ROHM BA3121F Data Sheet
Summary
The BA3121F/BA3123F are specialized ground isolation amplifiers engineered for high-fidelity car audio systems. They function by eliminating electrical noise and interference caused by wiring resistance within vehicle electrical sources, ensuring a pure audio signal for powerful performance. These two-channel ICs feature a high Common-Mode Rejection Ratio (CMRR) and low noise levels, allowing designers to create compact and highly reliable power amplifier solutions. This summary details the operational features, electrical specifications, and integration guide necessary for professional automotive electronics customization.
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Audio Accessory IC Series
Ground Isolation Amplifier
No.09092EAT01
BA3121F, BA3123F
●Description The BA3121F/BA3123F are ground isolation amplifiers developed for use in car audio applications. This IC efficiently eliminate problems caused by wiring resistance, and remove noise generated by the electrical devices used in automobiles. The capacitance values of the external capacitors required for the ICs are small to allow compact and reliable set design.
●Features 1) Large capacitors not required 2) High common-mode rejection ratio (57d B typ. at f = 1k Hz). 3) Low noise (VNO = 3.5μVrms Typ.). 4) Low distortion (THD = 0.002% Typ.). 5) Two channels.
●Applications Car audio systems
●Line up matrix BA3121F BA3123F Operation temperature －30～＋85C －40～＋85C
●Absolute maximum ratings (Ta = 25C)
Parameter Symbol Limits Unit Power supply voltage Vcc 18 V Power dissipation Pd 450* m W Operation BA3121F －30～＋85 ℃
temperature BA3123F －40～＋85 ℃ Storage temperature Tstg －55～＋125 ℃ ＊Reduced by 4.5m W in Ta of 1C over 25C.
●Recommended operating conditions (Ta = 25C)
Parameter Symbol Min. Typ. Max. Unit Power supply voltage Vcc 4 12 18 V
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Page Summary Contents For ROHM BA3121F Data Sheet
Manual Details
| Brand | ROHM |
|---|---|
| Pages | 9 |
| File Size | 332.01 KB |
| Published | June 21, 2026 |
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Frequently Asked Questions
Why is ground isolation needed in car audio systems?
It eliminates electrical noise generated by car electrics that enters the power amplifier input via the chassis.
How effective are these amplifiers at rejecting noise?
The typical Common-Mode Rejection Ratio (CMRR) is 57dB at 1kHz.
Are large external capacitors required for installation?
No, the required capacitance values for the external capacitors are small, allowing for compact design.
What voltage range should I use for operation?
The recommended power supply voltage (Vcc) ranges from a minimum of 4 V to 18 V.