FS9922-DMM4 is a high performance, low power consumption and 3 6/7 digits (6000 Counts) dual Analog to Digital Converter with a built-in microprocessor. It includes a 8 bits microprocessor, low noise and the OPAMP of high stability, AC rectifier OPAMP, voltage doubling and regulated voltage, highly regulated bandgap, auto measurement switch and function control circuit, buzzer driver circuit, clock oscillation circuit, backlight display control circuit, LCD driver circuit and so on. Built-in dual Analog to Digital Converter , one is a high accuracy ADC for main measurement; the other is a high speed ADC whose measurement result shows by a 61 segment analog section bar that can respond fast, the analog indication owns the property of immediate response and can provide the fast measurement and monitoring of instant signals. With the microprocessor, FS9922-DMM4 can do the logic function control via the I/O ports. By selecting the codes of MEA1〜MEA5 pins can realize various functions during measurement. By triggering the keys of the settings of SELECT, RANGE, REL/RS232, HZ/DUTY, HOLD/LIGHT, MAX/MIN keys, you can realize the functions of function switch, measurement mode select, relative value measurement, frequency/duty cycle measurement, reading hold, MAX/MIN value hold, backlight display, RS232 output and so on. With the auto power off function, when there is no action on the mode switch or keys of the meter within 15 minutes, the system will enter into the sleep mode automatically to save the power. This function can also be cancelled during use. FS9922-DMM4 has LCD driver circuits, which is designed for driving LCD. FS9922-DMM4 is made by the large integrated circuit technology, and therefore greatly rises up the reliability of the product. It makes the design simple, the volume small, low power consumption by using 3V power source, and convenient to use the power supply of battery, especially suitable for the application on the palm mode meter. FS9922-DMM4 is a microprocessor-embedded and multifunctional measuring dual ADC; fewer external components added can form a high accuracy, multifunctional and low cost measuring