49W BTL 4 Channel Audio Power Amplifier

This is a 49W – 4 Channel audio amplifier project that is built using TB2941HQ power Integrated Circuit which has a built-in four-channel BTL amplifier developed for car audio applications. The maximum output power is 49W using a pure complementary P-Ch and N-Ch DMOS output stage. In addition, a standby switch, a mute function, and various protection features are included. The audio mute function is enabled when jumper J1 is connected to 5V DC. The power supply can be turned ON or OFF via pin 4 (Stby). The threshold voltage of pin 4 is 2.2V to VCC (5V). The amplifier is turned ON when standby pin is connected to 5V DC using Jumper CN10. Onboard 5V regulator provided for standby and Mute function. When the headroom voltage is suppressed by the low VCC, the TB2941HQ switches outputs voltage from VCC/2 to VCC/4 and reduces the audible pop noise and the sound cutting. The TB2941HQ can reduce the distortion which is generated by low VCC because this amplifier circuit keeps the voltage gain of BLT outputs. In other words, if one side output of BTL has the voltage margin, its output can make up for the clipped waveform of the other side output.

Features

• Operating Power Supply 7.5V to 15V DC (VCC 15V = 49W output, VCC 13.7V=40W) THD 10%
• 49W Output with 4 Ohms Speaker
• 4XScrew Terminal Connector for Speaker Connections
• Screw Terminal Connector for Power Supply Input
• Female RCA Connector for Audio Inputs
• Voltage Gain GV 26dB
• Power LED
• High output power, low distortion, and low noise property
• Jumper for Mute Function
• Jumper for Standby Function
• Thermal Shutdown (Built in IC)
• Built-in various protection circuits over-voltage, short to VCC, short to GND, and output to output short)
• PCB Dimensions 79.06 x 51.44 mm

TB2941HQ Features

Thermal Shut Down

• Thermal shut down operates when the junction temperature exceeds 150°C (typ.).

Auto Muting Functions

• The TB2941HQ has two automatic mute functions.
• Low VCC Mute
• Stand-by Off Mute

Low VCC Mute

• When the supply voltage became lower than 5.5V (Typ.), The TB2941HQ operates the mute circuit automatically. This function prevents the large audible transient noise which is generated by low VCC

Over-Voltage

• Over-voltage It operates when the voltage exceeding the operating range is supplied to VCC pin. If the voltage falls, it will return automatically. When it operates, all outputs bias and high-side switch are turned off and all outputs are intercepted. The threshold voltage is 23 V (Typ.)

Standby-Off Mute

• The TB2941HQ operates the mute circuit during the standby-off transition. When the ripple voltage reached VCC/5, the standby-off mute is terminated. The external mute has to be ON till the internal mute-OFF

Short to VCC

• Short to VCC, Short to GND, Output to output short It operates when each output pin is in irregular connection and the load line goes over the SOA of the power transistor (DMOS). When it operates, all outputs bias circuits are turned off and all outputs are intercepted. If the irregular connection is canceled, it will return automatically.

Schematic

Parts List

Connections

Gerber View

Photos

Video

TB2941HQ Datasheet

Please follow and like us: