
9
LTC1454/LTC1454L
Figure 2
APPLICATIONS INFORMATION
WU
U
A Single Supply, 4-Quadrant Multiplying DAC
The LTC1454 can also be used for 4-quadrant multiplying
with an offset signal ground of 1.22V. This application is
shown in Figure 2. The inputs are connected to REFHI B or
REFHI A and have a 1.22V amplitude around a signal
ground of 1.22V. The outputs will swing from 0V to 2.44V,
as shown by the equation with the figure. Since the signal
ground is around 1.22V, REFLO is offset above ground by
using an LT1034CS8-1.2 as shown.
VOUT B
VCC
REFHI B
GND
REFLO
REFHI A
REFOUT
VCC
VOUT B
VOUT A
VINB
1.22V
± 1.22V
VINA
1.22V
± 1.22V
LT1034CS8-1.2
CLK
DIN
CS/LD
LTC1454
1454 F02
X1/X2 B
CLR
CLK
DIN
CS/LD
DOUT
X1/X2 A
VOUT A
5V
0.1
F
10k
VOA/B = VIN – VREFLO GAIN
– 1 +1 + VREFLO
= VIN – 1.22 2.0
– 1.0 + 1.22V
()
DIN
4096
DIN
4096