TIGER ELECTRONIC CO.,LTD FM/AM RADIO CIRCUIT CXA1691M DESCRIPTION The CXA1691M is a one-chip FM/AM radio IC designed for radio-cassette tape recorders and headphone tape recorders. FEATURE z Small nu mb er of peripheral components z Low current consumption (Vcc=3V) FM: I D =5.3mA (Typ.) AM: I D =3.4mA (Typ.) z Built-in FM/AM select switch z Large output of AF amplifier FUNCTIONS FM section z RF a mplifier; Mixer and OSC (in corporating AFC variable capacitor); z IF a mplifier, z Quadrature detection; z Tuning LED driver. AM section z RF a mplifier, Mixer and OSC (with RF AGC); z IF a mplifier (with IF AGC) z Detector z Tuning LED driver AF section z Electronic volu me control z FM mu ting 1/10 CXA1691M BLOCK DIAGRAM Ripple AF AF GND OUT Vcc Filter IN 28 27 26 25 24 DET OUT AFC AGC 23 22 AFC IF AGC GND 21 20 FM/AM FM AM Band Meter NC IF IN IF IN Select 19 18 17 16 15 AF IF DET AGC Tuning Meter AF POWER AMP AM FE FM Discrinminator FM IF FM FE 1 2 3 Mute FM NF Discri 4 5 VOL 6 7 8 9 10 11 12 13 AM AFC FM Reg FM AM NC FM FE OSC OSC OUT RF RF IN RF IN GND 14 FM/AM FE OUT PIN CONFIGURATIONS Pin Symbol 1 MUTE 2 FM DISCR I Description Voltage (V) Vcc=3V Vcc=6V FM AM FM AM 0 Phase-Shift circuit, Connect cera mic discriminator 0 0 Equivalent circuit 0 2 1K 2.18 2.70 4.88 5.43 1.2K Vcc 3 NF Negative feedback pin 1.5 1.5 3.0 *100 3.0 27 *100 27 AF OUT Power a mpl ifier output pin 1.5 1.5 3.0 3.0 GND 3 2/10 CXA1691M PIN CONFIGURATIONS Pin Symbol Description Voltage (V) Vcc=3V Vcc=6V FM AM FM AM Equivalent circuit 4 4 VOL CONT 20K Connect variable resistor for electronic 1.25 1.25 1.25 1.25 volu me control 80K GND 5 5 AM OSC 6 AFC 8 REG OUT AM local oscillation circuit AFC variable capacitor pin Regulator pin 1.25V(Typ.) 3.6K 1.25 1.25 1.25 1.25 1.25 * 1.25 * 1.25 1.25 1.25 1.25 8 6 1.25V (REG) 7 7 FM OSC FM local oscillation circuit 1.25 1.25 1.25 1.25 9 FM RF Connect FM RF tuning coil 1.25 1.25 1.25 1.25 9 3pF 8K 12 12 FM RF IN FM RF input pin 0.3 0 0.3 1K 0 10 10 AM RF IN 11 NC AM RF input 13 GND(FE GND) 14 FM/AM FE OUT IF output pin of FM and AM, Connect IF filter 1.25 1.25 1.25 1.25 0 0 0 0 0 0 0 0 Vcc FM AM 0.36 0.2 0 .36 0 .2 220 14 3/10 CXA1691M PIN CONFIGURATIONS Pin Symbol Description Voltage (V) Vcc=3V Vcc=6V FM AM FM AM Equivalent circuit Vcc 15 BAND SELECT FM and AM band s selection switch pin. During GND 0.84 it becomes AM and during open it becomes FM 0 0.88 0 15 GND 16 16 AM IF IN Input pin of AM IF 0 0 0 0 17 FM IF IN Input pin of FM IF 1.3 0 1.3 0 2K 17 360 GND 18 NC 0 0 0 0 1.25V 19 METER Meter drive circuit (For tuning indicator) 1.6 1.6 4.5 19 *3 4.5 N 20 0 0 0 0 AFC pin of W band . During AM, it 21 AFC/AGC 1.25 1.49 1.25 1.49 determines ti me constant of AGC AFC pin of J band. During AM, 22 AFC/AGC 1.25 1.25 1.25 1.25 it determines time constant of AGC GND GND 23 DET OUT Detection output pin 22 33K 39K 21 23 1.25 1.0 1 .25 1 .0 GND 4/10 CXA1691M PIN CONFIGURATIONS Pin Symbol Voltage (V) Vcc=3V Vcc=6V FM AM FM AM Description Equivalent circuit 24 24 AF IN 11K *4 Power a mpl ifier input pin 0 0 0 0 *4 75K 82K GND Vcc 17K 25 25 RIPPLE FILTER Ripple filter 2.71 2.71 5.4 5 .4 73K 90K 26 Vcc 28 GND Power supply pin 3.0 Power GN D 0 3.0 6.0 6.0 0 0 0 * Note: The pin voltage of pin 6 during AM, it is the same pin voltage of pin22 during