FM IF RECEIVER S1T8513A INTRODUCTION 20−SSOP−225 The S1T8513A is designed for FM IF Detection on the pager set. It includes a voltage regulator, low battery detection circuit, Mixer, Oscillator, FSK comparator and limiting IF Amplifier. FEATURES • Operating voltage range: 1.0 ~ 4.0V • Typical supply current: 1.1mA at 1.4V • Low battery detection circuit (alarm function): 1.05V • Voltage regulator : Vreg = 1.0V (Typ.) • Mixer operating frequency: 10 ~ 50MHz • High transmitting rate: 1200 / 2400bps • FSK Data reception • Package type: 20-SSOP (0.65mm) ORDERING INFORMATION Device Package Operating Temperature S1T8513A02-V0B0 20-SSOP-225 −20°C to +70°C BLOCK DIAGRAM MI 20 GND 19 REGO REGC 18 17 AO 16 FSKO 15 14 1.0V Reg 2’nd MIX QC FSK COMP. BSC 13 Quick Charge LPFO 12 1 OSCI 11 filter AMP Alarm audio AMP Limiting IF Amplifier X-tal Osc LPFI Quad Detector 2 3 4 5 6 OSCO MO Vcc LI LD 7 FSKI 8 9 IFO QD 10 RAO 1 S1T8513A FM IF RECEIVER PIN CONFIGURATION 2 OSCI 1 20 MI OSCO 2 19 GND MO 3 `18 REGO Vcc 4 17 REGC LI 5 16 AO LD 6 15 FSKO FSKI 7 14 QC IFO 8 13 BSC QD 9 12 LPFO RAO 10 11 LPFI KA8513B S1T8513A FM IF RECEIVER S1T8513A PIN DESCRIPTION Pin No Symbol Description 1 OSCI Oscillator input. The oscillator is an internally-biased colpitts type. 2 OSCO Oscillator output. 3 MO Mixer output pin. Output impedance ≈ 2kΩ. Connect a 455kHz filter between this pin and the LI. 4 VCC VCC pin. 5 LI IF limiter amplifier input. Input impedance 2kΩ. 6 LD Bypass capacitor connect pin for the IF limiter amplifier. 7 FSK1 8 IFO IF Amp output. 9 QD Quadrature detection, phase shiftier pin. 10 RAO Recovered audio signal output. 11 LPFI Low pass filter amplifier input. Bias is supplied from pin 10. 12 LPFO Low pass filter amplifier output. 13 BSC Battery saving control pin. High: Battery saving off. Low: Battery saving on 14 QC Quick charge control pin. High: Quick charge-discharge on. Low: Quick charge-discharge off. 15 FSKO 16 AO 17 REGC S1T8513A has an internal PNP transistor. But, it also can support an external PNP transistor to control the power. 18 REGO Regulated voltage output. 19 GND 20 MI Differential Amp. reference input on the FSK comparator. FSK signal output pin. Alarm output. This pin becomes High when VCC drops below 1.05V. Ground. Mixer input impedance ≈ 5kΩ. ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Value Unit VCC (MAX) 4 V PD 800 mW Operating Temperature TOPR −20 — +70 °C Storage Temperature TSTG −55 — +125 °C Max. Supply Voltage Power Dissipation 3 S1T8513A FM IF RECEIVER ELECTRICAL CHARACTERISTICS (VCC = 1.4V ±5%, fIN (2MIX) = 21.4MHz, fDEV = ±4.8kHz, fMOD = 600Hz, Ta = 25°C, unless otherwise specified) Characteristic Symbol Test Conditions Min. Typ. Max. Unit ICCN No Input Signal − 1.1 1.6 mA ICCS Battery Saving − 0 10 µA Alarm Detection Voltage VAD − 1.0 1.05 1.1 V Alarm Low Level Output Voltage VO (AL) − − 0.4 V Alarm High Level Leakage Current ILKG (AL) − − 2 µA FSK Low Level Output Voltage VL (FSK) − − 0.4 V FSK High Level Leakage Current ILKG (FSK) − − − 2 µA Regulator Output Voltage VO (REG) − 0.95 1.0 1.05 V Quick Charge Current IC − 50 70 − µA Input for −3dB Sensitivity VLIM Mixer Input − 2.5 7.5 µVrms Input for −12dB SINAD Sensitivity VI (SEN) IF Input − 6.0 18.0 µVrms Recovered Audio Output Voltage VO (RAO) VIN (2MIX) = 500µVrms 37 55 73 mVrms Mixer Conversion Voltage Gain ∆GV (M) Ceramic Filter loss = −1dB 8 12 16 dB Signal to Noise Ratio S/N VIN (2MIX) = 500µVrms 38 55 − dB Total Harmonic Distortion THD VIN (2MIX) = 500µVrms − 2.0 3.5 % Mixer 3rd Order Intercept Point 3RD − − −10 − dBm Mixer Input Resistance RI (MIX) − 3.5 5 6.5 kΩ Limiting Amplifier Input Resistance RI (LA) − 1.4 2 2.6 kΩ AM Rejection Ratio AMR VIN (2MIX) = 5µVrms (AM = 300%) 25 40 − dB Data Shaping Output Duty Ratio DR VIN (2MIX) = 500µVrms 40 50 60 % Operating current 4 I = 100µA − I = 100µA FM IF RECEIVER S1T8513A APPLICATION CIRCUIT Alarm out FSK out Reg.out VCC + 100K 2.2µ 100K 68K R9 L H H 51 L 100P MI 20 68K 0.01µ GND 19 REGO 18 REGC 17 AO 16 FSKO 15 QC 14 1.0V Regulator BSC 13 LPFO 12 Quick Charge 2’ndn 2’ d MIX MAX AMP COMP AMP 68K Audio Limiting IF Amplifier X-tal Osc 1 2 OSCI 3 OSCO 4 MO C3 5 Vcc 7 IF DEC 8 FSKI 9 IFO C4 33P CFMW455E 10 QD RAO C9 0.1µ 56P 20.945MHz Quad Detector 6 IFI 3.3n 560P 11 Filter FSK Alarm LPFI + 10µ R2 22P CDBM455 Vcc 3.3K + 10µ 5 S1T8513A FM IF RECEIVER NOTES 6