CDMA BAP

CX20470

101106A

Skyworks – Preliminary

5

August 24, 2000

Proprietary Information and Specifications are Subject to Change

Audio CODEC Section

The CODEC serves as an interface between a voice device and a

digital processor system. The CODEC provides a bi-directional

interface between voice/audio and a digital system processor. It

receives audio signals from sources such as microphones,

digitizes the signals, and outputs them to a host processing

system. The CODEC receives digital signals from the digital

processing system (MSM ASIC or equivalent), converts the signal

to analog, and outputs the signal to a device such as an earpiece

or a speaker.

As shown in Figure 5, CODEC operations can be divided into four

groups: transmit (ADC) channel, receive (DAC) channel, timing

and control, and power control.

CODEC Transmit Section. The transmit section is designed to

interface directly with a microphone and/or an external audio

source at the same time. The microphone input or external source

signal can be selected as the audio input signal.

The input signal is buffered and amplified with a provision to set

the amplifier gain to accommodate a range of signal input levels.

The amplified signal is then anti-aliased and bandpass filtered and

applied to the input of a 14-bit linear A/D converter. The digital

converted data is then clocked out as a serial data stream

(PCMOUT) to the digital system processor.

CODEC Receive Section. The receive section collects a frame of

serial data on the PCMIN and converts it to the analog signal

through a linear D/A converter. The analog converted signal is

then lowpass filtered to provide out-of-band rejection and

smoothing. The filtered signal is sent to the speaker or the line

driver amplifier. Both amplifiers have a differential output with

adjustable gain control.

CODEC Configuration and Control Interface Section. CODEC

operation mode and configuration control registers can be easily

programmed directly from a digital system processor through an

interface.

Electrical and Mechanical Specifications

Signal pin assignments and functional pin descriptions are

described in Table 1 (100-pin

µBGA) and Table 2 (56-pin LGA).

The absolute maximum ratings of the CX20470 are provided in

Table 3. The recommended operating conditions are specified in

Table 4. Electrical specifications are provided in Table 5.

Tables 6 through 9 specify input and output signal levels and

electrical characteristics. A system block diagram is provided in

Figure 4 and an audio CODEC block diagram is presented in

Figure 5.

Package dimensions for the CX20470 are shown in Figure 6

(100-pin

µBGA) and Figure 7 (56-pin LGA).

Electrostatic Discharge (ESD) Sensitivity

The CX20470 is a Class 1 device. The following ESD precautions

are required:

•

Protective outer garments.

•

Handle device in ESD safeguarded work area.

•

Transport device in ESD shielded containers.

•

Monitor and test all ESD protection equipment.

Treat the CX20470 BAP as extremely sensitive to ESD since ESD

sensitivity has not yet been determined for this device.