The ADuC7019/20/21/22/24/25/26/27/28/29 are fully integrated，1 MSPS， 12-bit data acquisition systems incorporating high performance multichannel ADCs， 16-bit/32-bit MCUs， and Flash?/EE memory on a single chip。The ADC consists of up to 12 single-ended inputs。An additional four inputs are available but are multiplexed with the four DAC output pins。The four DAC outputs are available only on certain models (ADuC7020，ADuC7026，ADuC7028，and ADuC7029)。However， in many cases where the DAC outputs are not present，these pins can still be used as additional ADC inputs，giving a maximum of 16 ADC input channels。 The ADC can operate in single-ended or differential input mode。The ADC input voltage is 0 V to VREF。A low drift band gap reference，temperature sensor，and voltage comparator complete the ADC peripheral set.Depending on the part model，up to four buffered voltage output DACs are available on-chip。The DAC output range is programmable to one of three voltage ranges。