MAX5401EKA-T Maxim Integrated Products, MAX5401EKA-T Datasheet - Page 7

• Manufacturer Part Number: MAX5401EKA-T
• Description: IC DIGITAL POT 256-TAP SOT23-8
• Manufacturer: Maxim Integrated Products

Specifications of MAX5401EKA-T

• Taps: 256
• Resistance (ohms): 100K
• Number Of Circuits: 1
• Temperature Coefficient: 50 ppm/°C Typical
• Memory Type: Volatile
• Interface: SPI, 3-Wire Serial
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-8
• Resistance In Ohms: 100K
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: MAX5401EKA-T; MAX5401EKA-TTR

Figure 4. Serial Data Format
The MAX5400/MAX5401 are intended for a variety of
circuits that require accurate, fine-tuning adjustable
resistance, such as adjustable voltage or adjustable
gain circuit configurations. The MAX5400/MAX5401 are
primarily used in either a potentiometer divider or a
variable resistor configuration.
Figure 5 shows the MAX5400/MAX5401 being used
with a MAX4250 low-noise op amp to fine tune a cur-
rent-to-voltage converter. Pins H and W of the
MAX5400/MAX5401 are connected to the node
between R3 and R2 and pin L is connected to ground.
The MAX5400/MAX5401 are used again with the
MAX4250 to make a digitally adjustable gain circuit as
shown in Figure 6. The normal feedback resistor is
replaced with the MAX5400/MAX5401 in a variable
Figure 5. I to V Converter
B0 (D7)
(MSB)
FIRST
BIT IN
Adjustable Current-to-Voltage Converter
Low-Drift Digital Potentiometers in SOT23
Applications Information
B1 (D6)
_______________________________________________________________________________________
V O / I S = R 3 (1 + R 2 / R 1 )+ R 2
Adjustable Gain Amplifier
R3
+5V
B2 (D5)
MAX4250
R1
B3 (D4)
V O
R2
DATA WORD
B4 (D3)
resistor configuration so that the gain of the circuit can
be digitally controlled.
In Figure 7, the MAX5400/MAX5401 are shown with the
MAX6160 to make an adjustable voltage reference. In
this circuit, the H pin of the MAX5400/MAX5401 is con-
nected to the OUT pin of the MAX6160, the L pin of the
MAX5400/MAX5401 is connected to GND, and the W
pin of the MAX5400/MAX5401 is connected to the ADJ
pin of the MAX6160. The MAX5400/MAX5401 allow pre-
cise tuning of the voltage reference output. A low
5ppm/°C ratiometric tempco allows a very stable
adjustable voltage over temperature.
Figure 6. Noninverting Amplifier
256-Tap SOT-PoT,
V
B5 (D2)
S
Adjustable Voltage Reference
R1
V
+5V
O
/ V
S
= 1 + R
B6 (D1)
MAX4250
2
/ R
1
R2
V
O
B7 (D0)
(LSB)
LAST
BIT IN
7