 14 CHARGE - Control of a quick charge / discharge circuit. Hi : Its circuit turns ON Lo : Its circuit turns OFF 15 FSK OUT - Output of a wave shaping circuit. The output signal is inverted against LPF output signal. Ver.2003-12-09 -5- NJM2537 ■ TERMINAL FUNCTION PIN NO. SYMBOL PIN VOLTAGE (V) FUNCTION Output of the alarm signal. + When V drops down to 1.1V, this output becomes high. 16 VALM 0.1 EQUIVALENT CIRCUIT Control of an external PNP transistor used for the regulator. 17 REG CONT 0.6 Monitoring of the regulator. 18 REG OUT 1.0 4 19 V + - Power Supply Ground - GND -6- Ver.2003-12-09 NJM2537 ■ TYPICAL CHARACTERISTICS S+N N, AMR vs. Mixer Input  V + = 1.4 V, fRF = 21.7MHz, fLO = 22.155MHz    VLO = 110dBuV, fdev = ±4kHz, f mod = 600Hz     S+N, N, AMR vs. IF Input (V+=1.4V, fIF=455kHz, fdev=±4kHz, fmod=600Hz) Mixer Gain vs. Supply Voltage (fin=21.7MHz, VRF=60dBuV, fLO=22.155MHz, VLO=110dBu) Operating Current vs. Supply Voltage (No Signal) RSSI vs. Supply Voltage (VIF=65dBuVEMF, fIF=455kHz) Demodulated Output vs. Supply Voltage (Vin=60dBuVEMF, fIF=455kHz, fmod=600Hz) Ver.2003-12-09 -7- NJM2537 ■ TYPICAL CHARACTERISTICS Quick Charge Current vs. Supply Current (12pin=0.18V) Operating Current vs. Temperature (V+=1.4V) Battery Saving Operating Current vs. Temperature (V+=1.4V) Quick Charge Current vs. Temperature (V+=1.4V, 12pin=0.18V) Mixer Gain vs. Temperature (V =1.4V, fRF=21.7MHz, Vin=60dBµV) + Demodulated Output vs. Temperature (V =1.4V, fIF=455kHz, Vin=60dBµVEMF, fmod=600Hz) + -8- Ver.2003-12-09 NJM2537 ■ TYPICAL CHARACTERISTICS RSSI vs. Temperature  V + = 1.4 V, fRF21.7MHz, VRF = 50dBuVEMF,    fLO = 22.155MHz, VLO = 110dBuV, mod = OFF     -3dB Limiting Sensitivity vs. Temperature (V+=1.4V, Mixer input, fRF=21.7MHz, fmod=600Hz) Mixer Output vs. RF Input (V+=1.4V, fRF=21.7MHz, fLO=22.155MHz, VLO=110dBuV) Mixer Gain vs. Local Oscillation  V + = 1.4V, fRF = 21.7MHz, VRF = 60dBuV,    fLO = 22.155MHz, V = 60dBuV  in   Mixer Gain vs. Frequency (V+=1.4V, VRF=60dBuV, VLO=110dBuV, fLO=fRF+455kHz) RSSI vs. IF Input (V+=1.4V, fIF=455kHz) Ver.2003-12-09 -9- NJM2537 [CAUTION] The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. - 10 - Ver.2003-12-09