The TDA7375A is a versatile, high-performance Class AB audio power amplifier housed in a Multiwatt 15 package. Specifically engineered for car radio systems, it features a flexible output stage that can be configured for four independent channels, two bridged channels, or a 2.1 (two single-ended + one bridged) system. It is highly regarded for its minimal external component requirements and integrated diagnostic features.

Specifications

• Operating Voltage: 8V to 18V DC (14.4V typical)
• Output Power (at 14.4V, 4 Ohm):
  • Double Bridge (2-Ch): 2 x 37W (Max) / 2 x 25W$ (@ 10% THD)
  • Quad Mode (4-Ch): 4 x 7W
• High Output Current: Capable of driving low-impedance loads.
• Total Harmonic Distortion (THD): 0.03% (at 1W output)
• Standby Current: 100uA
• Package: Multiwatt 15 (Vertical or Horizontal)

Features

• Versatile Output Configuration: Unlike many fixed amplifiers, the TDA7375A allows the user to bridge channels for high power or keep them separate for multi-speaker setups.
• Internal Fixed Gain: The gain is fixed internally (20dB for single-ended, 26dB for bridged), which eliminates the need for external feedback resistors and reduces noise.
• Diagnostic Output (Pin 10): Features a built-in clipping detector and fault indicator, which can signal the microcontroller if the audio is distorting or if a short circuit occurs.
• Silent Switch-On/Off: Integrated circuitry minimizes "pop" and "click" noises during power transitions.
• Robust Protection Suite:
  • Load Dump voltage surge protection.
  • Short circuit protection (Rail-to-Rail and across the load).
  • Thermal overload shutdown.
  • Reversed battery protection.

Common Applications

• High-Power Car Stereos: Acting as the primary amplifier for door and shelf speakers.
• Active 2.1 Speaker Systems: Using two channels for stereo satellites and the remaining two bridged for a subwoofer.
• Industrial PA Systems: Providing reliable, clear amplification for announcement systems.
• DIY Portable Speakers: Building high-output "boomboxes" powered by 12V lead-acid or Li-ion batteries.

Usage Tips

• Heatsink Requirement: The "37W x 2" rating generates significant heat. A large aluminum heatsink and thermal grease are mandatory to prevent the thermal protection from engaging.
• Power Supply Filtering: Due to the high current draw, use a large electrolytic capacitor (at least 2200uF to 4700uF) across the VCC and GND pins to prevent voltage sag.
• Standby Logic: To activate the chip, Pin 7 must be pulled to a voltage above 3.5V. If left floating or grounded, the amplifier remains in a low-power mute state.
• Input Decoupling: Use 0.47uF input capacitors to block DC components from your audio source.

Datasheet