1
2004 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
Doc. No. 2117, Rev. E
APPLICATIONS
s
Automated product calibration
s
Remote control adjustments
s
Offset, gain and zero control
s
Tamper-proof calibrations
s
Contrast, brightness and volume controls
s
Motor controls and feedback systems
s
Programmable analog functions
CAT5115
32-Tap Digitally Programmable Potentiometer (DPPTM)
FEATURES
s
32-position, linear-taper potentiometer
s
Low power CMOS technology
s
Single supply operation: 2.5V-5.5V
s
Increment up/down serial interface
s
Resistance values: 10k
, 50k
and 100k
s
Available in PDIP, SOIC, TSSOP and MSOP packages
determined by the logic state of the U/
D
input. The
CS
input is used to select the device.
The digitally programmable potentiometer can be
used as a three-terminal resistive divider or as a
two-terminal variable resistor. DPPs bring variability and
programmability to a wide variety of applications
including control, parameter adjustments, and
signal processing.
For a pin-compatible device that recalls a stored tap
position on power-up refer to the CAT5114 data sheet.
FUNCTIONAL DIAGRAM
DESCRIPTION
The CAT5115 is a single digitally programmable
potentiometer (DPPTM) 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 CAT5115 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
W
. The wiper is always set to the mid point, tap
15 at power up. The tap position is not stored in memory.
Wiper-control of the CAT5115 is accomplished with
three input control pins,
CS
, U/
D
, and
INC
. The
INC
input increments the wiper in the direction which is
GENERAL
DETAILED
ELECTRONIC POTENTIOMETER
IMPLEMENTATION
R
H
V
W
L
R
R
H
V
V
W
L
/
/
/
(
INC
)
(U/
D
)
(
CS
)
Control
and
Memory
INCREMENT
UP/DOWN
DEVICE SELECT
Vcc (Supply Voltage)
GENERAL
R
H
V
W
L
R
R
H
V
V
W
L
/
/
/
POR
GND
HA
LOGEN FREE
TM
LEAD FREE
ONE
OF
THIRTY TWO
DECODER
31
30
29
28
2
1
0
TRANSFER
GATES
RESISTOR
ARRAY
R
H
L
R
H
V
V
L
/
/
V
W
R
W
/
CONTROL
CIRCUITRY
U
/D
INC
CS
Vcc
V
SS
5-BIT
UP/DOWN
COUNTER
Preliminary Information
CAT5115
2
Doc. No. 2117, Rev. E
CS
CS
CS
CS
CS
: Chip Select
The chip select input is used to activate the control input
of the CAT5115 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 CAT5115 operates like a digitally controlled
potentiometer with R
H
and R
L
equivalent to the high
and low terminals and R
W
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.
With
CS
set LOW the CAT5115 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 fixed terminal,
acts like its mechanical equivalent and does not move
beyond the last position. When the CAT5115 is powered-
down, the wiper position is reset. When power is restored,
the counter is set to the mid point, tap 15.
PIN DESCRIPTIONS
INC
INC
INC
INC
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
D
D
D
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
W
: Wiper Potentiometer Terminal
R
W
is the wiper terminal of the potentiometer. Its position
on the resistor array is controlled by the control inputs,
INC
,
U/
D
and
CS
. Voltage applied to the R
W
terminal cannot
exceed the supply voltage, V
CC
or go below ground, GND.
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.
PIN FUNCTIONS
Pin Name
Function
INC
Increment Control
U/
D
Up/Down Control
R
H
Potentiometer High Terminal
GND
Ground
R
W
Potentiometer Wiper Terminal
R
L
Potentiometer Low Terminal
CS
Chip Select
V
CC
Supply Voltage
PIN CONFIGURATION
DIP Package (P, L)
TSSOP Package (U, Y)
MSOP Package (R, Z)
CS
INC
V
CC
U
/D
GND
RH
RL
RW
1
2
3
4
8
7
6
5
INC
V
CC
CS
U
/D
GND
R
W
R
H
R
L
1
2
3
4
8
7
6
5
V
CC
R
R
GND
R
INC
U/
D
CS
W
L
H
1
2
3
4
8
7
6
5
SOIC Package (S, V)
CS
INC
V
CC
U
/D
GND
RH
RL
RW
1
2
3
4
8
7
6
5
CAT5115
3
Doc. No. 2117, Rev. E
RELIABILITY CHARACTERISTICS
Symbol
Parameter
Test Method
Min
Typ
Max
Units
V
ZAP
(1)
ESD Susceptibility
MIL-STD-883, Test Method 3015
2000
Volts
I
LTH
(1)(2)
Latch-Up
JEDEC Standard 17
100
mA
T
DR
Data Retention
MIL-STD-883, Test Method 1008
100
Years
N
END
Endurance
MIL-STD-883, Test Method 1003
1,000,000
Stores
Power Supply
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
CC
Operating Voltage Range
2.5
--
5.5
V
I
CC1
Supply Current (Increment)
V
CC
= 5.5V, f = 1MHz, I
W
=0
--
--
100
A
V
CC
= 5.5V, f = 250kHz, I
W
=0
--
--
50
I
CC2
Supply Current (Write)
Programming, V
CC
= 5.5V
--
--
1
mA
V
CC
= 3V
--
--
500
A
ISB
1
(2)
Supply Current (Standby)
CS=V
CC
-0.3V
--
--
1
A
U/D, INC=V
CC
-0.3V or GND
OPERATION MODES
ABSOLUTE MAXIMUM RATINGS
Supply Voltage
V
CC
to GND ...................................... 0.5V to +7V
Inputs
CS
to GND ............................. 0.5V to V
CC
+0.5V
INC
to GND ............................ 0.5V to V
CC
+0.5V
U/
D
to GND ............................ 0.5V to V
CC
+0.5V
H to GND ................................ 0.5V to V
CC
+0.5V
L to GND ................................ 0.5V to V
CC
+0.5V
W to GND ............................... 0.5V to V
CC
+0.5V
Operating Ambient Temperature
Industrial (`I' suffix) ...................... 40
C to +85
C
Junction Temperature ..................................... +150
C
Storage Temperature ....................... 65
C to +150
C
Lead Soldering (10 sec max) .......................... +300
C
* Stresses above those listed under Absolute Maximum Ratings may
cause permanent damage to the device. Absolute Maximum Ratings
are limited values applied individually while other parameters are
within specified operating conditions, and functional operation at any
of these conditions is NOT implied. Device performance and reliability
may be impaired by exposure to absolute rating conditions for extended
periods of time.
