GENERAL DESCRIPTION

FEATURES

• 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

• Radar Receivers

• Professional Video

• Instrumentation

• Medical Imaging

• Electronic Warfare

• Digital Communications

• Digital Spectrum Analyzers

• Electro-Optics

SPT7921

12-BIT, 20 MSPS, TTL, A/D CONVERTER

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

12

Digital

Output

4

4-Bit Flash

Converter

Input

Buffer

Analog Gain

Compression

Processor

Track-and-Hold

Amplifiers

Asynchronous

SAR

Error

Correction,

Decoding

and

Output TTL

Drivers

8

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