The ADC0804 is a CMOS 8-bit successive-approximation analog-to-digital converter that uses a modified potentiometric (256R) ladder. The ADC0804 is designed to operate from common microprocessor control buses, with the 3-state output latches driving the data bus. The ADC0804 can be made to appear to the microprocessor as a memory location or an I/O port. Detailed information on interfacing to most popular microprocessors is readily available from the factory. A differential analog voltage input allows increased common-mode rejection and offset of the zero-input analog voltage value. Although REF/2 is available to allow 8-bit conversion over smaller analog voltage spans or to make use of an external reference, ratiometric conversion is possible with REF/2 open. Without an external reference, the conversion takes place over a span from VCC to ANLG GND. The ADC0804 can operate with an external clock signal or, with an additional resistor and capacitor, can operate using an on-chip clock generator.