REV. A

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a

AD53041

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

World Wide Web Site: http://www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 1998

High Speed Active Load

with Inhibit Mode

FUNCTIONAL BLOCK DIAGRAM

FEATURES

50 mA Voltage Programmable Current Range

Three Selectable Gain Ranges

1.7 ns Propagation Delay

Inhibit Mode Function

High Speed Differential Inputs for Maximum Flexibility

Ultrasmall 20-Lead PSOP Package with Built-In Heatsink

APPLICATIONS

Automatic Test Equipment

Semiconductor Test Systems

Board Test Systems

PRODUCT DESCRIPTION

The AD53041 is a complete, high speed, current switching load

designed for use in linear, digital or mixed signal test systems.

Combining a high speed monolithic process with a unique sur-

face mount package, this product attains superb electrical per-

formance while preserving optimum packaging densities in an

ultrasmall 20-lead, PSOP package with a built-in heatsink.

Featuring current programmability of up to

±50 mA, the

AD53041 is designed to force the device under test to source

currents are determined by applying a corresponding voltage

The voltage-to-current conversion is performed within the

AD53041, thus allowing the current levels to be set by a stan-

dard voltage out digital-to-analog converter.

put voltage of the device under test slews above or below the

programmed threshold or commutation voltage. The commuta-

tion voltage is programmable from –2 V to +7 V, covering the

large spectrum of logic devices while able to support the large

current specifications (48 mA) typically associated with line

drivers. To test I/O devices, the active load can be switched into

a high impedance state (Inhibit Mode), electrically removing the

active load from the path through the Inhibit Mode feature. The

active load leakage current in Inhibit is typically 100 nA.

The Inhibit input circuitry is implemented using high speed

differential inputs with a common-mode voltage range of

–2 V to +3 V and a maximum differential voltage of 3 V. This

allows for direct interface to precision differential ECL timing or

the simplicity of switching active load from a single ended TTL

into Inhibit of less than 2.0 ns, the AD53041 can be electrically

removed from the signal path “on the fly.”

The AD53041 is available in a 20-lead, PSOP package with a

built-in-heatsink and is specified to operate over the ambient

commercial temperature range from –25

°C to +85°C.

AGND

OUT_SENSE

INH

INH

GAINA

GAINB

GND

AD53041

TO DUT

0.1 F

0.1 F

1

Ω

0.1 F

HSMS-2818

OR EQUIV.

NOT SHOWN: THE AGND PINS ARE THE HIGH QUALITY GROUND

REFERENCE FOR THE VOLTAGE-TO-CURRENT CONVERTERS.

THE GND PINS PROVIDE RETURN PATHS FOR INTERNAL CURRENTS.

ALL GROUND PINS SHOULD BE CONNECTED TO THE SYSTEM

ANALOG GROUND PLANE.

Figure 1. Typical Application Circuit

VOLTAGE-TO-CURRENT

CONVERTER

VOLTAGE-TO-CURRENT

CONVERTER

AD53041

BUFFER

INH

INH

OUT_SENSE

GAINB

GAINA

GAINA

GAINB

FULL-SCALE CURRENT

0

0

1

1

0

1

0

1

50mA

16mA

5mA

NOT VALID