ROHM BH3854AS, BH3854AFS Datasheet

Audio ICs

Serial sound control IC

BH3854AS / BH3854AFS

The BH3854AS and BH3854AFS are signal processing ICs designed for volume and tone control in CD radio cassettes
and other audio products. Their three-line serial control enables them to control volume and tone on the basis of signals
from a microcomputer, etc.

Applications
CD radio cassettes, mini component stereo systems, car
stereos

Features

1) They facilitate direct serial control from a microcom­puter of volume (main volume) and tone (bass,
treble). DC control is also possible.

2) Volume is produced by a low-distortion, low-noise
VCA. Designed to minimize step noise.

3) Input amp can be used for gain adjustment, and ma­trix surround yields powerful sound.

4) Stable standard voltage supply and built-in I / O buff­er mean that few attachments are needed. SSOP32
package designed to save space.

5) Open collector has four outputs, which makes logic
control possible.

6) Excellent for volume and tone control devices in CD
radio cassettes, micro components, car stereos,
televisions, etc.

7) Digital GND pin and analog GND pin are separated
with an impedence of more than 1MΩ.

Absolute maximum ratings (Ta = 25C)

Recommended operating conditions (Ta = 25C)

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Audio ICs BH3854AS / BH3854AFS

Block diagram

Pin descriptions

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Audio ICs BH3854AS / BH3854AFS

FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 8V, f = 1kHz, BW = 20  20kHz,

VOL = Max., TONE = ALL FLAT, Rg = 600Ω, R

L = 10kΩ, INPUT AMP GAIN = 0dB)

FTiming chart constants

Note: About the output pins...

SPins 1 through 4 (pins 12 through 15) are reset when the power is turned ON.
SAfter the pins are reset, until the Vcc voltage setting for this IC (BH3854) is reached and the next data

Sis input, the pins only operate while the CK, DATA, and LATCH lines are all maintained at LOW.

SBe sure that no more than 9V is applied to any of the output pins.

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Audio ICs BH3854AS / BH3854AFS

Measurement circuit

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Audio ICs BH3854AS / BH3854AFS

Operation of measuring circuit switches

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