a
FEATURES
Fast 12-Bit ADC with 1.47 s Conversion Time
600 kSPS Throughput Rate (AD7892-3)
500 kSPS Throughput Rate (AD7892-1, AD7892-2)
Single Supply Operation
On-Chip Track/Hold Amplifier
Selection of Input Ranges:
؎10 V or ؎5 V for AD7892-1
0 V to +2.5 V for AD7892-2
؎2.5 V for AD7892-3
High Speed Serial and Parallel Interface
Low Power, 60 mW typ
Overvoltage Protection on Analog Inputs (AD7892-1
and AD7892-3)
LC2MOS Single Supply,
12-Bit 600 kSPS ADC
AD7892
FUNCTIONAL BLOCK DIAGRAM
REF OUT/REF IN
VDD
2k⍀
+2.5V
AD7892
MODE
REFERENCE
DB0
DB2
DB3/RFS
12-BIT
DB4/SCLK
DB5/SDATA
DB10/LOW
DB11/LOW
ADC
VIN1
SIGNAL
VIN2
SCALING
TRACK/HOLD
CLOCK
CONTROL LOGIC
CS
GENERAL DESCRIPTION
The AD7892 is a high speed, low power, 12-bit A/D converter
that operates from a single +5 V supply. The part contains a
1.47 µs successive approximation ADC, an on-chip track/hold
amplifier, an internal +2.5 V reference and on-chip versatile
interface structures that allow both serial and parallel connection to a microprocessor. The part accepts an analog input range
of ± 10 V or ± 5 V (AD7892-1), 0 V to +2.5 V (AD7892-2) and
± 2.5 V (AD7892-3). Overvoltage protection on the analog inputs
for the AD7892-1 and AD7892-3 allows the input voltage to go
to ± 17 V or ± 7 V respectively without damaging the ports.
The AD7892 offers a choice of two data output formats: a
single, parallel, 12-bit word or serial data. Fast bus access times
and standard control inputs ensure easy parallel interface to
microprocessors and digital signal processors. A high speed
serial interface allows direct connection to the serial ports of
microcontrollers and digital signal processors.
In addition to the traditional dc accuracy specifications such as
linearity, full-scale and offset errors, the part is also specified for
dynamic performance parameters including harmonic distortion
and signal-to-noise ratio.
RD
EOC CONVST
AGND DGND
STANDBY
The AD7892 is fabricated in Analog Devices’ Linear Compatible CMOS (LC2MOS) process, a mixed technology process
that combines precision bipolar circuits with low power CMOS
logic. It is available in a 24-lead, 0.3" wide, plastic or hermetic
DIP or in a 24-lead SOIC.
PRODUCT HIGHLIGHTS
1. The AD7892-3 features a conversion time of 1.47 µs and a
track/hold acquisition time of 200 ns. This allows a throughput rate for the part up to 600 kSPS. The AD7892-1 and
AD7892-2 operate with throughput rates of 500 kSPS.
2. The AD7892 operates from a single +5 V supply and consumes 60 mW typ making it ideal for low power and portable
applications.
3. The part offers a high speed, flexible interface arrangement
with parallel and serial interfaces for easy connection to
microprocessors, microcontrollers and digital signal
processors.
REV. C
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2000
