ADS7891IPFBT Datasheet, PDF (1/31 Pages) Texas Instruments – 14-BIT, 3-MSPS LOW POWER SAR ANALOG-TO-DIGITAL CONVERTER

ADS7891
SLAS410 − DECEMBER 2003
14ĆBIT, 3ĆMSPS
LOW POWER SAR ANALOGĆTOĆDIGITAL CONVERTER
FEATURES
D 3 MHz Sample Rate, 14-Bit Resolution
D Zero Latency
D Unipolar, Pseudo Differential Input, Range:
− 0 V to 2.5 V
D High Speed Parallel Interface
D 78 dB SNR and 88.5 dB THD at 3 MSPS
D Power Dissipation 85 mW at 3 MSPS
D Nap Mode (10 mW Power Dissipation)
D Power Down (10 mW)
D Internal Reference
D Internal Reference Buffer
D 8-/14-Bit Bus Transfer
D 48-Pin TQFP Package
APPLICATIONS
D Optical Networking (DWDM, MEMS Based
Switching)
D Spectrum Analyzers
D High Speed Data Acquisition Systems
D High Speed Close-Loop Systems
D Telecommunication
D Ultra-Sound Detection
DESCRIPTION
The ADS7891 is a 14-bit 3-MSPS A-to-D converter with 2.5-V internal reference. The device includes a
capacitor based SAR A/D converter with inherent sample and hold. The device offers a 14-bit parallel interface
with an additional byte mode that provides easy interface with 8-bit processors. The device has a
pseudo-differential input stage.
The −IN swing of ±200 mV is useful to compensate for ground voltage mismatch between the ADC and sensor
and also to cancel common-mode noise. With nap mode enabled, the device operates at lower power when
used at lower conversion rates. The device is available in a 48-pin TQFP package.
+IN
+
−IN
_
REFIN
REFOUT
SAR
CDAC
Comparator
Output
Latches
and
3-State
Drivers
BYTE
14/8-Bit Parallel
Data Output Bus
CLOCK
2.5 V
Internal
Reference
Conversion
and
Control Logic
PWD/RST
A_PWD
CONVST
BUSY
CS
RD
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments
semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date. Products
conform to specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all parameters.
Copyright  2003, Texas Instruments Incorporated