The LM4756 is a stereo audio amplifier capable of delivering 7W/channel at 10% distortion into a 4Ω or 8Ω load.
The LM4756 from National Semiconductor is a stereo audio power amplifier capable of delivering 7 W per channel into 4 Ω or 8 Ω loads at 10 % THD. It features an internally set gain of 30 dB, a 5 V‑controlled volume block providing up to 80 dB attenuation, and mute/standby functions that each give over 75 dB of attenuation.
The datasheet includes electrical characteristics, absolute maximum ratings, typical performance graphs, application circuits, and mechanical dimensions for the 15‑lead TO‑220 package. It also describes recommended RC low‑pass filters for mute and standby pins and provides a recommended power‑up/down sequence to minimize turn‑on/off pops.
| Maximum Operating Voltage | 28 V (max) |
|---|---|
| Standby‑mode Supply Current | < 10 mA (quiescent) |
| Mute Attenuation | over 75 dB |
| Signal‑to‑Noise Ratio | > 70 dB |
| Channel Separation | > 50 dB |
The mute function provides over 75 dB of attenuation from input to output.
In standby mode the device draws less than 10 mA of quiescent supply current.
The datasheet lists a typical supply voltage range of 15 V to 28 V.