LTC2634
1
2634fc
Block Diagram
Features
app
lications
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 and
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, 7414561.
