Product Info

LTE Standard Module Series

EC25 Mini PCIe Hardware Design

EC25_Mini_PCIe_Hardware_Design 33 / 80

PCM_CLK

PCM_SYNC

PCM_DOUT

MSB

LSB

PCM_DIN

125us

MSB

1 2

3231

LSB

Figure 8: Timing in Auxiliary Mode

Clock and mode can be configured by AT command, and the default configuration is master mode using

short frame synchronization format with 2048kHz PCM_CLK and 8kHz PCM_SYNC. In addition, EC25

Mini PCIe’s firmware has integrated the configuration on some PCM codec’s application with I2C interface.

Please refer to document [2] for details about AT+QDAI command.

The following figure shows a reference design of PCM interface with an external codec IC.

PCM_DIN

PCM_DOUT

PCM_SYNC

PCM_CLK

I2C_SCL

I2C_SDA

Codec

Module

1.8V

2.2K

BCLK

DACIN

ADCOUT

SCLK

SDIN

BIAS

MIC_BIAS

MIC+

MIC-

SPKOUT+

SPKOUT-

Figure 9: Reference Circuit of PCM Application with Audio Codec

Digital audio (PCM) function is only supported on Telematics version.

NOTE