LTC2644
Dual 12-/10-/8-Bit PWM
to V DACs with
OUT
10ppm/°C Reference
FeaTures
DescripTion
The LTC®2644 is a family of dual 12-, 10-, and 8-bit PWM-
to-voltage output DACs with an integrated high accuracy,
lowdrift,10ppm/°Creferenceina12-leadMSOPpackage.It
hasrail-to-railoutputbuffersandisguaranteedmonotonic.
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No Latency PWM-to-Voltage Conversion
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Voltage Output Updates and Settles within 8µs
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100kHz to 30Hz PWM Input Frequency
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2.5LSB Max INL; 1LSB Max DNL (LTC2644-12)
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Guaranteed Monotonic
The LTC2644 measures the period and pulse width of the
PWM input signals and updates the voltage output DACs
after each corresponding PWM input rising edge. The
DAC outputs update and settle to 12-bit accuracy within
8µs typically and are capable of sourcing and sinking up
to 5mA (3V) or 10mA (5V), eliminating voltage ripple and
replacing slow analog filters and buffer amplifiers.
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Pin-Selectable Internal or External Reference
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2.7V to 5.5V Supply Range
1.71V to 5.5V Input Voltage Range
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Low Power: 2.7mA at 3V, <1µA Power-Down
Guaranteed Operation from –40°C to 125°C
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12-Lead MSOP Package
The LTC2644 has a full-scale output of 2.5V using the
10ppm/°Cinternalreference.Itcanoperatewithanexternal
reference, which sets the full-scale output equal to the ex-
ternal reference voltage. Each DAC enters a pin-selectable
idle state when the PWM input is held unchanged for
more than 60ms. The part operates from a single 2.7V
to 5.5V supply and supports PWM input voltages from
1.71V to 5.5V.
applicaTions
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Digital Calibration
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Trimming and Adjustment
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Level Setting
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Process Control and Industrial Automation
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Instrumentation
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Automotive
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.
Typical applicaTion
2-Channel PWM to Voltage Output DAC
PWM Input to DAC Output
PWM INPUTS
IN
A
BUFFERED
VOLTAGE
OUTPUTS
IN
IN
V
A
OUTA
2V/DIV
V
B
OUTB
LTC2644
INPUT: 1V TO 5.5V
OUTPUT: 1.25V
1.7V TO 5.5V
IOV
REF
CC
PD
0.1µF
V
2.7V TO 5.5V
0.1µF
CC
V
OUTA
500mV/DIV
GND
IDLSEL
REFSEL
GND
0.1µF
2644 TA01a
2644TA01b
20µs/DIV
2644fa
1
For more information www.linear.com/LTC2644