CAT5112
32‐tap Digital
Potentiometer (POT)
with Buffered Wiper
Description
The CAT5112 is a single digital POT designed as an electronic
replacement for mechanical potentiometers. 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 CAT5112 contains a 32-tap series resistor array connected
between two terminals R
H
and R
L
. An up/down counter and decoder
that are controlled by three input pins, determines which tap is
connected to the wiper, R
WB
. The CAT5112 wiper is buffered by an op
amp that operates rail to rail. The wiper setting, stored in non-volatile
memory, is not lost when the device is powered down and is
automatically recalled when power is returned. The wiper can be
adjusted to test new system values without effecting the stored setting.
Wiper-control of the CAT5112 is accomplished with three input
control pins, CS, U/D, 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 digital POT can be used as a buffered voltage divider. For
applications where the potentiometer is used as a 2-terminal variable
resistor, please refer to the CAT5114. The buffered wiper of the
CAT5112 is not compatible with that application.
Features
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SOIC−8
V SUFFIX
CASE 751BD
MSOP−8
Z SUFFIX
CASE 846AD
PDIP−8
L SUFFIX
CASE 646AA
TSSOP−8
Y SUFFIX
CASE 948AL
PIN CONFIGURATIONS
INC
U/D
R
H
GND
1
V
CC
CS
R
L
R
WB
PDIP (L), SOIC (V), MSOP (Z)
CS
V
CC
INC
U/D
1
R
L
R
WB
GND
R
H
TSSOP (Y)
(Top Views)
32-position Linear Taper Potentiometer
Non-volatile EEPROM Wiper Storage; Buffered Wiper
Low Power CMOS Technology
Single Supply Operation: 2.5 V
−
6.0 V
Increment Up/Down Serial Interface
Resistance Values: 10 kW, 50 kW and 100 kW
Available in PDIP, SOIC, TSSOP and MSOP Packages
These Devices are Pb-Free, Halogen Free/BFR Free and are RoHS
Compliant
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
PIN FUNCTION
Pin Name
INC
U/D
R
H
GND
R
WB
R
L
CS
V
CC
Function
Increment Control
Up/Down Control
Potentiometer High Terminal
Ground
Buffered Wiper Terminal
Potentiometer Low Terminal
Chip Select
Supply Voltage
Applications
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 10 of this data sheet.
Semiconductor Components Industries, LLC, 2013
June, 2013
−
Rev. 16
1
Publication Order Number:
CAT5112/D
CAT5112
R
H
V
CC
R
H
U/D
INC
CS
Power On Recall
GND
Control
and
Memory
+
–
R
WB
+
–
R
L
R
L
R
WB
Figure 1. Functional Diagram
Figure 2. Electronic Potentiometer Implementation
Pin Description
INC:
Increment Control Input
The INC input (on the falling edge) 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
WB
:
Wiper Potentiometer Terminal (Buffered)
R
WB
is the buffered wiper terminal of the potentiometer. Its
position on the resistor array is controlled by the control
inputs, INC, U/D and CS.
R
L
:
Low End Potentiometer Terminal
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 CAT5112 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.
Device Operation
The CAT5112 operates like a digitally controlled
potentiometer with R
H
and R
L
equivalent to the high and low
terminals and R
WB
equivalent to the mechanical
potentiometer’s wiper. There are 32 available tap positions
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 wiper terminal is connected to one of the 32
taps and 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 CAT5112 is selected and will
respond to the U/D and INC inputs. HIGH to LOW
transitions on INC will increment or decrement the wiper
(depending on the state of the U/D input and five-bit
counter). The wiper, when at either fixed 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 CAT5112 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 CAT5112 may be deselected 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.
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CAT5112
Table 1. 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
R
H
C
H
Operation
Wiper toward R
H
Wiper toward R
L
Store Wiper Position
No Store, Return to Standby
Standby
R
WI
R
WB
C
W
C
L
R
L
Figure 3. Potentiometer Equivalent Circuit
Table 2. ABSOLUTE MAXIMUM RATINGS
Parameters
Supply Voltage
V
CC
to GND
Inputs
CS to GND
INC to GND
U/D to GND
R
H
to GND
R
L
to GND
R
WB
to GND
Operating Ambient Temperature
Commercial (‘C’ or Blank suffix)
Industrial (‘I’ suffix)
Junction Temperature
Storage Temperature
Lead Soldering (10 s max)
Ratings
−0.5
to +7
−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
0 to 70
−40
to +85
+150
−65
to +150
+300
Units
V
V
V
V
V
V
V
C
C
C
C
C
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
Table 3. RELIABILITY CHARACTERISTICS
Symbol
V
ZAP
(Note 1)
I
LTH
(Notes 1, 2)
T
DR
N
END
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
1. This parameter is tested initially and after a design or process change that affects the parameter.
2. Latch-up protection is provided for stresses up to 100 mA on address and data pins from
−1
V to V
CC
+ 1 V
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CAT5112
Table 4. DC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.5 V to +6 V unless otherwise specified)
Symbol
POWER SUPPLY
V
CC
I
CC1
I
CC2
I
SB1
(Note 4)
LOGIC INPUTS
I
IH
I
IL
V
IH1
V
IL1
V
IH2
V
IL2
R
POT
Input Leakage Current
Input Leakage Current
TTL High Level Input Voltage
TTL Low Level Input Voltage
CMOS High Level Input Voltage
CMOS Low Level Input Voltage
2.5 V
V
CC
6 V
V
IN
= V
CC
V
IN
= 0 V
4.5 V
V
CC
5.5 V
–
–
2
0
V
CC
x 0.7
−0.3
–
–
–
–
–
–
10
−10
V
CC
0.8
V
CC
+ 0.3
V
CC
x 0.2
mA
mA
V
V
V
V
Operating Voltage Range
Supply Current (Increment)
V
CC
= 6 V, f = 1 MHz, I
W
= 0
V
CC
= 6 V, f = 250 kHz, I
W
= 0
Supply Current (Write)
Programming, V
CC
= 6 V
V
CC
= 3 V
Supply Current (Standby)
CS = V
CC
−
0.3 V
U/D, INC = V
CC
−
0.3 V or GND
2.5
–
–
–
–
–
–
–
–
–
–
75
6
200
100
1000
500
150
V
mA
mA
mA
mA
mA
Parameter
Conditions
Min
Typ
Max
Units
POTENTIOMETER CHARACTERISTICS
Potentiometer Resistance
−10
Device
−50
Device
−00
Device
Pot. Resistance Tolerance
V
RH
V
RL
INL
DNL
R
OUT
I
OUT
TC
RPOT
TC
RATIO
C
RH
/C
RL
/C
RW
fc
V
WB(SWING)
3.
4.
5.
6.
Voltage on R
H
pin
Voltage on R
L
pin
Resolution
Integral Linearity Error
Differential Linearity Error
Buffer Output Resistance
Buffer Output Current
TC of Pot Resistance
Ratiometric TC
Potentiometer Capacitances
Frequency Response
Output Voltage Range
Passive Attenuator, 10 kW
I
OUT
100
mA,
V
CC
= 5 V
0.01 V
CC
I
W
2
mA
I
W
2
mA
0.05 V
CC
V
WB
0.95 V
CC
,
V
CC
= 5 V
0.05 V
CC
V
WB
0.95 V
CC
,
V
CC
= 5 V
300
20
8/8/25
1.7
0.99 V
CC
0
0
1
0.5
0.25
1
0.5
1
3
10
50
100
20
V
CC
V
CC
%
V
V
%
LSB
LSB
W
mA
ppm/C
ppm/C
pF
MHz
kW
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 100 mA on address and data pins from
−1
V to V
CC
+ 1 V
I
W
= source or sink
These parameters are periodically sampled and are not 100% tested.
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CAT5112
Table 5. AC TEST CONDITIONS
V
CC
Range
Input Pulse Levels
Input Rise and Fall Times
Input Reference Levels
2.5 V
V
CC
6 V
0.2 V
CC
to 0.7 V
CC
10 ns
0.5 V
CC
Table 6. AC OPERATING CHARACTERISTICS
(V
CC
= +2.5 V to +6.0 V, V
H
= V
CC
, V
L
= 0 V, unless otherwise specified)
Symbol
t
CI
t
DI
t
ID
t
IL
t
IH
t
IC
t
CPH
t
CPH
t
IW
t
CYC
t
R
, t
F
(Note 8)
t
PU
(Note 8)
t
WR
CS to INC Setup
U/D to INC Setup
U/D to INC Hold
INC LOW Period
INC HIGH Period
INC Inactive to CS Inactive
CS Deselect Time (NO STORE)
CS Deselect Time (STORE)
INC to V
OUT
Change
INC Cycle Time
INC Input Rise and Fall Time
Power-up to Wiper Stable
Store Cycle
Parameter
Min
100
50
100
250
250
1
100
10
−
1
−
–
–
Typ
(Note 7)
−
−
−
−
−
−
−
−
1
−
−
–
5
Max
−
−
−
−
−
−
−
−
5
−
500
1
10
Units
ns
ns
ns
ns
ns
ms
ns
ms
ms
ms
ms
ms
ms
7. Typical values are for T
A
= 25C and nominal supply voltage.
8. This parameter is periodically sampled and not 100% tested.
9. MI in the A.C. Timing diagram refers to the minimum incremental change in the W output due to a change in the wiper position.
CS
t
CYC
(store)
t
CPH
90%
t
DI
U/D
90%
10%
t
ID
t
F
t
R
t
CI
INC
t
IL
t
IH
t
IC
t
IW
R
WB
MI
(3)
Figure 4. A.C. Timing
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