PA4401

Click-Pop Suppression Device

ANALOG PRODUCTS DIVISION

561 E. Elliot Road #175, Chandler, AZ 85225 Tel: (480) 539-2900. Fax: (602) 414-5141

www.protekanalog.com

95025. Rev.0. 05/2008

NOT FOR USE IN LIFE SUPPORT SYSTEMS

Pre

Amp

+

+

Pre

Amp

IN

OUT

IN

OUT

CONNECTION DIAGRAM

The PA4401 will be placed after the pre-amplifier and before the output bypass capacitors.

Figure 4: Typical Connection Configuration for PA4401

STARTUP

and controls the ramp rate of the DC bias voltage going to the +ve terminal of the bypass capacitor. The ramping behavior of the

device can be controlled by an external capacitor. This startup operation is shown in figure 5.

SHUTDOWN

At Shutdown, The PA4401 detects a “power fail” condition and the control switches are turned off, opening the connection

between INx and OUTx providing a discharge path through an internal 100KΩ resistor for the bypass capacitor. The time

constant of the internal resistor and by-pass capacitor, allows for a slow discharge, which will prevent any audible “pop”

appearing at the system output. This shutdown operation is shown in figure 5.

Figure 5: Power-Up and Power-Down sequences and waveforms with PA4401

t

t

0

0

<50mV

Start-up “pop”

time

mSec

50mS

50mS

<50mV

shutdown “pop”

PA4401 slows

down transition at

coupling capacitor

Power Supply Waveform

Bypass capacitor input plate

System output