features ? handles high input levels cleanly (up to 100 mvrms) ? low thd and imd distortion ? unique twin average detectors ? dual channel signal processing ? adjustable agc threshold levels ? highpass filter with adjustable corner frequency ? 2:1 compression of high frequencies standard packaging ? chip (84 x 112 mils) au bump GC514 - data sheet document no. 520 - 96 - 03 description the GC514 integrated circuit is a dynamically adaptive loudness growth equalizer. its gain and frequency response are dependent on the user's environment and provide treble increase at low levels (till). the unique twin average detector circuit dramatically reduces pumping effects and is optimized for mild-to-moderate hearing loss. GC514 has two signal paths for dual channel processing incorporating four amplifying stages ( a, b, c, d ) and an agc processing circuit. stage a is a highpass channel with 2:1 compression. stage b is a wideband buffer. the sum of the two paths gives a high frequency boost to low level signals which gradually compresses to a flat response at high input levels. stage c is used for volume control adjustment, while stage d is a class a power amplifier with receiver bias current adjustment. dynamic equalizer chip 4 5 c d + - + - 24k 0.92v 8 gnd v b v reg 7 15 1 14 16 2 regulator slow average detector fast average detector 17 r th current reference 2:1 compression control 12 r e 340 c sad d out 11 3 9 rec 10 12k a b 13 6 rectifier v b GC514 b in r sad c fad r fad b out a out c out c in a in all resistors in ohms, all capacitors in farads unless otherwise stated. patent pending. functional block diagram revision date: may 1998 gennum corporation p.o. box 489, stn. a, burlington, ontario, canada l7r 3y3 tel. +1 (905) 632-2996 web site: www.gennum.com e-mail: hipinfo@gennum.com
2 520 - 96 - 03 parameter symbol conditions min typ max units amplifier current i amp v in = 0 v rms 120 230 330 m a minimum voltage v b 1.1 - - v stage a input impedance z in a -12 -k w maximum gain (no compression) a max a s3, s4 closed; v in = -80 dbv 24.5 26.5 30 db minimum gain a min a v in = -20 dbv - -11 - db gain in compression a comp a s3 closed; v in = -80 dbv 16.7 18.2 19.7 db high level distortion thd a v in = -20 dbv - 0.4 2.0 % compression ratio comp v in = -80 dbv and -60 dbv 1.74:1 1.95:1 2.11:1 ratio agc threshold v thr - -94 - dbv stage b input bias current i bias b 02555na output source capacity i source b v p12 = 0.4 v; v p13 = 0.5 v 15 30 - m a output voltage sink v sinklow b note 1 200 300 500 mv stage c input bias current i bias c -25 - 25 na output source capacity i source c v p9 = 0.4 v; v p10 = 0.5 v 15 30 - m a output voltage sink v sinklow c note 2 200 300 500 mv stage d minimum transducer current i trmin 130 160 190 m a maximum current sink i sink s1 closed 3 6 - ma output impedance z out 20 24 28 k w emitter bias voltage v re 48 52 56 mv regulator regulator voltage v reg 0.89 0.92 0.97 v supply rejection psrr - 57 - db all parameters and switches remain as shown in the test circuit unless otherwise stated in conditions column v qx quiescent (unbias) voltage measured on the pin, (nothing connected to the pin) v px actual voltage measured on the pin at given condition (x is pin number) caution class 1 esd sensitivity absolute maximum ratings parameter value / units supply voltage 5 vdc power dissipation 25 mw operating temperature range -10 c to 40 c storage temperature range -20 c to 70 c conditions: frequency = 1 khz, temperature = 25 c, supply voltage v b = 1.3 v electrical characteristics notes: 1. v sinklow b = v q13 - v p13 [ i p12 = 1 m a, i p13 = 15 m a ] 2. v sinklow c = v q10 - v p10 [ i p9 = 1 m a, i p10 = 15 m a ] chip pad connection c sad r fad r th c fad b out b in rec c out r sad gnd a in r e d out c in v reg v b 5 a out 6 4 3 2 7 8 9 10 11 1 12 13 14 17 16 15
3 520 - 96 - 03 all resistors in ohms, all capacitors in farads unless otherwise stated. all resistors in ohms, all capacitors in farads unless otherwise stated. 4 5 c d + - + - 24k 0.92v 8 7 15 1 14 16 2 regulator slow average detector fast average detector 17 current reference 2:1 compression control 12 340 11 3 9 10 12k a b 13 6 rectifier v b GC514 2? 3k9 1m 0 1 1m 1.3v 0?2 0?2 100k 100k s3 s4 1.3v s1 0? v in 68k 4 5 c d + - + - 24k 0.92v 8 GC514 7 c1 2 2 c7 2 2 c6 0 1 r7 100k r6 100k 15 1 14 16 2 regulator slow average detector fast average detector 17 r1 68k current reference 2:1 compression control 12 c4 0 1 340 11 3 9 10 c5 0 1 r4 50k r5 50k r3 50k 12k r2 50k c3 0 1 c2 3n9 a b 13 6 rectifier v b r e 100 100k r vc v b ek3024 ed1913 c rec 4n7 fig.1 test circuit fig. 2 typical hearing instrument application
4 520 - 96 - 03 17 16 c d + - + - 24k 0.92v 13 GC514 14 2? 2? 0? 100k 100k 7 3 8 2 regulator slow average detector fast average detector 5 r th1 current reference 2:1 compression control 12 340 11 1 9 10 0? 12k a b 6 rectifier v b v b 1.3v 4 r th2 v b 2.6v 15 0? all resistors in ohms, all capacitors in farads unless otherwise stated. fig. 3 characterization circuit (used to generate curves) 60 50 40 30 20 gain (db) -30 -40 -50 -60 -70 -80 output level (dbv) -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 input level (dbv) fig. 5 stage a transfer functions for different r th1 resistors output level (dbv) -30 -40 -50 -60 -70 -80 r th2 =22k w r th2 =10k w r th2 =5.1k w r th2 =0 w ?=2khz ?=2khz stage b stage c r th2 =0 10 100 1k 10k 100k frequency (hz) fig. 4 preamplifier open loop voltage gain r th1 =68k w 10 2k2 1m 10 1m r th1 =0 w r th1 =15k w r th1 =33k w r th1 =68k w -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 input level (dbv) fig. 6 stage a i/o transfer functions for different r th2 resistors
5 520 - 96 - 03 document identification: data sheet the product is in production. gennum reserves the right to make changes at any time to improve reliability, function or design, in order to provide the best product possible. gennum corporation assumes no responsibility for the use of any circuits described herein and makes no representations that the y are free from patent infringement. ? copyright april 1992 gennum corporation. all rights reserved. printed in canada. revision notes: updated to data sheet
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