This document is about the product information of BA3121F and BA3123F ground isolation amplifiers. These two amplifiers are applied in automotive audio systems and can effectively eliminate problems caused by wiring resistance and remove noise generated by automotive electronic devices. At the same time, the capacitance values of external capacitors are small, which can achieve compact and reliable design.
The BA3121F/BA3123F are ground‑isolation amplifiers developed for car audio systems. They eliminate wiring‑resistance problems and suppress noise from vehicle electronics, allowing a compact and reliable circuit design.
Key specifications include a wide supply voltage range, low quiescent current, very low output noise, high common‑mode rejection, and low total harmonic distortion. Typical applications are tape decks, tuners, and power amplifiers in automotive audio.
| Power supply voltage (Vcc) | 4 V – 12 V – 18 V |
|---|---|
| Quiescent current | 5.6 mA – 9.0 mA – 14.0 mA |
| Output noise voltage | 3.5 µVrms – 8.0 µVrms |
| Voltage gain | -1.5 dB – 1.5 dB |
| Total harmonic distortion (THD) | 0.002 % typical |
| Common‑mode rejection ratio (CMRR) | 57 dB typical at 1 kHz |
| Operating temperature range | -30 °C to +85 °C (BA3121F), -40 °C to +85 °C (BA3123F) |
| Maximum power dissipation | 450 mW (reduced 4.5 mW/°C above 25 °C) |
The recommended supply voltage is 4 V to 18 V, with 12 V typical for normal operation.
Typical output noise voltage is 3.5 µVrms.
The devices provide a typical CMRR of 57 dB at 1 kHz.
BA3121F operates from –30 °C to +85 °C, while BA3123F operates from –40 °C to +85 °C.