CMA-4544PF-W Expansion Board with Microphone and MAX9814

The CMA-4544PF-W expansion board is equipped with an electret microphone (with a frequency range of 20 Hz to 20 KHz) and an appropriate amplifier. The special MAX9814 chip from Maxim was developed to amplify electret microphones in situations where sound volume is unknown. The adaptive gain control (AGC) embedded in the amplifier suppresses loud noises nearby to prevent clipping and distortion while enhancing distant, softer sounds. This amplifier offers several options that can be configured on the expansion board.

Specifications:

• Power Supply Voltage: 2.7V-5.5V @ 3mA current
• Output: 2Vpp at 1.25V bias
• Frequency Response: 20Hz - 20KHz
• Programmable attack and release ratios
• Automatic gain, selectable maximum gain of 40dB, 50dB, or 60dB
• Low noise density 30nV
• Low THD: 0.04% (typical)
• Low power in shutdown mode
• Built-in 2V low-noise microphone bias
• -40°C ~ +85°C extended temperature range