ad7376 Analog Devices, Inc., ad7376 Datasheet - Page 16

• Manufacturer Part Number: ad7376
• Description: +30 V/?15 V Operation 128-position Digital Potentiometer
• Manufacturer: Analog Devices, Inc.

AD7376
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
Where D is the decimal code from 0 to 127.
ADR512
R
BIAS
V
O
V
(
DD
D
D1
)
=
R1
128
D
AD8512
⎡
⎢
⎣
1
V–
Figure 32. High Voltage DAC
2 .
V+
V
R2
DD
V
U1A
×
⎛ +
⎜
⎝
1
R
R
U2
2
1
AD7376
⎞
⎟
⎠
B
⎤
⎥
⎦
100kΩ
U1B
AD8512
V
Rev. B | Page 16 of 20
OUT
(5)
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
Note that the AD7376’s V
L1 acts as a short, and 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.
0.1µF
C1
V
O
U1
=
100kΩ
SD
8.5kΩ
V
AD7376
DD
. 1
R2
R1
23
A
B
V
Figure 33. Programmable Power Supply
W
×
⎡
⎢
⎢
⎢
⎢
⎣
1
+
⎛
⎜
⎝
DD
10µF
1.23V
5V
128
C
DD
22nF
D
is one diode voltage drop below +5 V.
IN
C
SS
R
is derived from the output. Initially
⎞
⎟
⎠
2
×
R
AB
U2
FB
RT
SS
⎤
⎥
⎥
⎥
⎥
⎦
ADP1611
GND
COMP
IN
SW
R
220kΩ
L1
4.7µF
C
150pF
C
C
D1
C
10µF
OUT
(6)
V
OUT