CAT5127, CAT5129
32-Tap Digitally Programmable Potentiometer (DPP™)
FEATURES
32-position linear taper potentiometer
Non-volatile EEPROM wiper storage
Low standby current
Single supply operation: 2.5V – 5.5V
Increment Up/Down serial interface
Resistance values: 10kΩ, 50kΩ and 100kΩ
CAT5127 in tiny 8-lead 2mm x 2.5mm TDFN and
MSOP packages
CAT5129 in the 6-lead TSOT23 package
DESCRIPTION
The CAT5127/CAT5129 are single digitally programmable
potentiometers (DPP™) designed as a electronic
replacement for mechanical potentiometers and trim
pots. Ideal for automated adjustments on high volume
production lines, they are also well suited for
applications where equipment requiring periodic
adjustment is either difficult to access or located in a
hazardous or remote environment.
The CAT5127 contains a 32-tap series resistor array
connected between two terminals R
H
and R
L
. The
CAT5129 contains a 32-tap series resistor array
connected between two terminals R
H
and GND. An
up/down counter and decoder that are controlled by
three input pins, determines which tap is connected to
the wiper. The wiper setting, stored in nonvolatile
memory, is not lost when the device is powered down
and is automatically reinstated when power is
returned. The wiper can be adjusted to test new
system values without effecting the stored setting.
Wiper-control
of
the
CAT5127/CAT5129
is
¯¯ , U/D,
¯
accomplished with three input control pins, CS
¯¯¯
¯¯¯
and INC. The INC input increments the wiper in the
direction which is determined by the logic state of the
¯
¯¯
U/D input. The CS input is used to select the device
and also store the wiper position prior to power down.
The devices are used as two-terminal variable
resistors. DPPs bring variability and programmability
to a wide variety of applications including control,
parameter adjustments, and signal processing.
APPLICATION
Automated product calibration
Remote control adjustments
Offset, gain and zero control
Tamper-proof calibrations
Contrast, brightness and volume controls
Motor controls and feedback systems
Programmable analog functions
For Ordering Information details, see page 12.
FUNCTIONAL DIAGRAM
CAT5127
V
CC
CAT5129
V
CC
R
P
(U/D)
(INC)
(CS)
POR
GND
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
R
H
(U/D)
(INC)
(CS)
POR
Control
and
Memory
R
H
Control
and
Memory
R
L
GND
1
Doc. No. MD-2127 Rev. C
CAT5127, CAT5129
PIN CONFIGURATION
MSOP/TDFN
CAT5127
¯¯¯
INC
¯
U/D
R
H
GND
1
2
3
4
8 V
CC
¯¯
7 CS
6 R
L
5 NC
PIN DESCRIPTIONS
Name Function
¯¯¯
INC
¯
U/D
R
H
Increment Control
Up/Down Control
Potentiometer High
Terminal
No Connect
Potentiometer Low
Terminal
Chip Select
Supply Voltage
CAT5127 CAT5129
MSOP/TDFN SOT23
1
2
3
4
5
6
7
8
4
3
5
2
-
-
1
6
GND Ground
TSOT23-6
CAT5129
¯¯
CS
GND
¯
U/D
1
2
3
6 V
CC
5 R
H
¯¯¯
4 INC
NC
R
L
¯¯
CS
V
CC
DEVICE DESCRIPTION
¯¯¯
INC:
Increment Control Input
¯¯¯
The INC input moves the wiper in the up or down
¯
direction determined by the condition of the U/D input.
¯
U/D:
Up/Down Control Input
¯
The U/D input controls the direction of the wiper
¯¯
movement. When in a high state and CS is low, any
¯¯¯
high-to-low transition on INC will cause the wiper to
move one increment toward the R
H
terminal. When in
¯¯
a low state and CS is low, any high-to-low transition
¯¯¯
on INC will cause the wiper to move one increment
towards the R
L
terminal.
R
H
:
High End Potentiometer Terminal
R
H
is the high end terminal of the potentiometer. It is
not required that this terminal be connected to a
potential greater than the R
L
terminal. Voltage applied
to the R
H
terminal cannot exceed the supply voltage,
V
CC
or go below ground, GND.
R
L
:
Low End Potentiometer Terminal (CAT5127 only)
R
L
is the low end terminal of the potentiometer. It is
not required that this terminal be connected to a
potential less than the R
H
terminal. Voltage applied to
the R
L
terminal cannot exceed the supply voltage, V
CC
or go below ground, GND. R
L
and R
H
are electrically
interchangeable.
¯¯
CS:
Chip Select
The chip select input is used to activate the control
input of the device and is active low. When in a high
¯¯¯
¯
state, activity on the INC and U/D inputs will not affect
or change the position of the wiper. CAT5127 has an
¯¯
internal pull-up resistor on the CS input pin.
V
CC
:
Supply Input for the device.
Doc. No. MD-2127 Rev. C
2
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT5127, CAT5129
DEVICE OPERATION
The CAT5127 operates like a digitally controlled
variable resistor with R
H
and R
L
equivalent to the high
and low terminals. There are 32 available tap posi-
tions including the resistor end points, R
H
and R
L
.
There are 31 resistor elements connected in series
between the R
H
and R
L
terminals.
The CAT5129 operates like a digitally controlled
variable resistor with R
H
equivalent to the high
terminal. There are 32 available tap positions
including the resistor end points, R
H
and GND. There
are 31 resistor elements connected in series between
the R
H
and GND terminals.
¯¯¯
¯
Operation is controlled by three inputs, INC, U/D and
¯¯
CS. These inputs control a five-bit up/down counter
whose output is decoded to select the wiper position.
