2. Working principle: MIC circuit is mainly composed of microphone and microphone power biasing
circuit. MIC1 switches the recorded external voice signals to electrical signal, through C61 coupling,
output to ADC circuit of PNX0101 to converse analog electric signal to digital electric signal and form
WAV files after encoding of software to save in FLASH.
In the circuit, R59, R60, Q9 and C60 are triode voltage stabilizing system, which provides stable
power bias for microphone, R61 is the bias resistor of microphone.
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Summary of Contents for X21
Page 1: ...service manual X21 RU ...
Page 42: ...3 L1 1 8V energy storage waveform diagram 4 LCD_CS wabeform 5 LCD_D C waveform diagram 37 ...
Page 43: ...6 LCD_RESET 7 LCD_WR waveform diagram 8 LCD_RD waveform diagram 38 ...
Page 45: ...12 LCD_DB3 waveform diagram 13 LCD_DB4 waveform diagram 14 LCD_DB5 waveform diagram 40 ...
Page 46: ...15 LCD_DB6 waveform diagram 16 LCD_DB7 waveform diagram 17 IREF waveform diagram 41 ...
Page 47: ...18 VCOMH waveform diagram 42 ...
Page 66: ...Chapter Cinque PCB board Circuit diagram Section One PCB board X21 PCB Board 61 ...