AD5258BRMZ100 Analog Devices Inc, AD5258BRMZ100 Datasheet - Page 20

• Manufacturer Part Number: AD5258BRMZ100
• Description: IC POT DGTL I2C 100K 64P 10MSOP
• Manufacturer: Analog Devices Inc

Specifications of AD5258BRMZ100

• Memory Type: Non-Volatile
• Temperature Coefficient: 200 ppm/°C Typical
• Taps: 64
• Resistance (ohms): 100K
• Number Of Circuits: 1
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Resistance In Ohms: 100K
• End To End Resistance: 100kohm
• Resistance Tolerance: ± 30%
• No. Of Steps: 64
• Supply Voltage Range: 2.7V To 5.5V
• No. Of Pots: Single
• Control Interface: I2C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AD5258EVAL - BOARD EVAL FOR AD5258 DGTL POT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

AD5258
DISPLAY APPLICATIONS
CIRCUITRY
A special feature of the AD5258 is its unique separation of the
V
provide greater flexibility in applications that do not always
provide needed supply voltages.
In particular, LCD panels often require a V
range of 3 V to 5 V. The circuit in Figure 45 is the rare exception
in which a 5 V supply is available to power the digital
potentiometer.
1µF
In the more common case shown in Figure 46, only analog 14.4 V
and digital logic 3.3 V supplies are available. By placing discrete
resistors above and below the digital pot, V
off the resistor string itself. Based on the chosen resistor values,
the voltage at V
be safely operated all the way up to 4.8 V. The current draw of
C1
LOGIC
VCC (~3.3V)
MCU
and V
10kΩ
R6
DD
10kΩ
R5
supply pins. The reason for doing this is to
DD
Figure 45. V
in this case equals 4.8 V, allowing the wiper to
5V
AD5258
V
V
SCL
SDA
GND
DD
LOGIC
COM
14.4V
A
B
Adjustment Application
R1
70kΩ
R2
10kΩ
R3
25kΩ
W
–
+
AD8565
COM
U1
DD
can now be tapped
voltage in the
3.5V < V
COM
< 4.5V
Rev. 0 | Page 20 of 24
V
order of microamps. V
supply because V
when writing to the EEPROM. It would be impractical to try
and source 35 mA through the 70 kΩ resistor, therefore, V
is not connected to the same node as V
For this reason, V
supply pins that can either be tied together or treated inde-
pendently; V
and V
flexibility.
1µF
For a more detailed look at this application, refer to the article,
“Simple VCOM Adjustment uses any Logic Supply Voltage” in
the September 30, 2004, issue of EDN magazine.
C1
DD
VCC (~3.3V)
Figure 46. Circuitry When a Separate Supply is Not Available for V
will not affect that node’s bias because it is only on the
MCU
DD
10kΩ
biasing up the A, B, and W terminals for added
R6
SUPPLIES POWER
TO BOTH THE
MICRO AND THE
LOGIC SUPPLY OF
THE DIGITAL POT
LOGIC
10kΩ
R5
LOGIC
LOGIC
supplying the logic/EEPROM with power,
will draw the 35 mA which is needed
AD5258
LOGIC
and V
V
V
SCL
SDA
GND
DD
LOGIC
is tied to the MCU’s 3.3 V digital
14.4V
DD
A
B
R1
70kΩ
R2
10kΩ
R3
25kΩ
are provided as two separate
W
DD
–
+
AD8565
.
U1
3.5V < V
COM
LOGIC
DD
< 4.5V