Here’s the circuit diagram of a 70W stereo power amplifier which built using single power IC STA550. The circuit is simple and require little additional electronic components to support the work of IC STA550.
This power stereo amplifier works with dual polarity / symmetrical power supply. Since based to the datasheet, the negative supply range is only -22V max, then you may use +/- 20V up to +/-22V supply. Don’t forget to mount a heatsink on the power IC STA550 to prevent overheating. With the features of this IC is owned, produced the audio output will not disappoint.
The STA550 is a fully integrated power module designed to implement a BASH® amplifier when used in conjunction with STABP01 digital processor.
- Monochip bridge stereo amplifier for bash® architecture
- 55+55w output power @ rl = 4/8?, thd = 0.5%
- 70+70w output power @ rl = 4/8?, thd = 10%
- High dynamic preamplifier input stages
- External programmable feedback type compressors
- Ac coupled input to class ab bridge output amplifier
- Precision rectifiers to drive the digital converter
- On-off sequence/ timer with mute and standby
- Proportional over power output current to limit the digital converter
- Absolute power bridge output transistor power protection
- Absolute output current limit
- Integrated thermal protection
- Power supply over voltage protection
- Flexiwatt power package with 27 pin
Download STA550 Datasheet for 70W power stereo amplifier circuit reference.