1FEATURES
2• Easy Interface to All Microprocessors
• Operates Ratiometrically or with 5 VDC or
Analog Span Adjusted Voltage Reference
• No Zero or Full-Scale Adjust Required
• 8-Channel Multiplexer with Address Logic
• 0V to VCC Input Range
• Outputs meet TTL Voltage Level Specifications
• ADC0808 Equivalent to MM74C949
• ADC0809 Equivalent to MM74C949-1

KEY SPECIFICATIONS
• Resolution: 8 Bits
• Total Unadjusted Error: ±½ LSB and ±1 LSB
• Single Supply: 5 VDC
• Low Power: 15 mW
• Conversion Time: 100 μs

DESCRIPTION
The ADC0808, ADC0809 data acquisition component
is a monolithic CMOS device with an 8-bit analog-to-
digital converter, 8-channel multiplexer and
microprocessor compatible 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
successive approximation register. The 8-channel
multiplexer can directly 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, excellent 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 16-
channel multiplexer with common output (sample/hold
port) see ADC0816 data sheet. (See AN-247
(Literature Number SNOA595) for more information.)