This document describes the features and characteristics of the TDA7381 4 x 25 W quad bridge car radio amplifier, including high output power capability, clipping detector, low distortion, low output noise, standby function, mute function, automute, and diagnostics facility.
The TDA7381 is a Class AB audio power amplifier in a Flexiwatt25 package specifically designed for car radio applications. It features high output power capability (up to 4x30W at 4Ω) and utilizes a fully complementary PNP/NPN output configuration that allows rail-to-rail voltage swing without the need for bootstrap capacitors.
The device includes several protection and diagnostic features, such as clipping detection, thermal shutdown, and diagnostics for faults like output shorts to ground or supply. It is designed to minimize external component count with an internally fixed gain of 26 dB.
| Output power (4Ω, 1kHz, 10% THD) | 4 x 30 W @ 18V; 4 x 25W @ 14.4V |
|---|---|
| Output power (4Ω, 1kHz, 10% THD) | 4 x 25 W @ 14.4 V |
| Output power (4Ω, 1kHz, 10% THD) | 4 x 18 W @ 14.4 V |
| Output power (4Ω, 1kHz, 10% THD) | 4 x 15 W @ 13.2 V |
| Voltage gain | 26 dB (typical) |
| Quiescent current | 180 mA (max) |
| Output offset voltage | 100 mV (max) |
| Total Harmonic Distortion (THD) | 16.5 W (typ) @ 10% THD |
| Operating supply voltage | 18 V (max) |
| Peak supply voltage | 50 V (t = 50 ms) |
The amplifier delivers up to 4x30W into a 4Ω load at 18V, or 4x25W at 14.4V.
No, it has an internally fixed gain of 26 dB and requires no external compensation.
It detects clipping, output to GND short, output to Vg short, and thermal shutdown.