PA7493

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

5 of 7

www.unisonic.com.tw

QW-R502-113.C

FUNCTION DESCRIPTION

POWER SUPPLY

The UTC PA7493 operating voltage range is from 3V to 6V. In general, the 5V operating voltage is recommended.

When the supply voltage less than 3V, the IC can work properly but the distortion will rise. The higher stand-by

current consumption will rise the chip surface temperature after the operating voltage over 6.5V.

SHUTDOWN

At the shutdown mode, the total current consumption is less than 0.7μA, and all of the input/output pins no voltage

output. The chip is back to the normal operation when the SHUTDOWN pin sets to GND.

SHUTDOWN PIN

OUTPUT STATE

SHUTDOWN ON

GND

Normal

INPUT GAIN ADJUST

The output gain of the UTC PA7493 can be adjusted by the external resistor. 0dB gain setting is recommended in

can be increased to get the proper volume. The minimum value of the input series resistance is 10KΩ for the modest

input impedance.

To make sure the input stage not distorted by overload, please confirm the input signal level. For the gain set

please refer the following table:

Operating Voltage

Input Gani=-6db

Input Gain=0db

Input Gani=+6db

SE/BTL MODE SWITCHING

The UTC PA7493 has two output modes, SE(Single-Ended) or BTL(Bridge-Tied Load). To drive a speaker load,

set to the BTL mode is recommended for getting the more power output. Driving a headphone load, we suggest

setting to SE mode and turn-off the un-work amplifier to decrease the stand-by power consumption. Switching

between the SE and BTL modes is controlled by the SE/BTL pin, please refer the following table:

SE/BTL

MODE

SE

GND

BTL

CLICK AND POP SURPPRESS

A power amplifier uses single supply voltage may cause noises on the output port during the power-on period. It is

because of the output DC potential level needs time to stable on 1/2Vcc, the period is relative with the capacitor on

the BYPASS pin. The higher capacitor value will extend the stable time and also suppress the noise during the

power-on period. At the supply voltage is 5V and the capacitor is 2.2μF, the stable time is around 300ms. The value

of the BYPASS capacitor also relatives with the DC blocking capacitor connected at the input terminal. In general

condition the time constant of DC blocking capacitor should be less than the CB stable time. Recommend parts

values please refer the application circuit.