3 V to 5 V Single Supply, 200 kSPS
12-Bit Sampling ADCs
a
AD7853/AD7853L*
FUNCTIONAL BLOCK DIAGRAM
FEATURES
Specified for VDD of 3 V to 5.5 V
Read-Only Operation
AV
AGND AGND
DD
AD7853–200 kSPS; AD7853L–100 kSPS
System and Self-Calibration with Autocalibration on
Power-Up
DV
DD
AIN(+)
AIN(–)
AD7853/AD7853L
T/H
DGND
Low Power:
2.5V
AD7853: 12 mW (VDD = 3 V)
AD7853L: 4.5 mW (VDD = 3 V)
Automatic Power Down After Conversion (25 W)
Flexible Serial Interface:
REFERENCE
COMP
BUF
REF
/
IN
REF
OUT
8051/SPI™/QSPI™/P Compatible
24-Lead DIP, SOIC and SSOP Packages
C
REF1
AMODE
CHARGE
REDISTRIBUTION
DAC
APPLICATIONS
CLKIN
Battery-Powered Systems (Personal Digital Assistants,
Medical Instruments, Mobile Communications)
Pen Computers
Instrumentation and Control Systems
High Speed Modems
C
SAR + ADC
CONTROL
REF2
CONVST
BUSY
CALIBRATION
MEMORY
AND CONTROLLER
CAL
SLEEP
SERIAL INTERFACE / CONTROL REGISTER
GENERAL DESCRIPTION
SYNC
SM1 SM2
DIN DOUT SCLK POLARITY
The AD7853/AD7853L are high speed, low power, 12-bit
ADCs that operate from a single 3 V or 5 V power supply, the
AD7853 being optimized for speed and the AD7853L for low
power. The ADC powers up with a set of default conditions at
which time it can be operated as a read-only ADC. The ADC
contains self-calibration and system-calibration options to en-
sure accurate operation over time and temperature and have a
number of power-down options for low power applications.
The part powers up with a set of default conditions and can
operate as a read only ADC.
PRODUCT HIGHLIGHTS
1. Specified for 3 V and 5 V supplies.
2. Automatic calibration on power-up.
3. Flexible power management options including automatic
power-down after conversion.
4. Operates with reference voltages from 1.2 V to VDD
.
The AD7853 is capable of 200 kHz throughput rate while the
AD7853L is capable of 100 kHz throughput rate. The input
track-and-hold acquires a signal in 500 ns and features a pseudo-
differential sampling scheme. The AD7853/AD7853L voltage
range is 0 to VREF with both straight binary and twos comple-
ment output coding. Input signal range is to the supply, and the
part is capable of converting full power signals to 100 kHz.
5. Analog input ranges from 0 V to VDD
6. Self- and system calibration.
.
7. Versatile serial I/O port (SPI/QSPI/8051/µP).
8. Lower power version AD7853L.
CMOS construction ensures low power dissipation of typically
4.5 mW for normal operation and 1.15 mW in power-down
mode, with a throughput rate of 10 kSPS (VDD = 3 V). The part
is available in 24-lead, 0.3 inch wide dual-in-line package
(DIP), 24-lead small outline (SOIC) and 24-lead small shrink
outline (SSOP) packages.
*Patent pending.
SPI and QSPI are trademarks of Motorola, Incorporated.
REV. B
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use, nor for any infringements of patents or other rights of third parties
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© Analog Devices, Inc., 1998