TLV320AIC1103

SLAS356 − DECEMBER 2001

4

www.ti.com

functional description

power on/reset

The power for the various digital and analog circuits is separated to improve the noise performance of the

device. An external reset must be applied to the active low RESET terminal to assure reset upon power on. After

the initial power-on sequence the TLV320AIC1103 can be functionally powered up and down by writing to the

mode option. The PWRUPSEL function allows the VBAP to power up in the default mode and allows use without

a microcontroller.

reference

A precision band gap reference voltage is generated internally and supplies all required voltage references to

operate the transmit and receive channels. The reference system also supplies bias voltage for use with an

electret microphone at terminal MBIAS. An external precision resistor is required for reference current setting

at terminal REXT.

control interface

six control registers:

There are two power-up modes which may be selected at the PWRUPSEL terminal:

interface. The programmable functions are fixed in the default modes.

phase-locked loop

The internal digital filters and modulators require a 10.24-MHz clock that is generated by phase locking to the

2.048-MHz master clock input.

PCM interface

The PCM interface transmits and receives data at the PCMO and PCMI terminals respectively. The data is

transmitted or received at the PCMCLK speed once every PCMSYN cycle. The PCMCLK can be tied directly

to the 2.048-MHz master clock (MCLK). The PCMSYN can be driven by an external source or derived from the

master clock and used as an interrupt to the host controller.

microphone amplifiers

The microphone input is a switchable interface for two differential microphone inputs. The first stage is a low-

noise differential amplifier that provides a gain of 23.5 dB. The second stage amplifier has a selectable gain of

0 dB or 12 dB.