MEMS 麦克风接口

DCC-1448是一款用1位PDM（脉冲密度调制）输出测量MEMS（微电子机械系统）麦克风和其他设备的接口。它跟SoundCheck®之类的音频测试系统相结合使用，成为MENS数字麦克风定量测试和测量的完整解决方案。

DCC-1448将数字MEMS麦克风1位PDM输出转换为一个被音频测试系统所接受的24位，48赫兹PCM信号。这样就可以测量典型的麦克风特性，如频响，灵敏度和方向性。DCC-1448还可以测量MEMS麦克风独特的特性。其中包括了一个可以编程的时钟来测量采样率相关性能，一个程控电源来测量电压电源相关性能，以及一个电源抑制减值发生器来测量电源抑制（PSR）/电源抑制率（PSRR）. 该仪器不产生任何声响，所以可以用在消声室里面，由于MEMS麦克风只能驱动一个较短的电缆线，这个特性非常有用。

Features include:

• Control and configuration within SoundCheck, via USB, or using front panel

• Straightforward operation – the data input, clock, Vdd, and ground interface are on the front panel, and the rear panel contains USB and SPIDIF interfaces for connection to the computer’s audio interface

• Simultaneous SPDIF and USB digital audio output are compatible with most test equipment with digital audio inputs and both Mac and Windows computers.

• Programmable clock typically operates as the master, but can also operate in slave mode (e.g. for measuring performance of a PDM signal generator, synching multiple microphones in an array, or where use of an external clock is preferred)

• Conversion occurs entirely in the digital domain

• Can interface with two microphones simultaneously. This is useful for testing finished product that contains multiple microphones or for characterizing matched pairs. When using two microphones all connections are shared, including the data line; one microphone transmits data on rising edge of the clock pulse and the other on the falling edge of the clock pulse. Internally to the instrument the decoded data is sent to the left and right channels of the SPDIF and USB outputs. When using two microphones the L/R selection line of one microphone is tied to ground and the other is tied to Vdd.

新推出的PQC-3048 MEMS数字麦克风接口是是专为大批量生产线测试MENS麦克风所设计的。它在数字领域内把被测设备返回来的1位音频数据转换为48kHz采样率的24位PCM音频，并且提供测试所需的时钟信号和直流电源。
Features include:

• Control from within SoundCheck or via USB virtual com port using a command line utility

• Just two connectors: USB for power and control, and a pluggable phoenix connector to interface with the device under test

• Rugged and compact

• Simple to use with minimal potential for incorrect operation

• 2个麦克风可以同时连接，并可以连接多个仪器到同一台电脑同时测试多个设备。

• Uses the same 1-bit PDM to multi-bit PCM conversion algorithm as the DCC-1448 MEMS interface, ensuring that measurements made with one can be reproduced with the other
  Low cost – less than half the price of the DCC-1448