max5402euat Maxim Integrated Products, Inc., max5402euat Datasheet - Page 7

• Manufacturer Part Number: max5402euat
• Description: Max5402 256-tap, ?pot Low-drift, Digital Potentiometer
• Manufacturer: Maxim Integrated Products, Inc.

The MAX5402 is intended for a variety of circuits where
accurate, fine-tuned adjustable resistance is required,
such as in adjustable voltage or adjustable gain circuit
configurations. The MAX5402 is used in either a poten-
tiometer divider or a variable resistor configuration.
Figure 4 shows the MAX5402 used with a MAX4250
low-noise op amp to precisely tune a current-to-voltage
converter. Pins H and W of the MAX5402 are connect-
ed to the node between R3 and R2, and pin L is con-
nected to ground.
The MAX5402 is used again with the MAX4250 to make
a digitally adjustable gain circuit as shown in Figure 5.
The normal feedback resistor is replaced with the
MAX5402 in a variable resistor configuration, so that
the gain of the circuit can be digitally controlled.
In Figure 6, the MAX5402 is shown with the MAX6160
to make an adjustable voltage reference. In this circuit,
the H pin of the MAX5402 is connected to the OUT pin
of the MAX6160, the L pin of the MAX5402 is connect-
ed to GND, and the W pin of the MAX5402 is connect-
ed to the ADJ pin of the MAX6160. The MAX5402
allows precise tuning of the voltage reference output. A
low 5ppm/°C ratiometric tempco allows a very stable
adjustable voltage overtemperature.
Figure 3. Serial Data Format
Data Word
B0 (D7)
(MSB)
First Bit In
Adjustable Current to Voltage Converter
Applications Information
B1 (D6)
Adjustable Voltage Reference
________________________________________________________________________________________
Adjustable Gain Amplifier
B2 (D5)
B3 (D4)
256-Tap, µPoT, Low-Drift,
B4 (D3)
Figure 4. I to V Converter
Figure 5. Noninverting Amplifier
Digital Potentiometer
V
B5 (D2)
S
V
R1
O
/ I
S
R3
= R
V
MAX4250
+5V
O
MAX4250
3
(1 + R
/ V
+5V
S
= 1 + R
2
B6 (D1)
/ R
1
) + R
W
L
2
/ R
2
1
R2
W
H
H
L
R1
MAX5402
MAX5402
V
O
B7 (D0)
(LSB)
Last Bit In
V
R2
O
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