Here the schematic diagram of mic preamplifier which build based on operational amplifier TC251. The TLC251 is operating in low bias. The circuit works with only 1.5 V supply draws electric current of only 10 mA, so the battery operation will be prefered. Circuit frequency response is 3dB, 27 Hz to 4.8 kHz.
The TLC251 are low-cost, low-power programmable operational amplifiers designed to operate with single or dual power supplies. Because the input common-mode range extends to the negative rail and the power consumption is very low, this chip is ideally suited for battery-powered or energy-conserving applications. A bias-select pin can be used to program one of three ac performance and power-dissipation levels to suit the application. The series features operation down to a 1.4V supply and is stable at unity gain.
Download the TLC251 datasheet document from the following link:
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