LTC1448 Datasheet, PDF (1/12 Pages) Linear Technology – Dual 12-Bit Rail-to-Rail Micropower DAC

LTC1448
Dual 12-Bit Rail-to-Rail
Micropower DAC
FEATURES
s _{SO-8 Package}
s _{12-Bit Resolution}
s _{Buffered True Rail-to-Rail Voltage Output}
s _{External Reference Input Can Be Tied to VCC}
s _{Output Swings from 0V to VREF}
s _{3V and 5V Supply Operation}
s _{Schmitt Trigger on Clock Input Allows Direct}
Optocoupler Interface
s _{Power-On Reset Clears DACs to 0V}
s _{3-Wire Serial Interface}
s _{Maximum DNL Error: 0.5LSB}
s _{Low Cost}
U
APPLICATIONS
s _{Digital Calibration}
s _{Industrial Process Control}
s _{Automatic Test Equipment}
s _{Cellular Telephones}
DESCRIPTION
The LTC^®1448 is a dual rail-to-rail voltage output, 12-bit
digital-to-analog converter (DAC). It includes rail-to-rail
output buffer amplifiers and an easy-to-use 3-wire serial
interface. It is available in 8-pin SO and PDIP packages and
provides the smallest footprint of any dual 12-bit DAC.
The LTC1448 has an external reference input pin (REF)
and its outputs swing from 0V to REF. The REF input can
be tied to V_CC providing rail-to-rail operation from supplies
of 2.7V to 5.5V. (For devices with internal reference see the
LTC1446 data sheet.) The LTC1448 dissipates 2.5mW
from a 5V supply.
The low power supply current and the small SO-8 package
make the LTC1448 ideal for battery-powered applications.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
Functional Block Diagram: 12-Bit Rail-to-Rail Dual DAC
2.7V TO 5.5V
7
4
V_CC
REF
2 D_IN
µP
1 CLK
24-BIT
SHIFT
3 CS/LD _REG
AND
DAC
LATCH
12-BIT
DAC B
12-BIT
DAC A
+
V_{OUT B 8}
–
RAIL-TO-RAIL
VOLTAGE
OUTPUTS
+
V_{OUT A 5}
–
POWER-ON
RESET
GND
6
1448 TA01
Differential Nonlinearity
vs Input Code
0.5
0.4
0.3
0.2
0.1
0
– 0.1
– 0.2
– 0.3
– 0.4
– 0.5
0 512 1024 1536 2048 2560 3072 3584 4095
CODE
1448 TA02
1