LTC2641/LTC2642
16-/14-/12-Bit V
OUT
DACs in
3mm
×
3mm DFN
FEATURES
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DESCRIPTION
The LTC
®
2641/LTC2642 are families of 16-, 14- and 12-bit
unbuffered voltage output DACs. These DACs operate from
a single 2.7V to 5.5V supply and are guaranteed monotonic
over temperature. The LTC2641-16/LTC2642-16 provide
16-bit performance (±2LSB INL and ±1LSB DNL) over
temperature. Unbuffered DAC outputs result in low supply
current of 120μA and a low offset error of ±1LSB.
Both the LTC2641 and LTC2642 feature a reference input
range of 2V to V
DD
. V
OUT
swings from 0V to V
REF
. For
bipolar operation, the LTC2642 includes matched scaling
resistors for use with an external precision op amp (such
as the LT1678), generating a ±V
REF
output swing at R
FB
.
The LTC2641/LTC2642 use a simple SPI/MICROWIRE
compatible 3-wire serial interface which can be operated
at clock rates up to 50MHz and can interface directly
with optocouplers for applications requiring isolation. A
power-on reset circuit clears the LTC2641’s DAC output
to zero scale and the LTC2642’s DAC output to midscale
when power is initially applied. A logic low on the
⎯
C
⎯
L
⎯
R pin
asynchronously clears the DAC to zero scale (LTC2641)
or midscale (LTC2642). These DACs are all specified over
the commercial and industrial ranges.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Tiny 3mm
×
3mm 8-Pin DFN Package
Maximum 16-Bit INL Error: ±2LSB over Temperature
Low 120μA Supply Current
Guaranteed Monotonic over Temperature
Low 0.5nV•sec Glitch Impulse
2.7V to 5.5V Single Supply Operation
Fast 1μs Settling Time to 16 Bits
Unbuffered Voltage Output Directly Drives 60k Loads
50MHz SPI
TM
/QSPI
TM
/MICROWIRE
TM
Compatible
Serial Interface
Power-On Reset Clears DAC Output to Zero Scale
(LTC2641) or Midscale (LTC2642)
Schmitt-Trigger Inputs for Direct Optocoupler
Interface
Asynchronous
⎯
C
⎯
L
⎯
R Pin
8-Lead MSOP and 3mm
×
3mm DFN Packages
(LTC2641)
10-Lead MSOP and 3mm
×
3mm DFN Packages
(LTC2642)
APPLICATIONS
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High Resolution Offset and Gain Adjustment
Process Control and Industrial Automation
Automatic Test Equipment
Data Aquisition Systems
TYPICAL APPLICATION
Bipolar 16-Bit DAC
2.7V TO 5.5V
0.1μF
LTC2642
V
DD
REF
1μF
0.1μF
R
FB
V
REF
2V TO V
DD
LTC2642-16 Integral Nonlinearity
1.0
0.8
0.6
V
DD
= 5V
V
REF
= 2.5V
±2.5V
RANGE
1/2 LT1678
POWER-ON
RESET
CS
SCLK
DIN
CLR
16-BIT DAC
16-BIT DATA LATCH
CONTROL
LOGIC
16-BIT SHIFT REGISTER
GND
26412 TA01a
+
V
OUT
INL (LSB)
–
BIPOLAR V
OUT
–V
REF
TO V
REF
INV
5pF
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
0
16384
32768
CODE
49152
65535
LT1372 • G10
INL 25°C
INL 90°C
INL –45°C
26412f
1
LINER [ LINEAR TECHNOLOGY ]
