Datasheet

AD7376
Rev. D | Page 16 of 20
APPLICATIONS INFORMATION
HIGH VOLTAGE DAC
The AD7376 can be configured as a high voltage DAC as high
as 30 V. The circuit is shown in Figure 32. The output is













1
2
1V2.1
128
)(
R
RD
DV
O
(5)
Where D is the decimal code from 0 to 127.
AD7376
U2
AD8512
V+
V–
AD8512
V
OUT
V
DD
U1B
V
DD
R
BIAS
ADR512
D1
R2
R1
B
100kΩ
0
1119-032
U1A
Figure 32. High Voltage DAC
PROGRAMMABLE POWER SUPPLY
With a boost regulator such as ADP1611, AD7376 can be used
as the variable resistor at the regulator’s FB pin to provide the
programmable power supply (see Figure 33). The output is




















2
128
1V23.1
R
R
D
V
AB
O
(6)
Note that the AD7376’s V
DD
is derived from the output. Initially
L1 acts as a short, and V
DD
is one diode voltage drop below +5 V.
The output slowly establishes to the final value.
The AD7376 shutdown sleep-mode programming can be used
to program a desirable preset level at power-up.
AD7376
ADP161 1
1.23V
C
C
150pF
R
C
220kΩ
C
OUT
10µF
V
OUT
D1
L1
4.7µF
IN
GND
SS
FB
RT
SW
COMP
U2
C1
0.1µF
V
DD
R1
100kΩ
A
W
B
C
IN
10µF
5V
R2
8.5kΩ
C
SS
22nF
01119-033
U1
SD
Figure 33. Programmable Power Supply