SPT7725

8-BIT, 300 MSPS, FLASH A/D CONVERTER

TECHNICAL DATA

AUGUST 17, 2001

FEATURES

• Metastable errors reduced to 1 LSB

• Low input capacitance: 10 pF

• Wide input bandwidth: 210 MHz

• 300 MSPS conversion rate

• Typical power dissipation: 2.2 watts

APPLICATIONS

• Digital oscilloscopes

• Transient capture

• Radar, EW, ECM

• Direct RF down-conversion

• Medical electronics: ultrasound, CAT instrumentation

GENERAL DESCRIPTION

The SPT7725 is a monolithic flash A/D converter capable

of digitizing a two volt analog input signal into 8-bit digital

words at a 300 MSPS (typ) update rate.

For most applications, no external sample-and-hold is re-

quired for accurate conversion due to the device’s narrow

aperture time, wide bandwidth, and low input capacitance.

A single standard –5.2 volt power supply is required for

operation of the SPT7725, with nominal power dissipation

of 2.2 W. A proprietary decoding scheme reduces meta-

stable errors to the 1 LSB level.

The SPT7725 is available in 42-lead ceramic sidebrazed

DIP, surface-mount 44-lead cerquad, and 46-lead PGA

packages (all are pin-compatible with the SPT7710); the

cerquad and PGA packages allow access to additional

reference ladder taps, an overrange bit, and a data ready

output. The SPT7725 is available in the industrial tem-

perature range.

256

255

152

151

128

127

64

63

2

1

256 to

8-Bit

Encoder

ECL

Latches

and

Buffers

AGND

Analog Input

(Sense or Force)

VEE

CLK

CLK

Convert

2

Analog Input

(Force or Sense) AGND DGND

LINV MINV

DRINV

DREAD

Overrange

D7 MSB

D6

D5

D4

D3

D2

D1

D0 LSB

MSB D7

D6

D5

D4

D3

D2

D1

LSB D0

These functions are

available in the PGA and

cerquad packages only.

Clock

Buffer

Preamp

Comparator

BLOCK DIAGRAM