ANALOG DEVICES AD7398, AD7399 Service Manual

Quad, Serial-Input

DAC A

DAC A

REGISTER

INPUT
REG A

DAC B

REGISTER

INPUT
REG B

DAC C

REGISTER

INPUT
REG C

DAC D

REGISTER

INPUT
REG D

SERIAL

REGISTER

POWER

ON RESET

DAC D

DAC C

DAC B

12/10

CLK

V

OUT

A

V

OUT

B

V

OUT

C

V

OUT

D

SDI

V

SS

RS LDAC V

REF

C V

REF

D

GND

CS

V

DD

V

REF

B

V

REF

A

AD7398/AD7399

02179-001

0.5

–0.5

–0.4

–0.3

–0.2

–0.1

0

0.

1

0.2

0.3

0.4

0 4096358430722560204815361024512

DNL (LSB)

CODE (Decimal )

02179-002

VDD = +5V
V

SS

= –5V

V

REF

= +2.5V

T

A

= 25°C

FEATURES

AD7398—12-bit resolution
AD7399—10-bit resolution
Programmable power shutdown
Single (3 V to 5 V) or dual (±5 V) supply operation
3-wire, serial SPI®-compatible interface
Internal power-on reset
Double buffered registers for simultaneous

multichannel DAC update
Four separate rail-to-rail reference inputs
Thin profile, TSSOP-16 package available
Low tempco: 1.5 ppm/°C
Qualified for automotive applications

APPLICATIONS

Automotive output voltage span
Portable communications
Digitally controlled calibration
PC peripherals

GENERAL DESCRIPTION

12-Bit/10-Bit DACs

AD7398/AD7399

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

The AD7398/AD7399 family of quad, 12-bit/10-bit, voltage
output digital-to-analog converters (DACs) is designed to
operate from a single 3 V to 5 V supply or a dual ±5 V supply.
Built with the Analog Devices, Inc. robust CBCMOS process,
these monolithic DACs offer the user low cost with ease-of-use
in single or dual-supply systems.

Both parts are offered in the same pinout, enabling users to
select the appropriate resolution for their application without
redesigning the layout. For 8-bit resolution applications, see the
pin-compatible AD7304 product.

The AD7398/AD7399 are specified over the extended industrial

(−40°C to +125°C) temperature range. Parts are available in
The applied external reference, V
output voltage. Valid V

values include VSS < V

REF

, determines the full-scale

REF

< VDD that

REF

16-lead, wide body SOIC and ultracompact, thin, 1.1 mm

TSSOP packages.
result in a wide selection of full-scale outputs. For multiplying
applications, ac inputs can be as large as ±5 V

.

P

A doubled-buffered serial-data interface offers high speed, 3-wire,
SPI- and microcontroller-compatible inputs using serial data-in
(SDI), clock (CLK), and a chip-select (
sensitive, load-DAC strobe (

CS

). A common level-

LDAC

) input allows simultaneous
update of all DAC outputs from previously loaded input registers.
Additionally, an internal power-on reset forces the output voltage to
zero at system turn on. An external asynchronous reset (
forces all registers to the zero code state. A programmable power­shutdown feature reduces power dissipation on unused DACs.

Rev. C

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Trademarks and registered trademarks are the prop erty of their respective owner s.

RS

) also

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Figure 2. AD7398 DNL vs. Code (T

= 25°C)

A