TDA7361 low voltage nbfm if system june1993 pin connection dip16 ordering number : TDA7361 . operation from 1.8v to 9v . low drain current (4ma, v s = 4v) . high sensitivity (-3db input limiting at 3 m v) . 8 m v input for 20db s/n . low external fair count description the TDA7361 is a low-power narrow band fm if demodulation system operable to less than 2 v supply voltage. the device includes oscillator, mixer, limiting am- plifier, quadrature discriminator, op. amp. squelch, scan control and mute switch. the TDA7361 is designed for use in nbfm dual conversion communication equipments using a 455 khz ceramic filter like cordless telephones, walkie-talkies, scan receivers, etc. so16 ordering number : TDA7361d 1/8 .com .com .com .com 4 .com u datasheet
block diagram pin function no name function 1-2 xtal oscillator connections for the colpitts xtal oscillator. the xtal may be replaced by an inductor (see figure 5) if the application does not require high stability. 3 mixer out the mixer is double balanced to reduce spurious products. the output impedance is 1.8kw to match the input impedance of a 455khz ceramic filter. 4 supply voltage must be well decoupled with a 100nf ceramic capacitor. 5 if limiter input input pin of the six stages amplifier with about 50 m v limiting sensitivity and 1.8k w input impedance. the if output is connected to the external quadrature coil (pin 8) via an internal 10pf capacitor. 6-7 decoupling good quality 100nf ceramic capacitors and a suitable layou are important. 8 quadrature coil a quadrature detector is uded to demodulate the 455khz fm signal. the q of the quad coil has direct effect on output level and distorsion (see figure 6). for proper operation the voltage should be 100mv rms . 9 audio output signal the audio output signal is buffered by an internal emitter follower. 10 operational amplifier input because of the low dc bias, the swing on the operational amplifier output is limited to 500mv rms . 11 operational amplifier output this can be increased by adding a resistor from the operational amplifier input to ground. 12 squelch input the squelch trigger circuit with a low bias on the input (pin 12) will force pin 13 high ; and pin 14 low. 13 scan control pulling pin 12 above mute threshold (0.65v) will force pin 13 to an impedance of about 60k w to ground and pin 14 will be an open circuit. 14 mute an hysteresis of about 50mv at pin 12 will effectively prevent jitter. 15 gnd ground connection 16 10.7mhz mixer input input of the wide-band mixer. normally used as 10mhz/455khz converter, it can be also used with input frequencies up to 60mhz. TDA7361 2/8 .com .com .com .com .com 4 .com u datasheet
absolute maximum ratings symbol parameter value unit v s supply voltage 9 v v i rf input voltage (pin 16) 1 v rms v 8 detector input voltage 1 v pp v 14 mute function voltage - 0.5 to +5 v t oper operating ambient temperature 0 to 70 o c t stg storage temperature - 65, + 150 o c thermal data symbol parameter so16 dip16 unit r th j-amb junction-ambient thermal resistance max. 200 100 o c/w electrical characteristics t amb =25 o c, unless otherwise specified symbol parameter test conditions min. typ. max. unit v s supply voltage range 1.8 4 9 v i s supply current squelch off squelch on 3.8 4.7 ma ma v i input quieting voltage s/n = 20db 8 m v v i input limiting voltage - 3db limiting 3 m v v o recovered audio output v i = 10mv 150 mv rms v 9 detector output voltage 1.5 v dc r 9 detector output impedance 400 w dtectot center frequency slope 150 mv/khz g v operational amplifier gain f = 10khz, g v =v 11 /v 10 40 55 db v 11 operational amplifier output voltage 1.5 v dc i b operational amplifier input bias current pin 10 20 na v t trigger hysteresis 50 mv r m mute switching impedance low high 50 10 w m w v 13 scan voltage pin 12 high (2v) pin 12 low (0v) 3.0 0 3.4 0.5 v dc v dc g c mixer converter gain 30 db r i input resistance 3.3 k w c i input capacitance 2.2 pf TDA7361 3/8 .com .com .com .com .com 4 .com u datasheet
figure 2 : test circuit figure 3 : supply current versus supply voltage figure 4 : fm if characteristics TDA7361 4/8 .com .com .com .com .com 4 .com u datasheet
figure 6 : effect of quadrature coil oqo on audio level and distortion figure 5 : colpitts xtal oscillator figure 7 : application information (49mhz cordless receiver) TDA7361 5/8 .com .com .com .com .com 4 .com u datasheet
so16 package mechanical data dim. mm inch min. typ. max. min. typ. max. a 1.75 0.069 a1 0.1 0.25 0.004 0.009 a2 1.6 0.063 b 0.35 0.46 0.014 0.018 b1 0.19 0.25 0.007 0.010 c 0.5 0.020 c1 45 (typ.) d 9.8 10 0.386 0.394 e 5.8 6.2 0.228 0.244 e 1.27 0.050 e3 8.89 0.350 f 3.8 4.0 0.150 0.157 l 0.4 1.27 0.016 0.050 m 0.62 0.024 s 8 (max.) TDA7361 6/8 .com .com .com .com .com 4 .com u datasheet
dip16 package mechanical data dim. mm inch min. typ. max. min. typ. max. a1 0.51 0.020 b 0.77 1.65 0.030 0.065 b 0.5 0.020 b1 0.25 0.010 d 20 0.787 e 8.5 0.335 e 2.54 0.100 e3 17.78 0.700 f 7.1 0.280 i 5.1 0.201 l 3.3 0.130 z 1.27 0.050 TDA7361 7/8 .com .com .com .com .com 4 .com u datasheet
information furnished is believed to be accurate and reliable. however, sgs-thomson microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of sgs-thomson microelectronics. specifications mentioned in this publication are subject to change without notice. this publication supersedes and replaces all information previously supplied. sgs-thomson microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of sgs-thomson microelectronics. ? 1994 sgs-thomson microelectronics - all rights reserved sgs-thomson microelectronics group of companies australia - brazil - france - germany - hong kong - italy - japan - korea - malaysia - malta - morocco - the netherlands - singa- pore - spain - sweden - switzerland - taiwan - thaliand - united kingdom - u.s.a. TDA7361 8/8 .com .com .com .com 4 .com u datasheet
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