SPT7921
12-BIT, 20 MSPS, TTL, A/D CONVERTER
FEATURES
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Monolithic
12-Bit 20 MSPS Converter
66 dB SNR @1 MHz Input
On-Chip Track/Hold
Bipolar
±2.0
V Analog Input
Low Power (1.1 W Typical)
5 pF Input Capacitance
TTL Outputs
APPLICATIONS
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Radar Receivers
Professional Video
Instrumentation
Medical Imaging
Electronic Warfare
Digital Communications
Digital Spectrum Analyzers
Electro-Optics
GENERAL DESCRIPTION
The SPT7921 A/D converter is the industry's first 12-bit
monolithic analog-to-digital converter capable of sample
rates greater than 20 MSPS. On board input buffer and
track/hold function assures excellent dynamic perfor-
mance without the need for external components. Drive
requirement problems are minimized with an input ca-
pacitance of only 5 pF.
Logic inputs and outputs are TTL. An overrange output signal
is provided to indicate overflow conditions. Output data
format is straight binary. Power dissipation is very low at only
1.1 watts with power supply voltages of +5.0 and -5.2 volts.
The SPT7921 also provides a wide input voltage range of
±2.0
volts.
The SPT7921 is available in 32-lead ceramic sidebrazed DIP
and 44-lead cerquad packages over the commercial tem-
perature range. Consult the factory for availability of die,
military temperature and /883 versions.
BLOCK DIAGRAM
V
IN
Input
Buffer
4-Bit Flash
Converter
4
Error
Correction,
Decoding
and
Output TTL
Drivers
Digital
Output
12
Analog Gain
Compression
Processor
Track-and-Hold
Amplifiers
Asynchronous
SAR
8
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
