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 number 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 amplifier; mixer and osc (in corporating afc variable capacitor); z if amplifier, z quadrature detection; z tuning led driver. am section z rf amplifier, mixer and osc (with rf agc); z if amplifier (with if agc) z detector z tuning led driver af section z electronic volume control z fm muting tiger electronic co.,ltd
CXA1691M block diagram af power amp af if det agc am fe fm discrinminator fm fe tuning meter fm if 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 mute fm discri nf vol am osc afc fm osc reg out fm rf am rf in nc fm rf in fe gnd fm/am fe out select band fm/am am if in if in fm nc meter gnd if agc afc agc afc out det in af gnd out af vcc ripple filter pin configurations voltage (v) vcc=3v vcc=6v pin symbol description fm am fm am equivalent circuit 1 mute 0 0 0 0 2 fm discri phase-shift circuit, connect ceramic discriminator 2.18 2.70 4.88 5.43 1.2k 1k 2 3 nf negative feedback pin 1.5 1.5 3.0 3.0 27 af out power amplifier output pin 1.5 1.5 3.0 3.0 27 3 vcc *100 *100 gnd
CXA1691M pin configurations voltage (v) vcc=3v vcc=6v pin symbol description fm am fm am equivalent circuit 4 vol cont connect variable resistor for electronic volume control 1.25 1.25 1.25 1.25 20k 80k 4 gnd 5 am osc am local oscillation circuit 1.25 1.25 1.25 1.25 3.6k 5 6 afc afc variable capacitor pin 1.25 * 1.25 * 8 reg out regulator pin 1.25v(typ.) 1.25 1.25 1.25 1.25 6 8 1.25v (reg) 7 fm osc fm local oscillation circuit 1.25 1.25 1.25 1.25 7 9 fm rf connect fm rf tuning coil 1.25 1.25 1.25 1.25 12 fm rf in fm rf input pin 0.3 0 0.3 0 8k 1k 3pf 9 12 10 am rf in am rf input 1.25 1.25 1.25 1.25 10 vcc 11 nc 0 0 0 0 13 gnd(fe gnd) 0 0 0 0 14 fm/am fe out if output pin of fm and am, connect if filter 0.36 0.2 0.36 0.2 220 14 am fm
CXA1691M pin configurations voltage (v) vcc=3v vcc=6v pin symbol description fm am fm am equivalent circuit 15 band select fm and am bands selection switch pin. during gnd it becomes am and during open it becomes fm 0.84 0 0.88 0 15 gnd vcc 16 am if in input pin of am if 0 0 0 0 2k 16 17 fm if in input pin of fm if 1.3 0 1.3 0 360 17 gnd 18 nc 0 0 0 0 19 meter meter drive circuit (for tuning indicator) 1.6 1.6 4.5 4.5 n 1.25v gnd *3 19 20 gnd 0 0 0 0 21 afc/agc a fc pin of w band. during am, it determines time constant of agc 1.25 1.49 1.25 1.49 22 afc/agc afc pin of j band. during am, it determines time constant of agc 1.25 1.25 1.25 1.25 23 det out detection output pin 1.25 1.0 1.25 1.0 33k 23 21 22 39k gnd
CXA1691M pin configurations voltage (v) vcc=3v vcc=6v pin symbol description fm am fm am equivalent circuit 24 af in power amplifier input pin 0 0 0 0 24 11k 75k *4 *4 82k gnd 25 ripple filter ripple filter 2.71 2.71 5.4 5.4 17k 73k 90k vcc 25 26 vcc power supply pin 3.0 3.0 6.0 6.0 28 gnd power gnd 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 vo ltage of pin21 during w band. absolute maximum ratings (ta=25 c) characteristic symbol value unit supply voltage vcc 14 v allowable power dissipation p d 700 mw operating temperature topr -10~60 c storage temperature tstg -50~125 c recommended operating conditions parameter symbol value unit supply voltage vcc 2~7.5 v
