The LM4906 is a 1W audio power amplifier designed for mobile phones and other portable communication devices. It can deliver 1W of continuous average power to an 8Ω BTL load with less than 1% distortion from a +5V power supply. The LM4906 is the first National Semiconductor Boomer Power Amplifier that does not require an external PSRR bypass capacitor. It also has an internal selectable gain of either 6dB or 12dB. In addition, no output coupling capacitors or bootstrap capacitors are required, making it ideal for low voltage portable applications. The LM4906 features advanced pop and click circuitry to eliminate noise during turn-on and turn-off transitions. It has a low-power consumption shutdown mode and internal thermal shutdown protection mechanism.
The LM4906 audio power amplifier is designed for portable communication devices such as mobile phones. It delivers up to 1 W continuous average power into an 8 Ω BTL load from a 5 V supply while keeping distortion below 1 % THD+N. The device operates from 2.6 V to 5.5 V and includes internal pop‑and‑click suppression, a shutdown mode, and thermal protection.
Key features include selectable gain (6 dB or 12 dB), no external output or PSRR bypass capacitors, ultra‑low shutdown current, and fast turn‑on time. The datasheet provides detailed electrical characteristics, absolute maximum ratings, typical performance curves, and package dimensions for both MSOP and LLP versions.
| Shutdown Current | 0.1 µA (typ) |
|---|---|
| Selectable Gain | 6 dB (2 V/V) or 12 dB (4 V/V) |
| Operating Voltage Range | 2.6 V – 5.5 V |
| Wake‑up Time | 5 ms |
| Supply Voltage (absolute max) | 6.0 V |
No, the LM4906 does not require external output or PSRR bypass capacitors.
Gain is selectable via a pin that provides either 6 dB (2 V/V) or 12 dB (4 V/V) gain.
The typical shutdown current is 0.1 µA.