NOTES:
(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 100mA on address and data pins from 1V to V
CC
+ 1V
(3) I
W
=source or sink
(4) These parameters are periodically sampled and are not 100% tested.
R
L
C
L
C
H
R
H
C
W
R
W
R
wi
Potentiometer
Equivalent Circuit
DC Electrical Characteristics: V
CC
= +2.5V to +5.5V unless otherwise specified
Symbol
Parameter
Conditions
Min
Typ
Max
Units
I
IH
Input Leakage Current
V
IN
= V
CC
--
--
10
A
I
IL
Input Leakage Current
V
IN
= 0V
--
--
10
A
V
IH1
TTL High Level Input Voltage
4.5V
V
CC
5.5V
2
--
V
CC
V
V
IL1
TTL Low Level Input Voltage
0
--
0.8
V
V
IH2
CMOS High Level Input Voltage
2.5V
V
CC
5.5V
V
CC
x 0.7
--
V
CC
+ 0.3
V
V
IL2
CMOS Low Level Input Voltage
-0.3
--
V
CC
x 0.2
V
Logic Inputs
INC
CS
U/D
Operation
High to Low
Low
High
Wiper toward H
High to Low
Low
Low
Wiper toward L
X
High
X
Standby
CAT5115
4
Doc. No. 2117, Rev. E
Symbol
Parameter
Conditions
Min
Typ
Max
Units
R
POT
Potentiometer Resistance
-10 Device
10
-50 Device
50
k
-00 Device
100
Pot Resistance Tolerance
20
%
V
RH
Voltage on R
H
pin
0
V
CC
V
V
RL
Voltage on R
L
pin
0
V
CC
V
Resolution
3.2
%
INL
Integral Linearity Error
I
W
2
A
0.5
1
LSB
DNL
Differential Linearity Error
I
W
2
A
0.25
0.5
LSB
R
Wi
Wiper Resistance
V
CC
= 5V, I
W
= 1mA
400
V
CC
= 2.5V, I
W
= 1mA
1
k
I
W
Wiper Current
1
mA
TC
RPOT
TC of Pot Resistance
300
ppm/
o
C
TC
RATIO
Ratiometric TC
20
ppm/
o
C
V
N
Noise
100kHz / 1kHz
8/24
nV/
H
z
C
H
/C
L
/C
W
Potentiometer Capacitances
8/8/25
pF
fc
Frequency Response
Passive Attenuator, 10k
1.7
MHz
Potentiometer Parameters
CAT5115
5
Doc. No. 2117, Rev. E
V
CC
Range
2.5V
V
CC
5.5V
Input Pulse Levels
0.2V
CC
to 0.7V
CC
Input Rise and Fall Times
10ns
Input Reference Levels
0.5V
CC
AC CONDITIONS OF TEST
A. C. TIMING
(1) Typical values are for T
A
=25
o
C and nominal supply voltage.
(2) This parameter is periodically sampled and not 100% tested.
(3) 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
INC
U
/D
RW
t
CI
t
CYC
t
IL
MI
(3)
90%
90%
10%
(store)
t
F
t
R
t
IW
tID
tDI
t
IH
t
CPH
t
IC
Symbol
Parameter
Min
Typ
(1)
Max
Units
t
CI
CS
to INC Setup
100
--
--
ns
t
DI
U/
D
to
INC
Setup
50
--
--
ns
t
ID
U/
D
to
INC
Hold
100
--
--
ns
t
IL
INC
LOW Period
250
--
--
ns
t
IH
INC
HIGH Period
250
--
--
ns
t
IC
INC
Inactive to
CS
Inactive
1
--
--
s
t
CPH
CS
Deselect Time (NO STORE)
100
--
--
ns
t
CPH
CS
Deselect Time (STORE)
10
--
--
ms
t
IW
INC
to V
OUT
Change
--
1
5
s
t
CYC
INC
Cycle Time
1
--
--
s
t
R,
t
F
(2)
INC
Input Rise and Fall Time
--
--
500
s
t
PU
(2)
Power-up to Wiper Stable
--
--
1
msec
t
WR
Store Cycle
--
5
10
ms
AC OPERATING CHARACTERISTICS:
V
CC
= +2.5V to +5.5V, V
H
= V
CC
, V
L
= 0V
, unless otherwise specified
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