AD5243BRMZ100-RL7 Analog Devices Inc, AD5243BRMZ100-RL7 Datasheet - Page 15

• Manufacturer Part Number: AD5243BRMZ100-RL7
• Description: IC,Digital Potentiometer,TSSOP,10PIN,PLASTIC
• Manufacturer: Analog Devices Inc

Specifications of AD5243BRMZ100-RL7

• Taps: 256
• Resistance (ohms): 100K
• Number Of Circuits: 2
• Temperature Coefficient: 35 ppm/°C Typical
• Memory Type: Volatile
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Resistance In Ohms: 100K
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AD5243EVAL - BOARD EVAL FOR AD5243
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

CONSTANT BIAS TO RETAIN RESISTANCE SETTING
For users who desire nonvolatility but cannot justify the addi-
tional cost of an EEMEM, the AD5243/AD5248 can be considered
low cost alternatives by maintaining a constant bias to retain the
wiper setting. The AD5243/AD5248 are designed specifically for
low power applications, allowing low power consumption even
in battery-operated systems. The graph in Figure 44 demonstrates
the power consumption from a 3.4 V, 450 mAhr Li-Ion cell phone
battery connected to the AD5243/AD5248. The measurement
over time shows that the device draws approximately 1.3 μA
and consumes negligible power. Over a course of 30 days, the
battery is depleted by less than 2%, the majority of which is due
to the intrinsic leakage current of the battery itself.
This demonstrates that constantly biasing the potentiometer
can be a practical approach. Most portable devices do not
require the removal of batteries for the purpose of charging.
Although the resistance setting of the AD5243/AD5248 is lost
when the battery needs replacement, such events occur rather
infrequently such that this inconvenience is justified by the
lower cost and smaller size offered by the AD5243/AD5248. If
110
108
106
104
102
100
98
96
94
92
90
0
Figure 44. Battery Operating Life Depletion
5
10
DAYS
15
20
T
A
=
25
25°C
30
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total power is lost, the user should be provided with a means to
adjust the setting accordingly.
EVALUATION BOARD
An evaluation board, along with all necessary software, is avail-
able to program the AD5243/AD5248 from any PC running
Windows 98/2000/XP. The graphical user interface, as shown in
Figure 45, is straightforward and easy to use. More detailed
information is available in the user manual, which is supplied
with the board.
The AD5243/AD5248 start at midscale upon power-up. To incre-
ment or decrement the resistance, simply move the scrollbars in
the left of the software window (see Figure 45). To write a specific
value, use the bit pattern in the upper part of the SDA Write Bit
Control (Hit Run) box and then click Run . The format of writing
data to the device is shown in Table 9. To read data from the
device, simply click Read . The format of the read bits is shown in
Table 11 and Table 12.
Figure 45. AD5243 Evaluation Board Software
AD5243/AD5248