AD5254BRUZ50 Analog Devices Inc, AD5254BRUZ50 Datasheet - Page 24
![IC POT DGTL QUAD 50K 20TSSOP](/photos/6/56/65613/ru-20_sml.jpg)
AD5254BRUZ50
Manufacturer Part Number
AD5254BRUZ50
Description
IC POT DGTL QUAD 50K 20TSSOP
Manufacturer
Analog Devices Inc
Datasheet
1.AD5254BRUZ100.pdf
(32 pages)
Specifications of AD5254BRUZ50
Memory Type
Non-Volatile
Temperature Coefficient
650 ppm/°C Typical
Taps
256
Resistance (ohms)
50K
Number Of Circuits
4
Interface
I²C, 2-Wire Serial
Voltage - Supply
2.7 V ~ 5.5 V, ±2.25 V ~ 2.75 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
20-TSSOP
Resistance In Ohms
50K
End To End Resistance
50kohm
Track Taper
Linear
Resistance Tolerance
± 30%
No. Of Steps
256
No. Of Pots
Quad
Potentiometer Ic Case
RoHS Compliant
Supply Voltage Range
± 2.25V To ± 2.75V
Control Interface
I2C, Serial
Rohs Compliant
Yes
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
For Use With
AD5254EVAL - BOARD EVAL FOR AD5254
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
AD5254BRUZ50
Manufacturer:
ADI/亚德诺
Quantity:
20 000
AD5253/AD5254
DIGITAL POTENTIOMETER OPERATION
The structure of the RDAC is designed to emulate the
performance of a mechanical potentiometer. The RDAC
contains a string of resistor segments with an array of analog
switches that act as the wiper connection to the resistor array.
The number of points is the resolution of the device. For
example, the AD5253/AD5254 emulate 64/256 connection
points with 64/256 equal resistance, R
provide better than 1.5%/0.4% resolution.
Figure 41 provides an equivalent diagram of the connections
between the three terminals that make up one channel of the
RDAC. Switches SW
switches SW(0) to SW(2
the setting decoded from the data bit). Because the switches are
nonideal, there is a 75 Ω wiper resistance, R
is a function of supply voltage and temperature: Lower supply
voltages and higher temperatures result in higher wiper
resistances. Consideration of wiper resistance dynamics is
important in applications in which accurate prediction of
output resistance is required.
R
DIGITAL
CIRCUITRY
OMIITTED FOR
CLARITY
REGISTER
S
DECODER
= R
WIPER
RDAC
AND
Figure 41. Equivalent RDAC Structure
AB
/2
A
N
and SW
N–1
R
R
R
) can be on at a time (determined by
S
S
S
B
are always on, but only one of
SW (2
SW (2
SW(1)
SW(0)
SW
SW
N
N
A
B
– 1)
– 2)
S
, allowing them to
W
A
B
W
X
X
X
. Wiper resistance
Rev. B | Page 24 of 32
PROGRAMMABLE RHEOSTAT OPERATION
If either the W-to-B or W-to-A terminal is used as a variable
resistor, the unused terminal can be opened or shorted with W;
such operation is called rheostat mode (see Figure 42). The
resistance tolerance can range ±20%.
The nominal resistance of the AD5253/AD5254 has 64/256
contact points accessed by the wiper terminal, plus the B
terminal contact. The 6-/8-bit data-word in the RDAC register
is decoded to select one of the 64/256 settings. The wiper’s first
connection starts at the B terminal for Data 0x00. This B termi-
nal connection has a wiper contact resistance, R
regardless of the nominal resistance. The second connection
(the AD5253 10 kΩ part) is the first tap point where R
(R
Each LSB data value increase moves the wiper up the resistor
ladder until the last tap point is reached at R
Figure 41 for a simplified diagram of the equivalent RDAC circuit.
The general equation that determines the digitally programmed
output resistance between W and B is
where:
D is the decimal equivalent of the data contained in the
RDAC latch.
R
AB
WB
is the nominal end-to-end resistance.
AD5253: RWB(D) = (D/64) × RAB + 75 Ω
AD5254: RWB(D) = (D/256) × RAB + 75 Ω
= R
A
B
AB
/64 + R
W
Figure 42. Rheostat Mode Configuration
W
= 156 Ω + 75 Ω) for Data 0x01, and so on.
A
B
W
A
B
WB
= 9893 Ω. See
W
, of 75 Ω,
W
WB
= 231 Ω
(1)
(2)