CAT5136, CAT5137,
CAT5138
Digital Potentiometers (POTs)
with 128 Taps and
I
2
C Interface
Description
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CAT5136, CAT5137, and CAT5138 are a family of digital POTs
operating like mechanical potentiometers in various configurations.
The tap points between the 127 equal resistive elements are connected
to the wiper output via CMOS switches. The switches are controlled
by a 7-bit Wiper Control Register (WCR) via the I
2
C serial bus.
CAT5136 is configured as a variable resistor. CAT5137 and CAT5138
are resistive voltage dividers, with one terminal of the potentiometer
connected to GND. CAT5137 and CAT5138 have different device IDs,
which makes it possible to use both on the same I
2
C bus. Upon
power-up, the WCR is set to mid-scale (1000000).
Features
SC−70
SD SUFFIX
CASE 419AD
PIN CONNECTIONS
(for low pin count devices)
VDD 1
GND 2
SCL 3
CAT5136
VDD
GND
SCL
1
2
3
CAT5137
CAT5138
(Top Views)
See detailed pin function descriptions on page 2.
6 RH
5 RW
4 SDA
6 RL
5 RW
4
SDA
Single Linear Digital Potentiometer with 128 Taps
End-to-End Resistance of 10 kW, 50 kW and 100 kW
I
2
C Interface
Wiper goes to Midscale at Power-up
Digital Supply Range (V
DD
): 2.7 V to 5.5 V
Low Standby Current
Industrial Temperature Range:
−40C
to +85C
6-pin SC−70 Package
These Devices are Pb-Free, Halogen Free/BFR Free and are RoHS
Compliant
LCD Screen Adjustment
Volume Control
Mechanical Potentiometer Replacement
Gain Adjustment
Line Impedance Matching
VCOM Setting Adjustments
Typical Applications
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 9 of this data sheet.
Semiconductor Components Industries, LLC, 2013
July, 2013
−
Rev. 1
1
Publication Order Number:
CAT5136/D
CAT5136, CAT5137, CAT5138
VDD
I
2
C
Interface
and
Control
Power On
Midscale
VDD
RH
RW
SCL
SDA
SCL
RW
RL
SDA
I
2
C
Interface
and
Control
Power On
Midscale
GND
(CAT5136)
GND
(CAT5137, CAT5138)
Figure 1. Block Diagram
Table 1. PIN FUNCTION DESCRIPTION
Pin No.
CAT5136
1
2
3
4
CAT5137/CAT5138
1
2
3
4
Pin Name
VDD
GND
SCL
SDA
Description
Digital Supply Voltage (2.7 V to 5.5 V)
Ground
Serial Bus Clock input for the I
2
C Serial Bus. This clock is used to clock all data
transfers into and out of the CAT5136−8
Serial Data Input/Output
−
Bidirectional Serial Data pin used to transfer data into
and out of the CAT5136−8. This is an Open-Drain I/O and can be wire OR’d with
other Open-Drain (or Open Collector) I/Os.
Wiper Terminal for the potentiometer
Low Reference Terminal for the potentiometer
High Reference Terminal for the potentiometer
5
6
−
5
−
6
RW
RL
RH
Table 2. ABSOLUTE MAXIMUM RATINGS
Parameter
Temperature Under Bias
Storage Temperature Range
Voltage on any SDA, SCL, A0 & A1 pins with respect to Ground (Note 1)
Voltage on RH, RL & RW pins with respect to Ground
V
DD
with respect to Ground
Wiper Current (10 sec)
Lead Soldering temperature (10 sec)
T
STG
Symbol
Range
−55
to +125
−65
to 150
−0.3
to V
DD
+ 0.3
−0.3
to V
DD
+ 0.3
−0.3
to +6
6
+300
Unit
C
C
V
V
V
mA
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.
1. Latch-up protection is provided for stresses up to 100 mA on address and data pins from
−0.3
V to V
DD
+0.3 V.
Table 3. RECOMMENDED OPERATION CONDITIONS
Parameter
Digital Supply Voltage
Operating Temperature Range
Symbol
V
DD
Value
+2.7 to +5.5
−40
to +85
Unit
V
C
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CAT5136, CAT5137, CAT5138
Table 4. POTENTIOMETERS CHARACTERISTICS
(Over recommended operating conditions unless otherwise stated.)
Limits
Parameter
Potentiometer Resistance (10 kW)
Potentiometer Resistance (50 kW)
Potentiometer Resistance (100 kW)
Potentiometer Resistance Tolerance
Power Rating
Wiper Current
Wiper Resistance
Voltage on R
W
, R
H
or R
L
Resolution
Integral Non-Linearity (Note 3)
Differential Non-Linearity (Note 4)
Resistor Integral Non-Linearity
Resistor Differential Non-Linearity
Temperature Coefficient of R
POT
Ratiometric Temperature Coefficient
Potentiometer Capacitances
Frequency Response
I
W
R
W
V
TERM
RES
INL
DNL
R
INL
R
DNL
T
CRPOT
T
CRatio
C
H
/C
L
/C
W
fc
V
W(n)(actual)
−
V
W(n)(expected)
(Notes 6, 7)
V
W(n+1)
−
[V
W(n)
+LSB] (Notes 6, 7)
R
n
−
n*LSB (Notes 6, 8)
R
n
−
[R
n−1
+ LSB] (Notes 6, 8)
(Note 2)
(Note 2)
(Note 2)
R
POT
10/10/25
0.4
300
30
V
DD
= 3.3 V
GND = 0 V; V
DD
= 2.7 V to +5.5 V
GND
0.78
1
1
2
1
85
Symbol
R
POT
R
POT
R
POT
R
TOL
25C
Test Conditions
Min
Typ
10
50
100
20
50
3
200
V
DD
Max
Units
kW
kW
kW
%
mW
mA
W
V
%
LSB
(Note 5)
LSB
(Note 5)
LSB
(Note 5)
LSB
(Note 5)
ppm/C
ppm/C
pF
MHz
2. This parameter is tested initially and after a design or process change that affects the parameter.
3. Integral Non-Linearity is utilized to determine actual wiper voltage versus expected voltage as determined by wiper position when used as
a potentiometer.
