
ADC0816/ADC0817
8-Bit μP Compatible A/D Converters
with 16-Channel Multiplexer
General Description
The ADC0816, ADC0817 data acquisition component is a
monolithic CMOS device with an 8-bit analog-to-digital con-
verter, 16-channel multiplexer and microprocessor compat-
ible control logic. The 8-bit A/D converter uses successive
approximation as the conversion technique. The converter
features a high impedance chopper stabilized comparator, a
256R voltage divider with analog switch tree and a succes-
sive approximation register. The 16-channel multiplexer can
directly access any one of 16-single-ended analog signals,
and provides the logic for additional channel expansion. Sig-
nal conditioning of any analog input signal is eased by direct
access to the multiplexer output, and to the input of the 8-bit
A/D converter.
The device eliminates the need for external zero and
full-scale adjustments. Easy interfacing to microprocessors
is provided by the latched and decoded multiplexer address
inputs and latched TTL TRI-STATE
outputs.
The design of the ADC0816, ADC0817 has been optimized
by incorporating the most desirable aspects of several A/D
conversion techniques. The ADC0816, ADC0817 offers high
speed, high accuracy, minimal temperature dependence, ex-
cellent long-term accuracy and repeatability, and consumes
minimal power. These features make this device ideally
suited to applications from process and machine control to
consumer and automotive applications. For similar perfor-
mance in an 8-channel, 28-pin, 8-bit A/D converter, see the
ADC0808, ADC0809 data sheet. (See AN-258 for more in-
formation.)
Features
n
Easy interface to all microprocessors
n
Operates ratiometrically or with 5 V
DC
or analog span
adjusted voltage reference
n
16-channel multiplexer with latched control logic
n
Outputs meet TTL voltage level specifications
n
0V to 5V analog input voltage range with single 5V
supply
n
No zero or full-scale adjust required
n
Standard hermetic or molded 40-pin DIP package
n
Temperature range 40C to +85C or 55C to +125C
n
Latched TRI-STATE output
n
Direct access to “comparator in” and “multiplexer out” for
signal conditioning
n
ADC0816 equivalent to MM74C948
n
ADC0817 equivalent to MM74C948-1
Key Specifications
n
Resolution
n
Total Unadjusted Error
n
Single Supply
n
Low Power
n
Conversion Time
8 Bits
±
1
2
LSB and
±
1 LSB
5 V
DC
15 mW
100 μs
Block Diagram
TRI-STATE
is a registered trademark of National Semiconductor Corporation.
DS005277-1
June 1999
A
1999 National Semiconductor Corporation
DS005277
www.national.com