Cirrus Logic CRD48L10 - Manual (Page 40)

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Chapter 12
Using Analog MEMS Microphones
When shipped, the CRD48L10-4in4out is configured to work with ECM microphones. The CS472L73 provides a bias
voltage of +2.0 V to +2.75 V to the MIC1 and MIC2 inputs through the J8 and J9 jumpers. The exact bias voltage is
configurable through the MIC_BIAS_CTRL bit within the CS42L73 registers. The AMEMS microphone provides its own
bias level, so J8 and J9 need to be removed to use the AMEMS Microphone module.
Figure 12-1. MIC Bias Jumpers
The CRD48L10-4in4out includes two styles of Analog MEMS daughter cards. AMEMS BRD 1 and AMEMS BRD 2 are
footprint compatible with the ADMP504. AMEMS BRD 3 and AMEMS BRD 4 are footprint compatible with the ADMP401.
The AMEMS daughter cards are shown in
Fig. 12-2 .
Figure 12-2. AMEMS Daughter Cards
Microphones are not mounted on these boards. The customer can attach any microphone matching the footprints
provided. Once microphones have been mounted on daughter cards, they can be wired to the AMEMS HDMI daughter
card, as shown in
Fig. 12-3 , and then connected to the CRD48L10-4in4out using a standard HDMI Type A > HDMI Type
D (Micro) cable, as shown in Fig. 12-4 .
Table 12-1. MIC Bias Jumpers
Header Voltage Signal
J8 +2.0 V – +2.75 V MIC1 Bias Voltage from CS42L73 (PIN1), MIC1 (PIN2)
J9 +2.0 V – +2.75 V MIC2 Bias Voltage from CS42L73 (PIN1), MIC2 (PIN2)