Document
ADS805
ADS805E
SBAS073B – JANUARY 1997 – REVISED NOVEMBER 2002
12-Bit, 20MHz Sampling ANALOG-TO-DIGITAL CONVERTER
FEATURES
q HIGH SFDR: 74dB at 9.8MHz fIN q HIGH SNR: 68dB q LOW POWER: 300mW q LOW DLE: 0.25LSB q FLEXIBLE INPUT RANGE q OVER-RANGE INDICATOR
DESCRIPTION
The ADS805 is a 20MHz, high dynamic range, 12-bit, pipelined Analog-to-Digital Converter ADC. This converter includes a high-bandwidth track-and-hold that gives excellent spurious performance up to and beyond the Nyquist rate. This highbandwidth, linear track-and-hold minimizes harmonics and has low jitter, leading to excellent Signal-to-Noise Ratio (SNR) performance. The ADS805 is also pin-compatible with the 10MHz ADS804 and the 5MHz ADS803.
The ADS805 provides an internal reference or an external reference can be used. The ADS805 can be programmed for a 2Vp-p input range which is the easiest to drive with a single op amp and provides the best spurious performance. Alter-
APPLICATIONS
q STUDIO CAMERAS q IF AND BASEBAND DIGITIZATION q COPIERS q TEST INSTRUMENTATION
natively, the 5Vp-p input range can be used for the lowest input-referred noise of 0.09LSBs rms giving superior imaging performance. There is also the capability to set the input range between 2Vp-p and 5Vp-p, either single-ended or differential. The ADS805 also provides an over-range flag that indicates when the input signal has exceeded the converter’s full-scale range. This flag can also be used to reduce the gain of the front end signal conditioning circuitry. The ADS805 employs digital error techniques to provide excellent differential linearity for demanding imaging applications. Its low distortion and high SNR give the extra margin needed for communications, medical imaging, video, and test instrumentation applications. The ADS805 is available in an SSOP-28 package.
+VS ADS805
CLK Timing Circuitry
VDRV
VIN
IN
T&H
IN
CM
12-Bit Pipelined ADC Core
Error Correction
Logic
D0
3-State Outputs
•••
D11
Reference Ladder and Driver
Reference and Mode Select
OVR
REFT
VREF
SEL REFB
OE
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.
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Copyright © 1997, Texas Instruments Incorporated
ABSOLUTE MAXIMUM RATINGS(1)
+VS ....................................................................................................... +6V Analog Input ............................................................. –0.3V to (+VS) + 0.3V Logic Input ............................................................... –0.3V to (+VS) + 0.3V Case Temperature ......................................................................... +100°C Junction Temperature .................................................................... +150°C Storage Temperature ..................................................................... +150°C
NOTE: (1) Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. Exposure to absolute maximum conditions for extended periods may affect device reliability.
ELECTROSTATIC DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
PACKAGE/ORDERING INFORMATION
PRODUCT
ADS805
"
PACKAGE-LEAD
SSOP-28
"
PACKAGE DESIGNATOR(1)
DB
"
SPECIFIED TEMPERATURE
RANGE
–40°C to +85°C
"
PACKAGE MARKING
ADS805E
"
NOTE: (1) For the most current specifications and package information, refer to our web site at www.ti.com.
ORDERING NUMBER(2)
ADS805E ADS805E/1K
TRANSPORT MEDIA, QUANTITY
Rails, 48 Tape and Reel, 1000
ELECTRICAL CHARACTERISTICS
At TA = full specified temperature range, VS = +5V, specified input range = 1.5V to 3.5V, and single-ended input and sampling rate = 20MHz, unless otherwise specified. ADS805E
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
RESOLUTION
SPECIFIED TEMPERATURE RANGE
CONVERSION CHARACTERISTICS Sample Rate Data Latency
ANALOG INPUT Standard Single-Ended Input Range Optional Single-Ended Input Range Standard Common-Mode Voltage Standard Optional Common-Mode Voltage Input Capacitance Analog Input Bandwidth
DYNAMIC CHARACTERISTICS Differential Linearity Error (Largest Code Error)
f = 500kHz No Missing Codes Spurious-Free Dynamic Range(1)
f.