ROHM BA3838F, BA3837F, BA3837 Datasheet

1

Multimedia ICs

Vocal fader IC

BA3837 / BA3837F / BA3838F

The BA3837, BA3837F and BA3838F are ICs with an internal secondary active LPF for vocal cancellation functions
and mixing amplifier functions with high degrees of vocal cancellation. Three control pins are used to switch between
modes: the key controller input mode, through mode, vocal fader mode, sound multiplexing mode and mute mode.
By offering these functions on a single chip, these ICs can significantly reduce the number of external components.

•

Applications

Karaoke functions on stereo systems, portable stereos and VCRs

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Features

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Absolute maximum ratings (Ta = 25°C)

1) Single-chip IC with vocal fader, to erase vocals from
commercially available recordings.

2) Internal secondary active LPF for high degrees of
vocal cancellation (high synchronization rejection).

3) Three control pins for switching between 4 modes:
through, vocal fader, sound multiplexing and mute.

4) Key controller input and internal switches.

5) Low noise and low distortion.

6) Internal microphone mixing amplifier.

7) Available in two packages: DIP 16-pin and SOP 16­pin (BA3838F is available in SOP 16-pin only).

Parameter Symbol Limits Unit

18 V

DIP16

Pd mV

SOP16

Topr °C
Tstg °C

V

CC

1000

∗

1

550

∗

2

– 40 ~ + 85
– 55 ~ + 125

Power supply voltage
Power

dissipation
Operating temperature

Storage temperature

∗

1 Reduced by 10 mW for each increase in Ta of 1°C over 25°C.

∗

2 Reduced by 5.5mW for each increase in Ta of 1°C over 25°C.

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Recommended operating conditions (Ta = 25°C)

Parameter Symbol Min. Typ. Max. Unit

V

CC 5.4 — 10 V

V

CC 5.4 — 13 V

V

CC 4.0 — 15 V Ta = 25

°C

Ta = – 40°C ~ + 85°C
Ta = – 40°C ~ + 60°C

Conditions

Power supply voltage

∗

1

Power supply voltage

∗

1

Power supply voltage

∗

2

∗

2 BA3838F

∗

1 BA3837 and BA3837F

2

Multimedia ICs BA3837 / BA3837F / BA3838F

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Block diagram

16 15 14 13 12 11 10 9

123456 78

LOGIC

SW2

SW1

R

L + R

L – R

L

+

+

–

–

+

–

+

+

–

–

+

–
+

–
+

V

CC MIC LOUT FK TK LIN BIAS GND

C B A ROUT LP LP LP RIN

3

Multimedia ICs BA3837 / BA3837F / BA3838F

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Pin descriptions

1V

CC

2 MIC IN

3LOUT

4FK

5TK

Pin No.

BA3837 / BA3837F

BA3838F

51k

20k

20k

51

k

400

5

5

4

3

2

V

CC

V

CC

V

CC

V

CC

V

CC

V

CC

V

CC

1
2

V

CC

1
2

V

CC

V

CC

Pin name Equivalent circuit Function

Mixing input pin for microphone sound

Lch output pin

Input pin for key controller signals

Output pin for key controller signals

4

Multimedia ICs BA3837 / BA3837F / BA3838F

LIN

8

9 RIN

10 LPF1

LPF2

6

7

11

BIAS

GND

Pin No.

6

7

9

10

11

10

11

51k

51k

51k

51k

10.4k

10.4k

10.4k

10.4k

V

CC

V

CC

V

CC

V

CC

V

CC

V

CC

1
2

V

CC

1
2

V

CC

Pin name Equivalent circuit

L signal input pin

Signal bias circuit pin

R signal input pin

Function

LPF time constant pin

LPF time constant pin