LOW VOLTAGE/POWER NARROW BAND FM IF INTRODUCTION S1T3361D 16−DIP−300A The S1T3361D is designed for use in FM dual conversion communication. It contains a complete narrow band FM demodulation system operable to less than 2.5V supply voltage. This low-power narrow-band FM IF system provides the second converter, second IF, demodulator. Filter Amp and squelch circuitry for communications and scanning receivers. 16−SOP−225A FEATURES • Low power consumption (4.0mA typ. at VCC = 4.0V) • Excellent input sensitivity (-3dB limiting, 2.0µVrms typ.) • Minimum number of external components required. • Operating Voltage: 2.5 to 7.0V APPLICATIONS • Cordless phone (for home usage) • FM dual conversion communications equipment ORDERING INFORMATION Device Package S1T3361D01-D0B0 16−DIP−300A S1T3361D01-S0B0 16−SOP−225A Operating Temperature − 20°C to +70°C 1 S1T3361D LOW VOLTAGE/POWER NARROW BAND FM IF PIN CONFIGURATION OSC 1 16 RF INPUT OSC 2 15 GND MIXER OUTPUT 3 14 MUTE VCC 4 13 SCAN CONTROL S1T3361D LIMITER INPUT 5 12 SQUELCH INPUT DECOUPLING 6 11 FILTER OUTPUT DECOUPLING 7 10 FILTER INPUT QUADRATURE INPUT 8 9 AUDIO OUTPUT ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Value Unit VCC (MAX) 10 V Supply Voltage Range VCC 2.5 to 7.0 V Detector Input Voltage VI (DET) 1.0 VP-P RF Input Voltage (VCC ≥ 4.0V) VI (RF) 1.0 Vrms Mute Function VMUTE − 0.5 to + 0.5 Vpeak Operating Temperature TOPR − 20 to + 70 °C Storage Temperature TSTG − 65 to + 150 °C Max. Supply Voltage NOTE: Absolute maximum ratings are those values beyond which permanent damage to the device may occur. These are stress ratings only and functional operation of the device at or beyond them is not implied. Long exposure to these conditions may affect device reliability. 2 LOW VOLTAGE/POWER NARROW BAND FM IF S1T3361D ELECTRICAL CHARACTERISTICS (VCC = 4.0V, fo = 10.7MHz, ∆f = ± 3kHz, fMOD = 1kHz, Ta = 25°C, unless otherwise specified) Characteristic Operating Current Symbol ICC Test Conditions Min. Typ. Max. Unit Squelch off (V12 = 2V) 2.0 3.0 4.0 6.0 8.0 10 mA mA -3.0dB limiting − 2.0 6.0 µV Squelch on (V12 = GND) Input Limiting Voltage VI (LIM) Detector Output Voltage VO (DET) − − 2.0 − Vdc Detector Output Impedance ZO (DET) − − 400 − W Recoverd audio output voltage VO Vin = 10mV 134 150 168 mVrms Filter Gain GV f = 10kHz, Vin = 5mV 40 48 52 dB VO (DC) − 1.0 1.5 2.0 Vdc Trigger Hysteresis of Filter VTH − − 50 − mV Mute Switch-on Resistance RON (MUTE) Mute Low − 10 40 Ω Mute Switch-off Resistance ROFF(MUTE) Mute High 1 - 10 MΩ − − 0.5 Vdc 3.0 − − Vdc Filter Output DC Voltage Scan Control Low Output VL (SCAN) Mute off (V12 = 2V) Scan Control High Output VH (SCAN) Mute on (V12 = GND) Mixer Conversion Gain GV (MIXER) − 30 36 − dB Mixer Input Resistance RI (MIXER) − − 3.3 − kΩ Mixer Input Capacitance CI (MIXER) − − 2.2 − pF 3 S1T3361D CHARACTERISTIC GRAPH 4 LOW VOLTAGE/POWER NARROW BAND FM IF LOW VOLTAGE/POWER NARROW BAND FM IF S1T3361D APPLICATION CIRCUIT Audio Mute Mixer input 10.7MHz Scan Control Audio Filter Filter Amp out Amp in output Squelch SW input 10kΩ 51Ω 1.0uF 510kΩ 1.0uF 10nF 10nF 8.2kΩ 470kΩ 16 15 14 13 12 11 10 9 MIXIN GND MUTE SCAN SQ FOUT FIN AUDIO S1T3361D OSC 1 OSC MIXOUT VCC 2 68pF 10.24MHz 3 4 LIMIN DECOLP LING 5 6 7 455MHz Filter 20kΩ 220pF 0.1uF Vcc QUAD 8 0.1uF Quad coil 0.1uF In the above application circuit, the audio signal is recovered using a conventional quadrature FM detector. The absence of an input signal is indicated by the presence of noise above the desired audio frequencies. This “noise band” is monitored by an active filter and a detector. A squelch trigger circuit indicates the presence of noise (or a tone) by an output which can be used to control scanning. At the same time, an internal switch is operated which can be used to mute the audio. 5 S1T3361D LOW VOLTAGE/POWER NARROW BAND FM IF NOTES 6