TDA7388 4x40W Audio Power OpAmp

TDA7388 is a class AB radio amplifier designed for car radio applications. It allows the rail to rail output swing for fully complementary PNP/NPN output configuration. And it does not require any bootstrap capacitors. Hence, it is an extremely reduced boundary component that makes a compact set.

TDA7388 belongs to package Flexiwatt25 and is a quad bridge amplifier. Therefore, it has four output channels where four speakers can be connected. It has a high output capability with low noise and is a 4-channel amplifier with 25 pins.

TDA7388 Pinout Configuration

Features & Specifications

• High output power (4×45 W / 4 Ω max and 4×26 W / 4 Ω @14.4 V, 1 kHz, 10%)
• Low output noise
• Standby function
• Mute function
• Low distortion
• Automate at minimum supply voltage detection
• Low external component count
• Operating supply voltage V_S: 18 V
• DC supply voltage V_S(DC): 28 V
• Peak supply voltage (t=50 ms) V_PK: 50 V
• Output peak current I_O:
  Repetitive (duty cycle 10% @ f=10 Hz): 4.5 A
  Non-repetitive (t=100 μs): 5.5 A
• Power dissipation P_d: 80 W
• Quiescent current I_Q: 190 mA (typ)
• Output power P_O: 26 W (typ) (V_S = 14.4 V THD = 10%)
• Maximum power output P_max:
  41 W (@ V_S = 14.4 V)
  45W (@ V_S = 15.2 V)
• THD: 0.04% (@P_O = 4 W)

Note: Complete technical details about this IC can be found in the TDA7388 datasheet given at the end of the page.

Standard Test and Application Circuit of TDA7388 Amplifier

The below figure shows how to use TDA7388. It is a four-channel amplifier. Hence, we can connect four speakers with this amplifier as shown in the figure below.

SVR capacitor is used for ripple rejection and governs turn ON/OFF sequence. To achieve this application, the minimum recommended value of an SVR capacitor is 10 μF. SVR capacitors are connected at pin 10. TDA7388 has two modes; Standby and mute. These modes can be directly used by straight connection to V_s. To drive Muting and Standby pin, conventional/low-power transistors can be employed in absence of true CMOS ports and microprocessors. To smooth down the transitions and prevent audio noise, RC cells are used in the circuit.

Pin 22 is for mute mode. In normal conditions, a 10 μA current will flow through this pin. Hence, we can connect a maximum of 70 kΩ muting-series resistance (R₂). This resistance is sufficiently high to permit a muting capacitor reasonably small about 1 μF. If this resistance is more than recommended value, the voltage across pin 22 is more than the 1.5 V threshold value that fails to turn OFF when the mute line is down.

In order to achieve the pop-free transition, the time constant is assigned to a stand-by pin that will be slower than 2.5 V/ms.

Applications 

• In-Car Radios
• Can be used for Portable Speakers, Portable DVD Players, Game Machines
• Any possible Quad Bridge amplifier-based project.