Datasheet

MAX9867

Ultra-Low Power Stereo Audio Codec

42 ______________________________________________________________________________________

Digital Microphone Input

The MAX9867 can accept audio from up to two digital

microphones. When using digital microphones, the left

analog microphone input is retasked as a digital micro-

phone input. The right analog microphone input is still

available to allow a combination of analog and digital

microphones to be used. Figure 6 shows the digital

microphone interface timing diagram. See Table 15.

Table 15. Digital Microphone Input Register

ADDRESS

Microphone MICCLK DIGMICL DIGMICR 0 0 0 0 0x15

BITS FUNCTION

MICCLK

Digital Microphone Clock

00 = PCLK/8

01 = PCLK/6

10 = Reserved

11 = Reserved

Digital Left/Right Microphone Enable

DIGMICL DIGMICR Left ADC Input Right ADC Input

0 0 ADC input mixer ADC input mixer

Line input (left analog

microphone unavailable)

Right digital microphone

1 0 Left digital microphone ADC input mixer

1 1 Left digital microphone Right digital microphone

DIGMICL/DIGMICR

Note: The left analog microphone input is never available when DIGMICL or DIGMICR = 1.

DIGMICCLK

DIGMICDATA

SU, MIC

HD, MIC

SU, MIC

HD, MIC

LEFT RIGHT LEFT RIGHT

1/f

MICCLK

Figure 6. Digital Microphone Timing Diagram