PA7375

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

5 of 10

www.unisonic.com.tw

QW-R107-058.B

TYPICAL APPLICATION INFORMATION

High Application Flexibility

To avoid phase inconveniences causing sound alterations especially during the reproduction of low frequencies.

The polarity of the speakers driven by the inverting amplifier must be reversed respect to those driven by non

inverting channels when working in single ended conditions.

Easy Single Ended to Bridge Transition

The change from single ended to bridge configurations is made by a short circuit across the inputs.

Gain Internally Fixed to 20dB in Single Ended, 26dB in Bridge

The function advantages: save component, PCB space and optimize output noise, supply voltage rejection and

distortion

Silent Turn On/Off and Muting/Stand-by Function

At turn-on the device stays in muting condition for a time. The device outputs becomes insensitive to any kinds

of signal that may be present at the input terminals while in muting.

STAND-BY DRIVING

The stand by pin cannot be directly driven by a voltage source whose current capability is higher than 5mA. A

series resistance has been inserted to limit the current at this pin and to smooth down the stand-by ON/OFF

transitions. To ensure correct turn-on, a capacitor of at least 100nF from pin 7 to S-GND, with no resistance in

between.

BUILT–IN SHORTCIRCUIT PROTECTION

To assure correct operation for the device itself and for the loudspeaker, a SOFT SHORT condition is signaled

out during the TURN-ON PHASE .

That acts in a way to avoid that the device is turned on (by ST-BY) when a resistive path (less than 16 Ω) is

present between the output and GND. When a current higher than 5mA is flowing into the ST-BY pin the

involved circuitry is normally disabled.

That extra function becomes particularly attractive when, in the single ended configuration

Diagnostics Facility

The IC is equipped with a diagnostic circuitry able to detect the information(clipping in the output signal,

open collector output (pin 10) through a current sinking when the event is detected.

Clipping Detection Waveforms

When a certain distortion level is reached at any of the outputs a current sinking at pin 10 is triggered.

Whenever the amplifier is overdriven this function allows gain compression possibility.

Thermal Shutdown

In this case the output 10 will signal the proximity of the junction temperature to the shutdown threshold.

Typically current sinking at pin 10 will start ~10°C before the shutdown threshold is reached.