General Description

The ADC0801, ADC0802, ADC0803, ADC0804 and

ADC0805 are CMOS 8-bit successive approximation A/D

converters that use a differential potentiometric

ladder—similar to the 256R products. These converters are

designed to allow operation with the NSC800 and INS8080A

derivative control bus with TRI-STATE output latches directly

driving the data bus. These A/Ds appear like memory locations

or I/O ports to the microprocessor and no interfacing

logic is needed.

Differential analog voltage inputs allow increasing the

common-mode rejection and offsetting the analog zero input

voltage value. In addition, the voltage reference input can be

adjusted to allow encoding any smaller analog voltage span

to the full 8 bits of resolution.

Features

n Compatible with 8080 μP derivatives—no interfacing

logic needed - access time - 135 ns

n Easy interface to all microprocessors, or operates “stand

alone”

n Differential analog voltage inputs

n Logic inputs and outputs meet both MOS and TTL

voltage level specifications

n Works with 2.5V (LM336) voltage reference

n On-chip clock generator

n 0V to 5V analog input voltage range with single 5V

supply

n No zero adjust required

n 0.3 standard width 20-pin DIP package

n 20-pin molded chip carrier or small outline package

n Operates ratiometrically or with 5 VDC, 2.5 VDC, or

analog span adjusted voltage reference