描述：The EVAL-ADMP421Z is an bottom ported digital output MEMS microphone evaluation board of 13mm × 18mm size. It is a simple evaluation board that allows quick evaluation and performance of the ADMP421 MEMS microphone. The EVAL-ADMP421Z has a dual row 12 pin, 0.1 inch spaced header for access to all microphone pins. The EVAL-ADMP421Z is designed to plug directly into Connector J6 on the EVAL-ADAU1761Z evaluation board. The Evaluation board contains factory installed 0.1 μF capacitor, C1, is a bypass capacitor that reduces supply noise and ensures proper microphone operation. The ADMP421 is a low cost, low power, digital output bottom ported omni directional MEMS microphone. The ADM421 consists of a MEMS microphone element, an output amplifier and a 4th order sigma delta modulator. The digital interface allows for the PDM (Pulse Density Modulated) output of two microphones to be time multiplexed on a single data line using a single clock. . The 12 pin header connects all microphone signals directly to EVAL-ADAU1761Z or EVAL-ADAU1361Z . ADMP421 is a small and thin 3mm × 4mm × 1mm surface mount package IC . ADMP421 has a high SNR of 61dBA and high sensitivity of -26dBFS, useful for far field applications . It has flat frequency response from 100Hz to 15kHz . It has low current consumption of <650μA . It provides sleep mode for extended battery life . It provides high PSR of 80dBFS . It exhibits fourth-order Σ-Δ modulator . It gives digital PDM output . EVAL-ADMP421Z board is RoHS compliant