MX93002

The MX93002 PCM CODEC integrates key functions of the analog-front-end of DAM (with Digital Speakerphone) related products into an integrated circuit. The MX93002 PCM CODEC is especially powerful when applied to some DAM models which are intended to meet different countries' specifications in the same system hardware. User can achieve this goal by simply setting control firmware. This benefit will help DAM system makers to save developing time and R&D resources.

The MX93002 has two A/D, D/A converters so as to meet the requirement of the digital speakerphone application.The on-chip digital filters, which are carried out with 16-bit and 2's complement format, are used to get required frequency response of a PCM CODEC. The CODEC can support 8-bit u/A law and linear data format. For the latter, it is 16-bit format with 14-bit resolution.

Before the A/D digitizing the voice-band analog signal into digital format, the analog signal can be processed by a built-in Automatic Level Control (ALC) and PRE-Programmable Gain Amplifier (PRE-PGA). The ALC circuit controls the signal level about 1.2Vpp and AD1-PGA can provide 0 ~ 18dB gain to get more larger signal. The PRE-PGA circuit is used to control the gain of different sources like MIC, AUX1 or LIN input.

After the digital data is converted into analog signal by D/A converter, a fully differential line driver and speaker
driver are supported to drive the telephone line and 8W speaker directly without needing any external amplifiers. Besides, the analog signal can be monitored by passing the on-chip volume control or external volume control.

The MX93002 supports many switches as well. User can program the control registers of the PCM CODEC to accomplish all specific operations of DAM (with digital speakerphone function) related products.

In order to let MCU (Micro controller) easily Read/Write the control registers of the MX93002, the sampling clock of the serial control data is clocked by external SCLK clock and synchronized by SDENB, where SDENB signal is coming from the MCU output port by detecting one of the rising edge of external SCLK clock.