LTC2634
1
2634fb
BLOCK DIAGRAM
FEATURES
APPLICATIONS
DESCRIPTION
Quad 12-/10-/8-Bit
Rail-to-Rail DACs with
10ppm/°C Reference
The LTC
®
2634 is a family of quad 12-, 10- and 8-bit volt-
age output DACs with an integrated, high accuracy, low
drift 10ppm/°C reference in 16-lead QFN and 10-lead
MSOP packages. It has rail-to-rail output buffers and is
guaranteed monotonic. The LTC2634-L has a full-scale
output of 2.5V, and operates from a single 2.7V to 5.5V
supply. The LTC2634-H has a full-scale output of 4.096V,
and operates from a 4.5V to 5.5V supply. Each DAC can
also operate with an external reference, which sets the
full-scale output to the external reference voltage.
These DACs communicate via an SPI/MICROWIRE compat-
ible 3-wire serial interface which operates at clock rates
up to 50MHz. Serial data output (SDO), a hardware clear
(CLR), and an asynchronous DAC update (LDAC) capability
are available in the QFN package. The LTC2634 incorporates
a power-on reset circuit. Options are available for reset
to zero-scale or reset to mid-scale in internal reference
mode, or reset to mid-scale in external reference mode
after power-up.
Integral Nonlinearity
(LTC2634-LZ12)
n
Integrated Precision Reference
2.5V Full-Scale 10ppm/°C (LTC2634-L)
4.096V Full-Scale 10ppm/°C (LTC2634-H)
n
Maximum INL Error: ±2.5 LSB (LTC2634-12)
n
Low Noise: 0.75mV
P-P
0.1Hz to 200KHz
n
Guaranteed Monotonic over –40°C to 125°C
Temperature Range
n
Selectable Internal or External Reference
n
2.7V to 5.5V Supply Range (LTC2634-L)
n
Ultralow Crosstalk Between DACs (2.4nV•s)
n
Low Power: 0.6mA at 3V
n
Power-On Reset to Zero-Scale/Mid-Scale
n
Double Buffered Data Latches
n
Tiny 16-Lead 3mm × 3mm QFN and 10-Lead
MSOP Packages
n
Mobile Communications
n
Process Control and Industrial Automation
n
Automatic Test Equipment
n
Portable Equipment
n
Automotive
REGISTER
REGISTER
REGISTER
REGISTER
DAC A
V
OUTA
(REFLO)
CS/LD
SCK
( ) QFN PACKAGE ONLY
(LDAC)
GND
V
OUTB
V
REF
DAC D
REGISTER
REGISTER
REGISTER
REGISTER
DAC B DAC C
V
REF
V
OUTD
REF
V
CC
V
REF
V
OUTC
SWITCH
INTERNAL
REFERENCE
32-BIT SHIFT REGISTER
DECODE
CONTROL
LOGIC
POWER-ON
RESET
SDI
2634 BD
(SDO)
(CLR)
CODE
0
INL (LSB)
0
1
4095
2634 TA01
–1
–2
1024
2048
3072
2
V
CC
= 3V
INTERNAL REF
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 5396245, 5859606, 6891433, 6937178, 7414561.