4. Differential Non-Linearity is utilized to determine the actual change in voltage between two successive tap positions when used as a
potentiometer.
5. LSB = (R
HM
−
R
LM
)/127; where R
HM
and R
LM
are the highest and lowest measured values on the wiper terminal.
6. n = 1, 2, ..., 127
7. V
DD
@ R
H
; V
W
measured @ R
W
with no load.
8. Rw and R
L
in the range of 0 V and V
DD
.
Table 5. D.C. ELECTRICAL CHARACTERISTICS
(Over recommended operating conditions unless otherwise stated.)
Parameter
Power Supply Current
(Write/Read)
Standby Current
Input Leakage Current
Output Leakage Current
Input Low Voltage
Input High Voltage
Output Low Voltage (V
DD
= 3.0 V)
Symbol
I
DD
I
SB(VDD)
I
LI
I
LO
V
IL
V
IH
V
OL
I
OL
= 3 mA
Test Conditions
F
SCL
= 400 kHz, SDA Open,
V
DD
= 5.5 V, Input = GND
V
IN
= GND or V
DD
, SDA = V
DD
V
IN
= GND to V
DD
V
OUT
= GND to V
DD
−1
−1
−0.3
V
DD
x 0.7
Min
Max
200
0.5
1
1
V
DD
x 0.3
V
DD
+ 0.3
0.4
Units
mA
mA
mA
mA
V
V
V
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CAT5136, CAT5137, CAT5138
Table 6. A.C. CHARACTERISTICS
Parameter
(see Figure 6)
Clock Frequency
Noise Suppression Time Constant at SCL & SDA Inputs
SCL Low to SDA Data Out and ACK Out
Time the bus must be free before a new transmission can start
Start Condition Hold Time
Clock Low Period
Clock High Period
Start Condition Setup Time (for a Repeated Start Condition)
Data In Setup Time
Data in Hold Time
SDA and SCL Rise Time
SDA and SCL Fall Time
Stop Conditions Setup Time
Data Out Hold Time
Symbol
F
SCL
T
I
(Note 9)
t
AA
t
BUF
(Note 9)
t
HD:STA
t
LOW
t
HIGH
t
SU:STA
t
SU:DAT
t
HD:DAT
t
R
(Note 9)
t
F
(Note 9)
t
SU:STO
t
DH
0.6
100
1.2
0.6
1.2
0.6
0.6
100
0
0.3
300
Min
Typ
Max
400
50
1
Units
kHz
ns
ms
ms
ms
ms
ms
ms
ns
ms
ms
ns
ms
ns
9. This parameter is tested initially and after a design or process change that affects the parameter.
Table 7. CAPACITANCE
(T
A
= 25C, f = 1.0 MHz, V
DD
= 5.0 V)
Parameter
Input/Output Capacitance (SDA, SDC)
Symbol
C
I/O
Test Conditions
V
I/O
= 0 V (Note 10)
Min
Typ
Max
10
Unit
pF
10. This parameter is tested initially and after a design or process change that affects the parameter.
Table 8. POWER-UP TIMING
(Notes 11, 12)
Symbol
t
PUR
t
PUW
Power-up to Read Operation
Power-up to Write Operation
Parameter
Min
Max
1
1
Units
ms
ms
11. This parameter is tested initially and after a design or process change that affects the parameter.
12. t
PUR
and t
PUW
are the delays required from the time V
DD
is stable until the specified operation can be initiated.
Table 9. WIPER TIMING
Symbol
t
WRPO
t
WRL
Parameter
Wiper Response Time After Power Supply Stable
Wiper Response Time After Instruction Issued
Min
5
5
Max
10
10
Units
ms
ms
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CAT5136, CAT5137, CAT5138
TYPICAL PERFORMANCE CHARACTERISTICS
60
50
40
R
WL
(kW)
I
CC
(mA)
30
20
10
0
Rheostat Configuration
T
A
= +25C, R
POT
= 50 kW
0
16
32
48
64
80
96
112
128
V
CC
= 2.7 V
V
CC
= 5.5 V
90
80
70
60
50
40
30
20
10
0
2
3
4
V
CC
(V)
5
6
−40C
25C
90C
125C
TAP POSITION
Figure 2. Resistance between R
W
and R
L
1.0
0.8
0.6
0.4
DNL (LSB)
INL (LSB)
0.2
0
−0.2
−0.4
−0.6
−0.8
−1.0
V
CC
= 2.7 V
V
CC
= 5.5 V
0
16
32
48
64
80
96
112
128
Potentiometer Configuration
T
A
= +25C, R
POT
= 10 kW
1.0
0.8
0.6
0.4
0.2
0
−0.2
−0.4
−0.6
−0.8
−1.0
Figure 3. Power Supply Current
Potentiometer Configuration
V
CC
= 2.7 V
V
CC
= 5.5 V
0
16
32
48
64
80
96
112
128
TAP POSITION
TAP POSITION
Figure 4. Integral Non−Linearity
Figure 5. Differential Non−Linearity
t
F
t
LOW
SCL
t
SU:STA
SDA IN
t
AA
SDA OUT
t
HD:STA
t
HIGH
t
LOW
t
R
t
HD:DAT
t
SU:DAT
t
SU:STO
t
DH
t
BUF
Figure 6. Bus Timing
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