J BAND and is the same pin voltage of pin21 during W BAND. ABSOLUTE MAXIMUM RATINGS (Ta=25 °C) Characteristic Symbol Value Unit Vcc 14 V PD 700 mW Operating te mperature Topr -10~60 °C Storage Temperature Tstg -50~125 °C Supply Voltage Allowable power dissipation RECOMMENDED OPERATING CONDITIONS Para meter Symbol Value Unit Supply voltage Vcc 2~7.5 V 5/10 CXA1691M ELECTRICAL CHARACTERISTICS (Unless otherwise specified: Ta=2 5°C, Vcc=6V) Characteristics Test conditions Symbol Min Typ Max Unit AM circuit current No signal, AM IQ1 3.5 10 mA FM circuit current No signal, FM IQ2 7.0 14 mA FM front end voltage gain Vin1=40dBµV, 100MHz FM detection output Vin3=90dBµV, 10.7MHz level (1kHz， 22.5kHz,DEV) Vin3=90dBµV 10.7MHz (-3dBpoint) FM-IF knee level (1kHz， 22.5kHz,DEV) FM detection output Vin3=90dBµV, 10.7MHz distortion factor (1kHz， 75kHz,DEV) FM meter current Vin3=60dBµV, 10.7MHz GV1 32 39 46 dB VD1 39 77.5 155 mVr ms VD2 24 32 d BµV THD 1 0.3 2.0 % 1.8 3.5 7.0 mA 15 22 29 dB 39 77.5 155 mVr ms 14 20 27 d BµV 0.6 2.0 % 1.3 3.0 7.0 mA 27 31.5 36 dB 0.3 2.5 % IB1 AM front end vo ltage gain Vin2=60dBµV, 1660kHz GV2 AM detection output Vin3=85 dB µV，4 5 5 kHz VD3 level (1kHz， MOD=30%) Vin3 when 455kHz GV3 AM-IF voltage gain (1kHz， MOD=30%) Output is -34dBm Vin2=95dBµV,1660kHz AM detection ou tput Vcc=7.8V THD 2 distortion factor (1kHz， MOD=30%) Vin3=85dBµV， 455kHz AM meter current IB2 (1kHz， MOD=30%) Vin=60dBµV, 10.7MHz Audio voltage gain GV4 Vin 4 = - 3 0 dB m， 1 k H z Vin4=-20dBm,1kHz 10.7MHz ， Audio distortion factor THD Po=50mW, Vin3=60dBµV Vcc=6V, THD=10%, Audio output power Po R L =8 Ω Po=50mW ， Vin3=OFF， Muting level VD4 Vin 4 = - 2 0 dB m， 1 k H z 400 500 8 15 mW 22 dB 6/10 CXA1691M TEST CIRCUIT A V IN 3 0.01uF 4.7uF 23 22 A S4 B B S3 S5 A B 1uF 0.01uF B 25 24 1uF 5K 0.012uF 1uF 0.047uF 0.047uF + + 27 26 28 S6 A + 470uF + 8 VE + GND + Vcc IM VD 0.01uF V IN 4 21 20 18 17 16 19 30pF 15 IFT VB CXA1691M 6 7 8 9 10 11 12 13 2K 14 B VA 0.01uF V IN 1 0.01uF 10pF 25 30pF 30pF 24pF 10pF 150uH 0.01uF V IN 2 100 10uF 150 43pF OSC 50K 100K CF3 1uF 2200pF S1 A B A S2 1000pF 1pF 330 5 + 24K 24K 4 3 150 0.1uF 33K 2 + 1 24pF 33K 2K REG AFC CF2 10uF 0.01uF 330 T1 2.2K 4.7uF 10uF 0.022uF + 470uF + + + BATT 10uF + 220uF + 0.1uF APPLICATION CIRCUIT 1K S1 FM 0.47uF 28 CF1 + EPJ 0.1uF 27 26 23 22 21 25 24 AM 18 17 16 20 19 100pF 15 S2 CXA1691M 150 3 + 4.7uF CF3 0.1uF 2 4 5 6 7 8 9 10 11 12 13 14 10uF 100K 1pF 0.01uF + 1 BPF 10K 2pF 18pF ANT 6pF 22pF RV1 50K 7/10 CXA1691M Coil Data Co re dia meter φ0.06 mm 2UEW AM OSC f (kHz) L( µH) 1 to 3 Qo 1 to 3 796 270 125 Equivalent to L-5K7-H5 Nu mb er of widings(t) 1 to 3 4 to 6 107 796 R12-1684X. Mitsumi Electric Co.,Ltd. or 7TRS-8441X TOKO C o ., Ltd. Co re d ia meter φ0.07 mm UEW AM IFT Nu mb er of widings (t) Co(pF) 1 to 3 Qo 1 to 3 1 to2 2 to 3 4 to 6 180 90 111 35 7 Equivalent to 21K7-H5 R12-8558A. Mitsu mi Electric Co.,Ltd. or 7MC-7789N TOKO C o ., Ltd. FM RF FM OSC AM bar antenna BPF f (kHz) L( µH) Pri ma ry Secondary 796 650 91t 20t PFWE8 (8 8 to 10 8MHz) Soshin Electric Co ., Ltd . CF1 SFU-455B Murata Mfg. Co., Ltd. Or BFCFL-455 TOKO Co., Ltd. CF2 SFE10.7MA5 Mu rata Mfg. Co., Ltd. CF3 CDA10.7MC1 Murata Mfg. Co., Ltd. 8/10 CXA1691M CHARACTERISTICS CURVES 9/10 CXA1691M OUTLINE DRAWING SOP28: CXA1691M 10/10