2.7 V to 5.5 V, 12-Bit, 8 s
ADC in 8-Lead SOIC/PDIP
AD7896
FEATURES
FUNCTIONAL BLOCK DIAGRAM
100 kHz Throughput Rate
Fast 12-Bit Sampling ADC with 8 s Conversion Time
8-Lead PDIP and SOIC
V
DD
Single 2.7 V to 5.5 V Supply Operation
High Speed, Easy-to-Use Serial Interface
On-Chip Track-and-Hold Amplifier
Analog Input Range Is 0 V to Supply
High Input Impedance
AD7896
TRACK-AND-HOLD
V
IN
12-BIT
ADC
Low Power: 9 mW Typ
OUTPUT
REGISTER
CONVST
CLOCK
AGND
DGND
BUSY
SCLK SDATA
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The AD7896 is a fast, 12-bit ADC that operates from a single
2.7 V to 5.5 V supply and is housed in small 8-lead PDIP and
8-lead SOIC packages. The part contains an 8 µs successive
approximation ADC, an on-chip track-and-hold amplifier, an
on-chip clock, and a high speed serial interface.
1. Complete, 12-bit ADC in an 8-Lead Package.
The AD7896 contains an 8 µs ADC, a track-and-hold ampli-
fier, control logic, and a high speed serial interface, all in an
8-lead PDIP. The VDD input is used as the reference for the
part, so no external reference is needed. This offers consider-
able space saving over alternative solutions.
Output data from the AD7896 is provided via a high speed,
serial interface port. This 2-wire serial interface has a serial
clock input and a serial data output with the external serial
clock accessing the serial data from the part.
2. Low Power, Single-Supply Operation.
The AD7896 operates from a single 2.7 V to 5.5 V supply
and consumes only 9 mW typical. The automatic power-
down mode, where the part goes into power down once
conversion is complete and “wakes up” before the next con-
version cycle, makes the AD7896 ideal for battery-powered
or portable applications.
In addition to the traditional dc accuracy specifications, such as
linearity, full-scale, and offset errors, the AD7896 is also speci-
fied for dynamic performance parameters, including harmonic
distortion and signal-to-noise ratio.
3. High Speed Serial Interface.
The part accepts an analog input range of 0 V to VDD and operates
from a single 2.7 V to 5.5 V supply, consuming only 9 mW
typical. The VDD input is also used as the reference for the part
so that no external reference is required.
The part provides high speed serial data and serial clock lines
allowing for an easy, 2-wire serial interface arrangement.
The AD7896 features a high sampling rate mode and, for low
power applications, a proprietary automatic power-down mode
where the part automatically goes into power-down once conver-
sion is complete and “wakes up” before the next conversion cycle.
The part is available in a small, 8-lead, 0.3'' wide, plastic or
hermetic dual-in-line package (PDIP) and in an 8-lead, small
outline IC (SOIC).
Rev. D
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