BH7871FV video ics 1/5 stereo microphone amplifier for camcorder BH7871FV BH7871FV is a stereo microphone amplifier for camcorder. matrix circuit to emphasize stereo sound, microphone element power regulator, and filter to eliminate the wind noise all are incorporated in this ic. low operating voltage of 2.7v and small ssop-b20 package are other merits of this product. ! applications camcorder ! features 1) low power consumption 2) low input noise 3) microphone element power regulator and filter circuit for eliminating wind noise are incorporated into a single chip. 4) built in matrix circuit to enhance the stereo sound. ! absolute maximum ratings parameter symbol limits unit ? derating : ? 6.4mw / c for operation above ta=25 c. applied voltage power dissipation operating temperature storage temperature v cc max. pd topr tstg 4.0 640 ? 10 ~ + 70 ? 55 ~ + 125 v mw c c ! recommended operating conditions parameter symbol limits unit ? not designed for rediation resistance. ? please make sure that electrostatic destruction can be ocurred to use fine process. supply voltage v cc 2.7 3.3 v
BH7871FV video ics 2/5 ! block diagram gnd 12345678910 11 20 19 18 17 16 15 14 13 12 +13db +6db +0db reg 2.5v hpf on hpf off v cc pre + ? out +13db +6db +6db +6db +0db hpf on hpf off v cc pre + ? out hpf ctrl bias bias 2 v cc ripl intinl hpfctrl invoutr preoutl mtxinl mtxoutl hpfinl outl vcclch gnd intinr reg invoutl preoutr mixinr mtxoutr hpfinr outr vccrch
BH7871FV video ics 3/5 ! pin descriptions pin name functions pin voltage (v) pin form pin no. 1 4 2 5 6 7 gnd intinr reg preoutr hpfinr outr mtxinr invoutl mtxoutr vccrch invoutr hpfctrl intinl ripl ? i/o circuit ef:emitter follower, p-p:push pull, b:base, and c:collector. all numerical values are standardized values. vcclch hpfinl mtxoutl mtxinl preoutl outl gnd vcc lch matrix amp output internal mic input internal mic input ripple filter c terminal for bias vcc rch hpf input regurator output matrix amp input preamp output signal output invertor output preamp output matrix amp input matrix amp output invertor output hpf control input hpf input signal output 3 8 11 9 12 14 13 10 15 16 17 18 19 20 gnd 1.5 1.5 1.5 1.5 1.5 2.5 1.5 3.0 1.5 1.5 1.5 1.5 3.0 1.5 1.5 1.5 ? 1.5 1.5 ? ef (p-p) 75k ? ef (p-p) b ef (p-p) c 33k ? c (p-p) c (p-p) ef (p-p) 33k ? b ef (p-p) ef (p-p) 10k ? 75k 50k ? ! electrical characteristics (unless specified otherwise ta=25 c, v cc =3.0v, 20pin=h or open, input signal level ? 38.5dbv, observation terminal 9, 12pin) parameter symbol min. typ. max. unit conditions no input no input vin= ? 38.5dbv, f=1khz vin= ? 38.5dbv, f=1khz thd=1%, f=1khz rg = 1k ? vin= ? 38.5dbv, f=1khz (4 ? 17) pin3 output voltage for 30k ? load . hpf off, 18pin dc hpf on, 18pin dc consumption current (st) consumption current (mono) voltage gain distortion maximum output level i st i mono gv thd v om v on gv invlr v reg v thhpfh v thhpfl ? ? 16.0 ? ?9.2 ? ?1 2.3 2.2 0 2.6 2.0 19.0 0.05 ?6.2 ?98 0 2.5 ? ? hpf, ctl holding voltage output noise voltage inverter out l/r gain difference internal mic power supply output voltage 3.9 3.0 22.0 0.5 ? ?90 1 2.75 v cc 0.5 ma ma db % dbv dbv db v v v ? 1 ? 2 ? 2 ? 1 jis-a filter used. ? 2 400 to 30khz filter used. ? 2 ? 2
BH7871FV video ics 4/5 ! measuring circuit fig.1 gnd rin invoutl invoutr lin hpf on / off preoutl 1k 30k 47k 47k 1k 0.1 0.1 0.1 0.1 10 0.22 0.22 0.1 0.1 0.1 100 100 h 1 1 10 10k 10k 10k 10k 12345678910 11 20 19 18 17 16 15 14 13 12 +13db +6db +0db reg 2.5v hpf on hpf off v cc pre + ? out +13db +6db +6db +6db +0db hpf on hpf off v cc pre + ? out hpf ctrl bias bias 2 v cc rout rch sleep (mono / st) 47k 1 lout 47k 1 preoutr 47k 47k 47k 1 mtxoutr mtxoutl 47k 1 0.1 100 100 h
BH7871FV video ics 5/5 ! application example fig.2 gnd rin lin hpf on / off 2.2k 0.1 0.33 0.022 1 0.1 100 100 h 0.022 0.1 10 0.022 0.022 0.068 0.015 0.33 1 10 5.6k 22k 12k 0.068 18k 33k 6.8k 4700p 0.015 0 33k 22k 12k 2.2k 5.6k 12345678910 11 20 19 18 17 16 15 14 13 12 +13db +6db +0db reg 2.5v hpf on hpf off v cc pre + ? out +13db +6db +6db +6db +0db hpf on hpf off v cc pre + ? out hpf ctrl bias bias 2 v cc 18k 6.8k 4700p 0 rout lout 0.1 100 100 h rch sleep (mono / st) ! operating notes (1) output pin load resistance must be used in 10k ? or more. (2) each common impedance of two power lines from pin10 and pin11 make as small as possible. (3) in st mode, supply voltage of pin10, and pin11 must be the same power supply. in different voltage, decline of output voltage and abnormal operation can be occurred. (4) in mono mode, connect pin10 with gnd. abnormal operation can be occurred if the pin10 is not be connected with gnd. ! external dimensions ssop-b20 11 10 20 1 0.1 6.4 0.3 4.4 0.2 6.5 0.2 0.15 0.1 0.22 0.1 0.65 1.15 0.1 0.3min. 0.1
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