LTC2644_15 Datasheet, PDF (1/20 Pages) Linear Technology – Dual 12-/10-/8-Bit PWM to VOUT DACs with 10ppm/C Reference

FEATURES
n _{No Latency PWM-to-Voltage Conversion}
n _{Voltage Output Updates and Settles within 8µs}
n _{100kHz to 30Hz PWM Input Frequency}
n _{±2.5LSB Max INL; ±1LSB Max DNL (LTC2644-12)}
n _{Guaranteed Monotonic}
n _{Pin-Selectable Internal or External Reference}
n _{2.7V to 5.5V Supply Range}
n _{1.71V to 5.5V Input Voltage Range}
n _{Low Power: 2.7mA at 3V, <1µA Power-Down}
n _{Guaranteed Operation from –40°C to 125°C}
n _{12-Lead MSOP Package}
APPLICATIONS
n _{Digital Calibration}
n _{Trimming and Adjustment}
n _{Level Setting}
n _{Process Control and Industrial Automation}
n _{Instrumentation}
n _Automotive
LTC2644
Dual 12-/10-/8-Bit PWM
to V_OUT DACs with
10ppm/°C Reference
DESCRIPTION
The LTC^®2644 is a family of dual 12-, 10-, and 8-bit PWM-
to-voltage output DACs with an integrated high accuracy,
low drift, 10ppm/°C reference in a 12-lead MSOP package. It
has rail-to-rail output buffers and is 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.
The LTC2644 has a full-scale output of 2.5V using the
10ppm/°C internal reference. It can operate with an external
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.
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
PWM INPUTS
1.7V TO 5.5V
2-Channel PWM to Voltage Output DAC
0.1µF
IN_A
V_OUTA
IN_B
V_OUTB
LTC2644
IOV_CC
REF
PD
V_CC
GND
IDLSEL
REFSEL
GND
BUFFERED
VOLTAGE
OUTPUTS
2.7V TO 5.5V
INPUT: 1V TO 5.5V
OUTPUT: 1.25V
0.1µF
0.1µF
2644 TA01a
PWM Input to DAC Output
IN_A
2V/DIV
V_OUTA
500mV/DIV
20µs/DIV
2644TA01b
2644f
For more information www.linear.com/LTC2644
1