25W Class A Power Audio Amplifier Wiring diagram Schematic

This is the 25W Class-A power audio amplifier schema. The output devices are MJL4281A (NPN) and MJL4302A (PNP), and have high bandwidth, fantastic SOA (safe operating area), high linearity and high gain. Driver transistors are MJE15034 (NPN) and MJE15035 (PNP). All devices are rated at 350V, using the power transistors having a 230W dissipation and the drivers are 50W.

25W Class-A Power Audio Amplifier Circuit Diagram

•  The supply voltage must be a maximum of ±25V. This supply is simply obtained from a 20-0-20V transformer, recommended current is 1A.
•  All resistors ought to be 1/4W or 1/2W 1% metal film for lowest noise, with the exception of R9, R10 and R15 which ought to be 1/2W varieties, and R13, R14 have to be 5W wirewound.
•  Using the suggested and advised 25V supplies, Q4 will typically not need a heatsink. The output drivers (Q5 and Q6) recommended to use a heatsink, even though it doesn’t have to be big.

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Hi Fi 25W Power Amplifier Class A

Hi-Fi 25W Power Amplifier (Class-A) Schematics Circuit

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TDA8922 Audio Amplifier 2 x 25W

TDA8922general description:

The TDA8922 is a high efficiency class-D audio power amplifier with very low dissipation. The typical output power is 2 × 25 W. The device is available in the HSOP24 power package with a small internal heatsink and in the DBS23P through-hole power package. Depending on the supply voltage and load conditions, a very small or even no external heatsink is required. The amplifier operates over a wide supply voltage range from ±12.5 to ±30 V and

consumes a very low quiescent current. TDA8922 Audio Amplifier 2 x 25W

TDA8922 features:

• High efficiency (∼90%)
• Operating supply voltage from ±12.5 to ±30 V
• Very low quiescent current
• Low distortion
• Usable as a stereo Single-Ended (SE) amplifier or as a mono amplifier in Bridge-Tied Load (BTL)
•  Fixed gain of 30 dB in Single-Ended (SE) and 36 dB in Bridge-Tied Load (BTL)
• High output power
• Good ripple rejection
• Internal switching frequency can be overruled by an external clock
• No switch-on or switch-off plop noise
• Short-circuit proof across load and to supply lines
• Electrostatic discharge protection
• Thermally protected.

TDA8922 aplications:

• Television sets
• Home-sound sets
• Multimedia systems
• All mains fed audio systems
• Car audio (boosters).

TDA8922 circuit:

TDA8922 layout and pcb:

TDA8922 datasheet:

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