PGA2320

SBOS312B − JULY 2004 − REVISED DECEMBER 2004

www.ti.com

7

GENERAL DESCRIPTION

The PGA2320 is a stereo audio volume control. It may be

used in a wide array of professional and consumer audio

equipment. The PGA2320 is fabricated in a mixed-signal

BiCMOS process in order to take advantage of the

superior analog characteristics that the process offers.

The heart of the PGA2320 is a resistor network, an analog

switch array, and a high-performance bipolar op amp

stage. The switches are used to select taps in the resistor

network that, in turn, determine the gain of the amplifier

stage. Switch selections are programmed using a serial

control port. The serial port allows connection to a wide

variety of host controllers. Figure 1 shows a functional

block diagram of the PGA2320.

POWER-UP STATE

On power up, all internal flip-flops are reset. The gain byte

or mute condition. The gain will remain at this setting until

the host controller programs new settings for each channel

via the serial control port.

ANALOG INPUTS AND

OUTPUTS

The PGA2320 includes two independent channels,

referred to as the left and right channels. Each channel has

a corresponding input and output pin. The input and output

pins are unbalanced, or referenced to analog ground

It is important to drive the PGA2320 with a low source

impedance. If a source impedance of greater than 600

Ω is

used, the distortion performance of the PGA2320 will

begin to degrade.

MUX

Serial

Control

Port

MUX

ZCEN

CS

SCLK

SDI

SDO

MUTE

V

V

V

AGNDL

AGNDR

V

V

V

12

13

4

5

11

7

3

6

2

1

8

14

16

15

10

9

8

8

8

8

Figure 1. PGA2320 Block Diagram