
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
VREF
2.5V
VDD
LTC2641-16
UNIPOLAR VOUT
0V TO 2.5V
4.7F
0.1F
REF
1
6
8
VOUT
GND
26412 F02
0.1F
7
5
4
3
2
CS
SCLK
DIN
CLR
LT1019CS8-2.5
GND
OUT
5V
IN
The external amplifier provides a unity-gain buffer. The
LTC2642 can also be used in unipolar configuration by
tying RFB 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
(VOUT)
MSB
LSB
1111 1111 1111 11xx VREF (16,383/16,384)
1000 0000 0000 00xx VREF (8,192/16,384) = VREF/2
0000 0000 0000 01xx VREF (1/16,384)
0000 0000 0000 00xx 0V
Figure 2. 16-Bit Unipolar Output (LTC2641-16) Unipolar VOUT = 0V to VREF
Table 1a. 16-Bit Unipolar Binary Code Table
(LTC2641-16)
DIGITAL INPUT
BINARY NUMBER
IN DAC LATCH
ANALOG OUTPUT
(VOUT)
MSB
LSB
1111 1111 1111 1111 VREF (65,535/65,536)
1000 0000 0000 0000 VREF (32,768/65,536) = VREF/2
0000 0000 0000 0001 VREF (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
(VOUT)
MSB
LSB
1111 1111 1111 xxxx VREF (4,095/4,096)
1000 0000 0000 xxxx VREF (2,048/4,096) = VREF/2
0000 0000 0001 xxxx VREF (1/4,096)
0000 0000 0000 xxxx 0V