1W Stereo Audio Amplifier Kit

SKU
QK139
In stock
$12.95
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Overview
Uses a TDA7053A to create an integrated stereo power amplifier with volume control. 5 - 18VDC

The TDA7053A is an integrated stereo audio power amplifier with DC volume control in a 16-pin dual-in-line plastic package. It is designed for use in TVs and monitors but is also suitable for battery-operated equipment. The circuit used is straight out of the data book. PCB dimensions are a tiny 43mm x 40mm (1.7" x 1.6").
TDA7053A SPECIFICATIONSStereo 1 Watt Audio Amplifier Kit With Volume Control


4.5 - 18V supply voltage range
 1.5A max non-repetitive peak output current
 1.25A max repetitive peak output current
 1.1W output power using 6V supply into 8 load
(THD = 10%)

 20k internal input impedance 210uV noise output voltage
 20Hz to 300kHz bandwidth (typical) at 1 dB
The kit is constructed on single-sided printed circuit board. Protel Autotrax & Schematic were used.

CONSTRUCTION

Start with the two resistors followed by the small monobloc capacitor. Next comes the IC socket with the electrolytic and polyester capacitors last. Be careful to get the electrolytic capacitors in the right way around. The positive lead is marked on the overlay. The negative lead is marked on the body of the capacitor. Solder the power and audio cables (supplied by you) directly to the pads provided on the PCB.

CIRCUIT DESCRIPTION

All the work is done internally in the IC. The internal circuit consists of a differential input stage with integrated DC volume control, two class AB output stages and a stabiliser circuit. Resistors R1 and R2 provide a DC input impedance to ground. The input signal is AC coupled into the amplifier via capacitors C3 and C4. The output stages are a BTL (Bridge Tied Load) configuration, resulting in increased output power at low supply voltages. The gain of each amplifier channel is controlled by the DC voltage level on pins 2 and 8. This voltage is derived from the DC supply using a simple voltage divider network of resistor R3 and potentiometer VR1. Capacitor C5 across the potentiometer provides power supply decoupling of the volume control inputs. If the DC volume control voltage falls below 0.4V the chip will switch to mute mode. The maximum voltage gain of the amplifier is internally fixed at 40.5dB. The DC volume control has a logarithmic characteristic. The total gain can be controlled from +40.5 to 33 dB. Due to the BTL output configuration the outputs are floating with respect to ground.
Therefore the outputs of the amplifier should never be connected to ground. Capacitors C1 and C2 provide power supply decoupling.