GENERAL DEscriptION

The SGM4822/SGM4825 (single-input) and SGM4823/SGM4826 (dual-input) are low noise, low power, rail-to-rail, fixed-gain microphone amplifiers with integrated bias. The SGM4822/SGM4823 support power supply voltage from 3.3V to 5.5V and the SGM4825/SGM4826 support wide power supply voltage from 2.7V to 5.5V. The devices are suitable for portable audio applications. They feature low THD+N = 0.009% in active mode, 2.6MHz bandwidth and forced shutdown mode.

The SGM4822/SGM4823 power-saving features include automatic switching between low power monitor mode and low noise active mode, and the devices also provide latched push-pull output to wake up external MCU in sleeping mode. Two inputs of the SGM4823/SGM4826 allow two microphones to be multiplexed into one output.

The devices operate over an ambient temperature range of -40℃ to +85℃.

FEATURES

• Very Low Noise: 30nV/√Hz at 1kHz, Gain = 20dB

• Very Low THD+N: 0.009%, Gain = 20dB

• Wide Supply Voltage Range: 3.3V to 5.5V

• Low Current:

  0.1μA in Forced Shutdown Mode

  4μA in Monitor Mode at VCC = 3.3V

  660μA in Active Mode

• Low Noise Microphone Bias Voltage: 2.3V

• Rail-to-Rail Outputs

• 20dB Fixed-Gain

• Automatic Switching between Low Power Monitor Mode and Low Noise Active Mode 

• Latched Push-Pull Output to Wake Up External MCU in Sleeping Mode

• -40℃ to +85℃ Operating Temperature Range

APPLICATIONS

Laptop Computers

Smart Phones

Digital Cameras

VCRs