The selected wiper position can be stored in
¯¯¯
¯¯
nonvolatile memory using the INC and CS inputs.
¯¯
With CS set LOW, the device is selected and will
¯
¯¯¯
respond to the U/D and INC inputs. HIGH to LOW
¯¯¯
transitions on INC wil increment or decrement the
¯
wiper (depending on the state of the U/D input and
five-bit counter). The wiper, when at either end
terminal, acts like its mechanical equivalent and does
not move beyond the last position. The value of the
¯¯
counter is stored in nonvolatile memory whenever CS
¯¯¯
transitions HIGH while the INC input is also HIGH.
When the device is powered-down, the last stored
wiper counter position is maintained in the nonvolatile
memory. When power is restored, the contents of the
memory are recalled and the counter is set to the
value stored.
¯¯¯
With INC set low, the device may be de-selected and
powered down without storing the current wiper
position in nonvolatile memory. This allows the system
to always power up to a preset value stored in
nonvolatile memory.
OPERATION MODES
¯¯¯
INC
High to Low
High to Low
High
Low
X
¯¯
CS
Low
Low
Low to High
Low to High
High
¯
U/D
High
Low
X
X
X
Operation
Wiper toward H
Wiper toward L/GND
Store Wiper Position
No Store, Return to Standby
Standby
R
H
C
H
C
L
R
L
/GND
Variable Resistor Equivalent Circuit
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
3
Doc. No. MD-2127 Rev. C
CAT5127, CAT5129
ABSOLUTE MAXIMUM RATINGS
(1)
Parameters
Supply Voltage
V
CC
to GND
Inputs
¯¯
CS to GND
¯¯¯
INC to GND
¯
U/D to GND
H to GND
L to GND
W to GND
Ratings
-0.5 to +7V
-0.5 to V
CC
+0.5
-0.5 to V
CC
+0.5
-0.5 to V
CC
+0.5
-0.5 to V
CC
+0.5
-0.5 to V
CC
+0.5
-0.5 to V
CC
+0.5
Units
V
V
V
V
V
V
V
Parameters
Operating Ambient Temperature
Commercial (‘C’ or Blank suffix)
Industrial (‘I’ suffix)
Junction Temperature
Storage Temperature
Lead Soldering (10 sec max)
Ratings
0 to 70
-40 to +85
+150
-65 to 150
+300
Units
ºC
ºC
ºC
ºC
ºC
RELIABILITY CHARACTERISTICS
Symbol
V
ZAP(2)
I
LTH
(2) (3)
Parameter
ESD Susceptibility
Latch-Up
Data Retention
Endurance
Test Method
MIL-STD-883, Test Method 3015
JEDEC Standard 17
MIL-STD-883, Test Method 1008
MIL-STD-883, Test Method 1003
Min
2000
100
100
1,000,000
Typ
Max
Units
V
mA
Years
Stores
T
DR
N
END
Notes:
(1) Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions outside of those listed in the operational sections of this
specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability.
(2)
(3)
(4)
This parameter is tested initially and after a design or process change that affects the parameter.
Latch-up protection is provided for stresses up to 100mA on address and data pins from -1V to V
CC
+ 1V
These parameters are periodically sampled and are not 100% tested.
Doc. No. MD-2127 Rev. C
4
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT5127, CAT5129
DC ELECTRICAL CHARACTERISTICS
V
CC
= +2.5V to +5.5V unless otherwise specified
Power Supply
Symbol
V
CC
Parameter
Operating Voltage Range
CAT5127
Supply Current (Increment)
CAT5129
Supply Current (Increment)
Supply Current (Write)
Supply Current (Standby)
V
CC
= 5.5V, f = 1MHz, I
W
= 0
V
CC
= 3.3V, f = 1MHz, I
W
= 0
V
CC
= 5.5V, f = 1MHz, I
W
= 0
V
CC
= 3.3V, f = 1MHz, I
W
= 0
Programming, V
CC
= 5.5V
Programming, V
CC
= 3.3V
¯¯
CS = V
CC
- 0.3V
¯ ¯¯¯
U/D, INC = V
CC
or GND
Conditions
¯ ¯¯¯
U/D, INC = V
CC
¯¯
CS = V
CC
-0.3V
V
IN
= V
CC
¯ ¯¯¯
U/D, INC = 0
¯¯
CS = 0
V
IN
= 0V
2.5V
≤
V
CC
≤
5.5V
V
CC
x 0.7
-0.3
2
3.6V
≤
V
CC
≤
5.5V
0
0.8
V
Min
300
150
0.35
Conditions
Min
2.5
Typ
Max
5.5
260
150
160
50
600
400
1
Units
V
µA
µA
µA
µA
µA
µA
µA
I
CC1
I
CC2
I
SB1(1)
Logic Inputs
Symbol
I
IH
Parameter
CAT5127 Input Leakage Current
CAT5129 Input Leakage Current
I
IL
V
IH2
V
IL2
V
IH1
V
IL1
CAT5127 Input Leakage Current
CAT5129 Input Leakage Current
CMOS High Level Input Voltage
CMOS Low Level Input Voltage
CAT5129 TTL High Level Input
Voltage
CAT5129 TTL Low Level Input
Voltage
Typ
Max
1
1
1
-1
-120
-1
V
CC
+ 0.3
V
CC
x 0.2
V
CC
Units
µA
µA
µA
µA
µA
µA
V
V
V
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
5
Doc. No. MD-2127 Rev. C
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