CXA1691M electrical characteristics (unless otherwise specified: ta=25 c, vcc=6v) characteristics test conditions symbol min typ max unit am circuit current no signal, am i q1 3.5 10 ma fm circuit current no signal, fm i q2 7.0 14 ma fm front end voltage gain vin1=40db v, 100mhz g v1 32 39 46 db fm detection output level vin3=90db v, 10.7mhz (1khz 22.5khz,dev) v d1 39 77.5 155 mvrms fm-if knee level vin3=90db v 10.7mhz (-3dbpoint) (1khz 22.5khz,dev) v d2 24 32 db v fm detection output distortion factor vin3=90db v, 10.7mhz (1khz 75khz,dev) thd 1 0.3 2.0 % fm meter current vin3=60db v, 10.7mhz i b1 1.8 3.5 7.0 ma a m front end voltage gain vin2=60db v, 1660khz g v2 15 22 29 db am detection output level vin3=85 db v 455khz (1khz mod=30%) v d3 39 77.5 155 mvrms am-if voltage gain vin3 when 455khz (1khz mod=30%) output is -34dbm g v3 14 20 27 db v am detection output distortion factor vin2=95db v,1660khz vcc=7.8v (1khz mod=30%) thd 2 0.6 2.0 % am meter current vin3=85db v 455khz (1khz mod=30%) i b2 1.3 3.0 7.0 ma audio voltage gain vin=60db v, 10.7mhz vin4=-30dbm 1khz g v4 27 31.5 36 db audio distortion factor vin4=-20dbm,1khz 10.7mhz po=50mw,vin3=60db v thd 0.3 2.5 % audio output power vcc=6v, thd=10%, r l =8 ? po 400 500 mw muting level po=50mw vin3=off vin4=-20dbm 1khz v d4 8 15 22 db
CXA1691M test circuit 1 2 3 4 5 6 7 8 9 10 11 12 13 14 + 1uf 0.1uf 150 50k 33k 33k 24k 24k cf3 a b s1 24pf osc 100k 1pf 30pf 30pf 43pf 10pf 150uh 2200pf 1000pf 150 + 10uf 28 27 26 25 24 23 22 21 20 19 18 17 16 15 0.01uf a b s5 a b s4 0.01uf 0.01uf + 1uf + 4.7uf + 1uf 0.012uf a b s6 5k + 1uf + 0.047uf 0.047uf + 470uf 8 im v in 4 vd vcc gnd ve 0.01uf 0.01uf 25 100 2k a b s2 0.01uf 24pf 330 a bs3 ift 30pf 2k v in 2 vb va v in 1 v in 3 reg afc CXA1691M 10pf application circuit 1 2 3 4 5 6 7 8 9 10 11 12 13 14 + 4.7uf 0.1uf 150 cf3 ant bpf 1pf 28 27 26 25 24 23 22 21 20 19 18 17 16 15 cf1 CXA1691M 10k rv1 50k 100k 6pf 22pf 18pf 2pf + 10uf 0.01uf t1 100pf 2.2k 330 cf2 s1 fm am 0.01uf + 10uf + 4.7uf + 10uf 0.022uf + 0.47uf + 10uf + 470uf 0.1uf 0.1uf + 220uf s2 epj batt 1k
CXA1691M coil data am osc core diameter 0.06mm 2uew number of widings(t) f (khz) l( h) 1 to 3 qo 1 to 3 1 to 3 4 to 6 796 270 125 107 796 equivalent to l-5k7-h5 r12-1684x. mitsumi electric co.,ltd. or 7trs-8441x toko co., ltd. am ift core diameter 0.07mm uew number 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. mitsumi electric co.,ltd. or 7mc-7789n toko co., ltd. fm rf fm osc am bar antenna f (khz) l( h) primary secondary 796 650 91t 20t bpf pfwe8 (88 to 108mhz) soshin electric co., ltd. cf1 sfu-455b murata mfg. co., ltd. or bfcfl-455 toko co., ltd. cf2 sfe10.7ma5 murata mfg. co., ltd. cf3 cda10.7mc1 murata mfg. co., ltd.
CXA1691M characteristics curves
CXA1691M outline drawing sop28:
|
