LTC2641/LTC2642
APPLICATIONS INFORMATION
Bipolar Configuration
The amplifier circuit provides a gain of +2 from the V
OUT
pin, and gain of –1 from V . Tables 2a, 2b and 2c show
REF
Figure 3 shows a typical bipolar DAC application for the
the bipolar offset binary code tables for 16-bit, 14-bit and
12-bit operation.
LTC2642. The on-chip bipolar offset/gain resistors, R
FS
andR ,areconnectedtoanexternalamplifiertoproduce
ꢁIV
a bipolar output swing from –V to V at the R pin.
REF
REF
FS
V
REF
2.5V
5V/3V
OUT
LT1019CS8-2.5
GND
IN
5V
0.1μF
4.7μF
0.1μF
9
1
REF
V
DD
R
FB
8
5V
0.1μF
0.1μF
LTC2642-16
C1
10pF
–
INV
OUT
7
6
BIPOLAR V
OUT
1/2 LT1678
–2.5V TO 2.5V
V
+
2
3
4
5
16-BIT DAC
CS
SCLK
DIN
CLR
–5V
GND
10
26412 F02
Figure 3. 16-Bit Bipolar Output (LTC±64±-16) VOUT = –VREF to VREF
Table ±a. 16-Bit Bipolar Offset Binary
Code Table (LTC±64±-16)
Table ±b. 14-Bit Bipolar Offset Binary
Code Table (LTC±64±-14)
Table ±c. 1±-Bit Bipolar Offset Binary
Code Table (LTC±64±-1±)
DIGITAL INPUT
BINARY NUMBER
IN DAC LATCH
DIGITAL INPUT
BINARY NUMBER
IN DAC LATCH
DIGITAL INPUT
BINARY NUMBER
IN DAC LATCH
ANALOG OUTPUT
(V
ANALOG OUTPUT
(V
ANALOG OUTPUT
(V
)
)
)
OUT
OUT
OUT
MꢀS
LꢀS
MꢀS
LꢀS
MꢀS
LꢀS
1111 1111 1111 1111 V (32,767/32,768N
1111 1111 1111 11xx V (8,191/8,192N
1111 1111 1111 xxxx
1000 0000 0001 xxxx
V
V
(2,047/2,048N
(1/2,048N
REF
REF
REF
1000 0000 0000 0001 V (1/32,768N
1000 0000 0000 01xx V (1/8,192N
REF
REF
REF
1000 0000 0000 0000 0V
1000 0000 0000 00xx 0V
1000 0000 0000 xxxx 0V
0111 1111 1111 xxxx –V (1/2048N
0111 1111 1111 1111 –V (1/32,768N
0111 1111 1111 11xx –V (1/8,192N
REF
REF
REF
0000 0000 0000 0000 –V
0000 0000 0000 00xx –V
0000 0000 0000 xxxx –V
REF
REF
REF
26412f
13
Linear [ Linear ]
