features ? incorporates gr504, 3 stage amplifer chip ? designed to drive class d integrated receivers ? adjustable symmetrical peak clipper for mpo control ? two low noise inverting preamplifiers ? mid-supply referenced output stage ? anti-aliasing filter network standard packaging ? hybrid typical dimensions: 0.244 in x 0.102 in x 0.115 in (6.20 mm x 2.59 mm x 2.92 mm) description the GS3018 contains gennum's gr504 class d preamplifier chip, six capacitors and one resistor. capacitor c1 on the hybrid, in conjunction with r mic on the gr504 chip, form a high pass filter which provides a very well regulated supply voltage for the microphone. resistor r1, capacitor c2 and the output impedance of the microphone ( ? 4 k w ) also form a high pass filter with a corner frequency of approximately 240 hz. GS3018 - hyb data sheet provisions have been made on the hybrid to allow the manufacturer to increase or decrease this corner frequency with the addition of a capacitor. as the class d receiver utilizes a 100 khz clock, lower harmonics of the frequency may feed back into the system and interact with the incoming signal from the microphone. capacitors c5 and c6 have been added to the hybrid to minimize this effect, known as "aliasing". blocks a and b on the gr504 are low noise inverting preamplifiers with an open loop voltage gain of typically 50 db. typically, the volume control potentiometer would be placed around block a, and block b used either as a gain trim stage or as a telecoil amplifier. the voltage gain of these two blocks is determined by the ratio of the input resistance to the value of the feedback resistor. with 100 k w potentiometer used as a feedback resistor for both stages, block a would have a maximum gain of 20 db, and block b a gain of 26 db. block c is a mid-supply referenced output stage designed to drive class d receivers. it is typically capable of 670 mv peak to peak output voltage swing and 14 db of mpo (maximum power output) control with a 10 k w mpo potentiometer. the gain of the output stage is fixed at typically 16 db. functional block diagram gr504 GS3018 vc1 vc2 b out1 b out2 v mic r mic gnd out - mgnd 5k b a c2 47n c1 4? r1 10k v b mpo c in c5 1n8 c6 1n8 c3 68n c4 68n r p1 r p2 c3 b rin b in in c2 4 2 3 1 13 7 7 5 5 6 6 - c 10 9 9 8 8 16 11 12 14 15 4 2 3 2a 110 - all resistors in ohms, all capacitors in farads unless otherwise stated. class d preamp with anti-aliasing network revision date: may 1998 document no. 521 - 09 - 03 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
521 - 09 - 03 2 parameter symbol conditions min typ max units supply current i amp 165 240 315 m a stage a and b input bias voltage v bias 500 580 650 mv gain (pin 2 to pin 8) gain ab v in = -60dbv 40 44 48 db output stage input bias voltage v cin 550 612 670 mv voltage gain (pin 15 to pin 10) gain c v in = -50dbv, r mpo = 0 14 16 18 db maximum output level mpo v in = -22dbv, r mpo = 0 -14.5 -12.5 -10.5 dbv mpo range d mpo v in = -22dbv, r mpo = 10k 12 14 16 db gain at 10 khz gain 10khz v in = -55dbv, r mpo = 0 0 4.5 9.0 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). pad connection caution class 1 esd sensitivity absolute maximum ratings parameter value / units supply voltage 3 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 9 3 2 1 14 11 4 5 6 7 8 9 10 in mgnd c2 br in vc1 vc2 b out2 v b out c in c3 gnd mpo b in b out1 v mic 16 15 12 13
521 - 09 - 03 3 100k 100k 1khz 0? 50k 1.3vdc v in v in gr504 GS3018 r mic - 5k b a c1 4? r mpo c5 1n8 c6 1n8 c3 68n c4 68n r p1 r p2 3khz 4 2 1 13 7 7 5 5 6 6 - c 9 9 8 8 16 11 12 14 15 4 2 3 110 2a - 3 10 c2 47n r1 10k all resistors in ohms, all capacitors in farads unless otherwise stated. fig. 2 typical hearing instrument application 1 gr504 GS3018 mic r mic - 5k b a c1 4? c5 1n8 c6 1n8 c3 68n c4 68n r p1 r p2 4 2 3 1 13 7 7 5 5 6 6 - c 10 9 9 8 8 16 11 12 14 15 4 2 3 1 2a 10 - r vc 100k r gt 100k 1.3vdc r mpo 10k class d integrated receiver c2 47n r1 10k all resistors in ohms, all capacitors in farads unless otherwise stated. fig. 1 production test circuit
521 - 09 - 03 4 gr504 GS3018 mic r mic - 5k b a c1 4? c5 1n8 1 c6 1n8 c3 68n c4 68n r p1 r p2 4 2 3 1 13 7 7 5 5 6 6 - c 10 9 9 8 8 16 11 12 14 15 4 2 3 1 2a 10 - r vc 100k telecoil 1.3vdc r mpo 10k rcvr c2 47n r1 10k all resistors in ohms, all capacitors in farads unless otherwise stated. fig. 3 typical application circuit mic + volume control rmpo r gt battery 1 3 2 1 15 16 11 4 5 6 7 8 9 10 14 13 + - 12 rec + fig. 4 typical assembly diagram
521 - 09 - 03 5 fig. 8 frequency response vs c in fig. 9 thd vs input (r fa =100k, r mpo =0) 50k gr504 GS3018 r mic - 5k b a c1 4? c5 1n8 c6 1n8 c3 68n c4 68n r p1 v out r p2 4 2 3 v in 1khz c ext 3k9 a b 1 13 7 7 5 5 6 6 - c 10 9 9 8 8 16 11 12 14 15 4 2 3 1 2a 10 - r fa 100k r fb 100k 1.3vdc r mpo c2 47n r1 10k s1 fig. 5 characterization circuit (used to generate typical curves) all resistors in ohms, all capacitors in farads unless otherwise stated. c ext =22nf(s1=b) c ext =10nf(s1=b) 20 100 1k 10k 20k frequency (hz) -100 -96 -92 -88 -84 -80 -76 -72 -68 input (dbv) output (dbv) -140 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 input (dbv) r fa =100k r fa =47k r fa =22k r fa =10k fig. 6 input vs output (r mpo = 0) -100 -90 -80 -70 -60 -50 -40 input (dbv) fig. 7 maximum power output vs r mpo r mpo =0 r mpo =3k3 output (dbv) -10 -15 -20 -25 -30 -35 -40 -45 -50 -10 -20 -30 -40 -50 -60 -70 -80 2 -2 -6 -10 -14 -18 -22 -26 -30 relative output (db) 10 9 8 7 6 5 4 3 2 1 0 thd (%) 47nf(s1=a) r mpo =10k
521 - 09 - 03 6 9 3 2 1 14 11 4 5 6 7 8 9 10 16 15 12 13 0.244 (6.20) 0.102 (2.59) c1 0.125 (3.18) max GS3018 xxxxxx dimension units are in inches. dimensions in parenthesis are in millimetres converted from inches and include minor round-off errors. 1.0000 inches = 25.400 mm. smallest pad 0.020 x 0.020 (0.51 x 0.51). largest pad 0.034 x 0.020 (0.86 x 0.51). dimension tolerances 0.003" ( 0.08) unless otherwise specified. pad numbers and capacitor numbers for illustration only. xxxxxx - work order number. this hybrid is designed for point to point manual soldering. fig. 9 hybrid layout and dimensions 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 march 1994 gennum corporation. all rights reserved. printed in canada. revision notes: updated to data sheet
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