The TB2903HQ is 4-ch BTL audio amplifier for car audio applications.
This IC can generate higher power: POUTMAX = 47 W as it includes the pure complementary P-ch and N-ch DMOS output stage.
It is designed to yield low distortion ratio for 4-ch BTL audio power amplifier, built-in standby function, muting function, and various kinds of protectors.
Additionally, Off-set detector is built in.

FEATUREs
•  High power output
: POUTMAX (1) = 47 W (typ.)
(VCC= 14.4 V, f = 1 kHz, JEITA max, RL= 4 Ω)
: POUTMAX (2) = 43 W (typ.)
(VCC= 13.7 V, f = 1 kHz, JEITA max, RL= 4 Ω)
: POUT(1) = 29 W (typ.)
(VCC= 14.4 V, f = 1 kHz, THD = 10%, RL= 4 Ω)
: POUT(2) = 25 W (typ.)
(VCC= 13.2 V, f = 1 kHz, THD = 10%, RL= 4 Ω)
•  Low distortion ratio: THD = 0.015% (typ.)
(VCC= 13.2 V, f = 1 kHz, POUT= 5 W, RL= 4 Ω
•  Low noise:  VNO= 90 µVrms (typ.)
(VCC= 13.2 V, Rg= 0 Ω, BW = 20 Hz~20 kHz, RL= 4 Ω)
•  Built-in standby switch function (pin 4)
•  Built-in muting function (pin 22)
•  Built-in Off-set detection function (pin 25)
•  Built-in various protection circuits:
 Thermal shut down, overvoltage, out to GND, out to VCC, out to out short
•  Operating supply voltage: VCC (opr)= 9~18 V (RL= 4 Ω)