LTC2640

1

2640fb

BLOCK DIAGRAM

FEATURES

APPLICATIONS

DESCRIPTION

Single 12-/10-/8-Bit SPI

10ppm/°C Reference

output DACs with an integrated, high-accuracy, low-drift

reference in an 8-lead TSOT-23 package. It has a rail-to-rail

output buffer that is guaranteed monotonic.

The LTC2640-L has a full-scale output of 2.5V, and operates

from a single 2.7V to 5.5V supply. The LTC2640-H has a

full-scale output of 4.096V, and operates from a 4.5V to

5.5V supply. A 10ppm/°C reference output is available at

the REF pin.

Each DAC can also operate in External Reference mode,

in which a voltage supplied to the REF pin sets the full-

scale output.

The LTC2640 DACs use a SPI/MICROWIRE™ compatible

3-wire serial interface which operates at clock rates up

to 50MHz.

The LTC2640 incorporates a power-on reset circuit. Op-

tions are available for Reset to Zero-Scale or Reset to

Mid-Scale after power-up.

Integral Nonlinearity (LTC2640A-LZ12)

2.5V Full-Scale 10ppm/°C (LTC2640-L)

4.096V Full-Scale 10ppm/°C (LTC2640-H)

L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property

of their respective owners. Protected by U.S. Patents including 5396245, 5859606, 6891433,

6937178 and 7414561.

(LTC2640-Z)

DAC

REGISTER

RESISTOR

DIVIDER

INTERNAL

REFERENCE

INPUT

REGISTER

24-BIT

SHIFT

REGISTER

DAC

SWITCH

CONTROL

DECODE LOGIC

CS/LD

REF

GND

CLR

DACREF

2640 TA01

SCK

SDI

CODE

0

0

0.5

4095

2640 TA01b

–0.5

–1.0

1024

2048

3072

1.0