ADC0808/ADC0809 8-Bit
μP
Compatible A/D Converters with 8-Channel Multiplexer
March 2007
ADC0808/ADC0809
8-Bit
μP
Compatible A/D Converters with 8-Channel
Multiplexer
General Description
The ADC0808, ADC0809 data acquisition component is a
monolithic CMOS device with an 8-bit analog-to-digital con-
verter, 8-channel multiplexer and microprocessor compatible
control logic. The 8-bit A/D converter uses successive ap-
proximation as the conversion technique. The converter fea-
tures a high impedance chopper stabilized comparator, a
256R voltage divider with analog switch tree and a successive
approximation register. The 8-channel multiplexer can direct-
ly access any of 8-single-ended analog signals.
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 ADC0808, ADC0809 has been optimized
by incorporating the most desirable aspects of several A/D
conversion techniques. The ADC0808, ADC0809 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 suit-
ed to applications from process and machine control to con-
sumer and automotive applications. For 16-channel multi-
plexer with common output (sample/hold port) see ADC0816
data sheet. (See AN-247 for more information.)
Features
■
Easy interface to all microprocessors
■
Operates ratiometrically or with 5 V
DC
or analog span
■
■
■
■
■
■
adjusted voltage reference
No zero or full-scale adjust required
8-channel multiplexer with address logic
0V to V
CC
input range
Outputs meet TTL voltage level specifications
ADC0808 equivalent to MM74C949
ADC0809 equivalent to MM74C949-1
Key Specifications
■
■
■
■
■
Resolution
Total Unadjusted Error
Single Supply
Low Power
Conversion Time
8 Bits
±�½ LSB and ±1 LSB
5 V
DC
15 mW
100 μs
Block Diagram
567201
See Ordering
Information
© 2007 National Semiconductor Corporation
5672
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
