PGA4311

SBOS230A – MARCH 2002 – REVISED JUNE 2002

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TYPICAL CHARACTERISTICS (Cont.)

At TA = +25°C, VA+ = +5V, VA– = –5V, VD+ = +5V, RL = 100kΩ, CL = 20pF, BW measure = 10Hz to 20kHz, unless otherwise noted.

(NOTE: All plots taken with PGA4311 A–Grade.)

GENERAL DESCRIPTION

The PGA4311 is a four-channel audio volume control.

It may be used in a wide array of professional and

consumer audio equipment. The PGA4311 is fabricated

in a sub-micron CMOS process.

The heart of the PGA4311 is a resistor network, an analog

switch array, and a high-performance 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. See Figure 1 for a functional block

diagram of the PGA4311.

POWER–UP STATE

On power up, “power-up reset” is activated for about

100ms during which the circuit is in hardware MUTE state

and all internal flip-flops are reset. At the end of this period,

the offset calibration is initiated without any external signals.

Once this has been completed, the gain byte value for all

tion. The gain will remain at this setting until the host con-

troller programs new settings for for each channel via the

serial control port.