BA5406 stereo amplifier schematic circuit diagram

The BA5406 stereo amplifier, a monolithic integrated device developed by ROHM Semiconductors, offers notable performance features. This amplifier is capable of delivering 5W per channel when connected to a 4-ohm loudspeaker, all while operating on a 9V supply. What distinguishes amplifiers based on the BA5406 is their ability to function without the need for an output coupling transformer, enabling operation from a single power supply. Its versatile operating voltage range spans from 5 to 15V DC, making it particularly well-suited for low-power car audio applications.

In addition to automotive audio, the BA5406 finds utility in various applications, including portable audio players, stereo component systems, and televisions, among others. This IC boasts exceptional channel separation, effective channel isolation, minimal pop-up noise, low noise levels, and low thermal resistance. It is conveniently packaged in a 12-pin SIP format.

Features of BA5406

  • Good low voltage characteristics (Operation from Vcc=5 V)
  • Ripple filter (6pin) also can be used as a muting pin (Make 6pin GND potential)
  • Small thermal resistance package and simple heatsink design


In the depicted circuit diagram, the BA5406 is configured to provide a total of 5 watts per channel, resulting in 5×2 watts of output power for 4-ohm loudspeakers when supplied with a 9-volt voltage source.

Capacitor C3 plays the crucial role of a power supply filter, ensuring stable power delivery. For the left and right channels, C11 and C12 respectively function as input DC decoupling capacitors.

To enhance stability and minimize oscillations, a Zobel network is established for both channels. Specifically, C3 and R2 constitute the Zobel network for the left output, while C6 and R3 form an identical network for the right channel.

The volume control for the left and right channels is managed by potentiometers R5 and R6. Capacitors C4 and C8 are responsible for coupling the amplifier’s outputs to the speakers.

Noise filtering is efficiently handled by C9 and C10. Lastly, bootstrap capacitors, namely C1 for the left channel and C5 for the right channel, are integrated into the circuit to fulfill their specific roles.

Circuit diagram

BA5406 stereo amplifier schematic circuit diagram


  • BA5406 requires a proper heat sink.
  • The supply voltage range is 5 to 15V DC.
  • I used 9V DC for powering the amplifier.
  • The power supply must be well-regulated and filtered.
A capacitor is a device that stores electrical energy in an electric field. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance.

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