Datasheet

LTC2641/LTC2642
13
26412fc
For more information www.linear.com/LTC2641
applicaTions inForMaTion
Unipolar Configuration
Figure 2 shows a typical unipolar DAC application for
the LTC2641. Tables 1a, 1b and 1c show the unipolar
binary code tables for 16-bit, 14-bit and 12-bit operation.
–
+
16-BIT DAC
1/2 LTC6078
5V/3V
5V/3V
V
REF
2.5V
V
DD
LTC2641-16
UNIPOLAR V
OUT
0V TO 2.5V
4.7µF
0.1µF
REF
1
6
8
V
OUT
GND
26412 F02
0.1µF
0.1µF
7
5
4
3
2
CS
SCLK
DIN
CLR
LT
®
1019CS8-2.5
GND
OUT 5VIN
The external amplifier provides a unity-gain buffer. The
LTC2642 can also be used in unipolar configuration by
tying R
FB
and INV to REF . This provides power-up and
clear to midscale.
Table 1b. 14-Bit Unipolar Binary Code Table
(LTC2641-14)
DIGITAL INPUT
BINARY NUMBER
IN DAC LATCH
ANALOG OUTPUT
(V
OUT
)
MSB LSB
1111 1111 1111 11xx V
REF
(16,383/16,384)
1000 0000 0000 00xx V
REF
(8,192/16,384) = V
REF
/2
0000 0000 0000 01xx V
REF
(1/16,384)
0000 0000 0000 00xx 0V
Figure 2. 16-Bit Unipolar Output (LTC2641-16) Unipolar V
OUT
= 0V to V
REF
Table 1a. 16-Bit Unipolar Binary Code Table
(LTC2641-16)
DIGITAL INPUT
BINARY NUMBER
IN DAC LATCH
ANALOG OUTPUT
(V
OUT
)
MSB LSB
1111 1111 1111 1111 V
REF
(65,535/65,536)
1000 0000 0000 0000 V
REF
(32,768/65,536) = V
REF
/2
0000 0000 0000 0001 V
REF
(1/65,536)
0000 0000 0000 0000 0V
Table 1c. 12-Bit Unipolar Binary Code Table
(LTC2641-12)
DIGITAL INPUT
BINARY NUMBER
IN DAC LATCH
ANALOG OUTPUT
(V
OUT
)
MSB LSB
1111 1111 1111 xxxx V
REF
(4,095/4,096)
1000 0000 0000 xxxx V
REF
(2,048/4,096) = V
REF
/2
0000 0000 0001 xxxx V
REF
(1/4,096)
0000 0000 0000 xxxx 0V