E
CAT5251
QuadDigitallyProgrammablePotentiometer(DPP™)with
256 Taps and SPI Interface
TM
FEATURES
■ Automatic recall of saved wiper settings at
■ Four linear-taper digitally programmable
power up
potentiometers
■ 2.5 to 6.0 volt operation
■ 256 resistor taps per potentiometer
■ End to end resistance 50kΩ or 100kΩ
■ Standby current less than 1µA
■ 1,000,000 nonvolatile WRITE cycles
■ 100 year nonvolatile memory data retention
■ 24-lead SOIC and 24-lead TSSOP
■ Industrial temperature range
■ Potentiometer control and memory access via
SPI interface
■ Low wiper resistance, typically 100Ω
■ Nonvolatile memory storage for up to four wiper
settings for each potentiometer
DESCRIPTION
registers is via a SPI serial bus. On power-up, the
contents of the first data register (DR0) for each of the
four potentiometers is automatically loaded into its
respective wiper control register.
The CAT5251 is four Digitally Programmable
Potentiometers (DPPs™) integrated with control logic
and 16 bytes of NVRAM memory. Each DPP consists of
a series of resistive elements connected between two
externallyaccessibleendpoints.Thetappointsbetween
eachresistiveelementareconnectedtothewiperoutputs
with CMOS switches. A separate 8-bit control register
(WCR)independentlycontrolsthewipertapswitchesfor
each DPP. Associated with each wiper control register
are four 8-bit non-volatile memory data registers (DR)
used for storing up to four wiper settings. Writing to the
wiper control register or any of the non-volatile data
The CAT5251 can be used as a potentiometer or as a
two terminal, variable resistor. It is intended for circuit
level or system level adjustments in a wide variety of
applications. Itisavailableinthe-40°Cto85°Cindustrial
operating temperature range and offered in a 24-lead
SOIC and TSSOP package.
FUNCTIONAL DIAGRAM
PIN CONFIGURATION
SOIC/TSSOP Package (J, W/U, Y)
R
R
H3
R
R
H2
H1
H0
24
23
22
21
20
19
18
17
16
15
14
13
HOLD
SO
A0
1
SCK
2
R
R
3
L2
W3
R
R
R
CS
SCK
SI
W0
W1
W2
W3
WIPER
CONTROL
REGISTERS
R
R
4
H2
SPI BUS
INTERFACE
H3
R
R
5
W2
L3
S
O
NC
NC
6
CAT
5251
V
7
GND
CC
R
R
8
W1
L0
WP
A0
A1
R
R
R
9
H1
H0
NONVOLATILE
DATA
REGISTERS
CONTROL
LOGIC
R
10
11
12
L1
W0
R
HOLD
A1
SI
CS
WP
R
R
L3
R
R
L2
L1
L0
© 2004 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
Document No. 2017, Rev. D
1