2x5W AMP click

2x5W AMP click functions as an amplifier and features the TDA7491LP 2x5-watt dual BTL class-D audio amplifier. The click is designed to run on either 3.3V or 5V power supply. It communicates with the target MCU over the following pins on the mikroBUS™ line: AN, RST, CS, PWM, INT.

2x5W AMP click features a 3.5mm input jack and four output screw terminals for connecting passive speakers.

Note: In order to achieve full 2x5W output power, keep in mind that you need to supply enough current to the chip. 
This is achievable with the EXT PWR header, but you need to switch over the AMP VCC to the left position.

Note: a 3.5mm stereo cable and wired passive speakers are not included in the offer.

Class-D audio amplifier

Class-D audio amplifiers (switching amplifiers) are very energy efficient. They reduce power losses on the output device by operating as an electronic switch, rather than as linear gain devices, like in A or AB amplifiers.

These kinds of amplifiers are ideal for compact, high power applications.

TDA7491LP audio amplifier

The amplifier has three operating modes:

Standby mode: all circuits are turned off, very low current consumption. The amplifier uses a maximum of 10uA in standby mode.

Mute mode: inputs are connected to ground and the positive and negative PWM outputs are at 50% duty cycle.

Play mode: the amplifiers are active.

Simple control

The click does not use a standard serial communication, like I2C or SPI - it's controlled by a few pins on the mikroBUS™ line. The state of these pins can either be HIGH or LOW (mute, gain, enable). The operating modes and gain are set with input pins.

Specifications

Pinout diagram

This table shows how the pinout on 2x5W AMP click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Gain 0 pin	GN0	1	AN	PWM	16	MUTE	Mute control
Gain 1 pin	GN1	2	RST	INT	15	DIA	Diagnostic pin
Standby control	STB	3	CS	TX	14	NC
	NC	4	SCK	RX	13	NC
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
Power supply	+3.3V	7	3.3V	5V	10	+5V	Power supply
Ground	GND	8	GND	GND	9	GND	Ground

Jumpers and settings

LEDs, buttons, connectors and switches

Programming

The library has two helper functions for setting the gain and the mode via output pins.

Code snippet

The demo shows how to initialize, set the mode and the gain of the click.

01 void main()
02 {
03     system_init();
04
05     click_2x5W_gain(CLICK_2X5W_AMP_20_DB);
06     click_2x5W_mode(CLICK_2X5W_AMP_MODE_PLAY);
07
08     while( 1 )
09     {
10         if(Button(&GPIOE_IDR, 11, 100, 1))
11         {
12             click_2x5W_gain((click_2x5w_amp_gain_t)(++gain % 4));
13         }
14     }
15 }