ADC0809

张衍波

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 for more information.)
Features
n Easy interface to all microprocessors
n Operates ratiometrically or with 5 VDC or analog span
adjusted voltage reference
n No zero or full-scale adjust required
n 8-channel multiplexer with address logic
n 0V to 5V input range with single 5V power supply
n Outputs meet TTL voltage level specifications
n ADC0808 equivalent to MM74C949
n ADC0809 equivalent to MM74C949-1
Key Specifications
n Resolution 8 Bits
n Total Unadjusted Error ±1?2 LSB and ±1 LSB
n Single Supply 5 VDC
n Low Power 15 mW
n Conversion Time 100 μs
Block Diagram