1
FN8184.1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Intersil (and design) is a registered trademark of Intersil Americas Inc.
XDCP is a trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
X9318
Digitally Controlled Potentiometer
(XDCPTM)
FEATURES
Solid-state potentiometer
3-wire serial interface
Terminal voltage, 0 to +8V
100 wiper tap points
--Wiper position stored in nonvolatile memory
and recalled on power-up
99 resistive elements
--Temperature compensated
--End to end resistance range 20%
Low power CMOS
--V
CC
= 5V
--Active current, 3mA max.
--Standby current, 1mA max.
High reliability
--Endurance, 100,000 data changes per bit
--Register data retention, 100 years
R
TOTAL
value = 10k
Packages
--8 Ld SOIC and DIP
Pb-free plus anneal available (RoHS compliant)
APPLICATIONS
LCD bias control
DC bias adjustment
Gain and offset trim
Laser diode bias control
Voltage regulator output control
DESCRIPTION
The Intersil X9318 is a digitally controlled potentiometer
(XDCP). The device consists of a resistor array, wiper
switches, a control section, and nonvolatile memory.
The wiper position is controlled by a 3-wire interface.
The potentiometer is implemented by a resistor array
composed of 99 resistive elements and a wiper switch-
ing network. Between each element and at either end
are tap points accessible to the wiper terminal. The
position of the wiper element is controlled by the CS,
U/D, and INC inputs. The position of the wiper can be
stored in nonvolatile memory and then be recalled
upon a subsequent power-up operation.
The device can be used as a three-terminal potentiome-
ter for voltage control or as a two-terminal variable resis-
tor for current control in a wide variety of applications.
PIN CONFIGURATION
BLOCK DIAGRAM
R
H
V
CC
INC
U/D
1
2
3
4
8
7
6
5
X9318
DIP/SOIC
V
SS
CS
R
L
R
W
Up/Down
Counter
7-Bit
Nonvolatile
Memory
Store and
Recall
Control
Circuitry
One
of
One
Decoder
Resistor
Array
R
H
U/D
INC
CS
Wiper
Switches
Hundred
V
CC
V
SS
R
L
R
W
Control
and
Memory
Up/Down
(U/D)
Increment
(INC)
Device Select
(CS)
V
CC
(Supply Voltage)
V
SS
(Ground)
R
H
R
W
R
L
General
Detailed
0
1
2
96
97
98
99
Data Sheet
September 14, 2005
2
FN8184.1
September 14, 2005
PIN DESCRIPTIONS
Ordering Information
PART NUMBER
PART MARKING
R
TOTAL
(k
)
TEMP RANGE (C)
PACKAGE
X9318WP8
X9318WP
10
0 to 70
8 Ld PDIP
X9318WP8I
X9318WP I
-40 to 85
8 Ld PDIP
X9318WS8*
X9318W
0 to 70
8 Ld SOIC (150 mil)
X9318WS8Z* (Note)
X9318W Z
0 to 70
8 Ld SOIC (150 mil) (Pb-free)
X9318WS8I*
X9318W I
-40 to 85
8 Ld SOIC (150 mil)
X9318WS8IZ* (Note)
X9318W Z I
-40 to 85
8 Ld SOIC (150 mil) (Pb-free)
*Add "T1" suffix for tape and reel.
NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
DIP/SOIC Symbol
Brief Description
1
INC
Increment. Toggling INC while CS is low moves the wiper either up or down.
2
U/D
Up/Down. The U/D input controls the direction of the wiper movement.
3
R
H
The high terminal is equivalent to one of the fixed terminals of a mechanical potentiometer.
4
V
SS
Ground.
5
R
W
The wiper terminal is equivalent to the movable terminal of a mechanical potentiometer.
6
R
L
The low terminal is equivalent to one of the fixed terminals of a mechanical potentiometer.
7
CS
Chip Select. The device is selected when the CS input is LOW, and de-selected when CS is high.
8
V
CC
Supply Voltage.
X9318
3
FN8184.1
September 14, 2005
ABSOLUTE MAXIMUM RATINGS
Junction Temperature under bias...... -65
C to +135
C
Storage temperature ......................... -65C to +150C
Voltage on CS, INC, U/D and V
CC
with respect to V
SS
................................. -1V to +7V
R
H
, R
W
, R
L
to ground..........................................+10V
Lead temperature (soldering 10s) ..................... 300C
I
W
(10s) ..............................................................6mA
COMMENT
Stresses above those listed under "Absolute Maximum
Ratings" may cause permanent damage to the device.
This is a stress rating only; functional operation of the
device (at these or any other conditions above those
listed in the operational sections of this specification) is
not implied. Exposure to absolute maximum rating con-
ditions for extended periods may affect device reliability.
POTENTIOMETER CHARACTERISTICS
(V
CC
= 5V 10%, T
A
= Full Operating Temperature Range unless otherwise stated)
Symbol
Parameter
Limits
Test Conditions/Notes
Min.
Typ.
(4)
Max.
Unit
End to end resistance tolerance
-20
+20
%
See ordering information
for values
V
RH
/
RL
R
H
/R
L
terminal voltage
V
SS
8
V
V
SS
= 0V
Power rating
25
mW
R
W
Wiper resistance
40
200
I
W
= 1mA
I
W
Wiper current
(5)
-3.0
+3.0
mA
See test circuit
Noise
(7)
-120
dBV
Ref: 1kHz
Resolution
1
%
Absolute linearity
(1)
-1
+1
MI
(3)
V(RH) = 8V,
V(RL) = 0V
Relative linearity
(2)
-0.2
+0.2
MI
(3)
R
TOTAL
temperature coefficient
(5)
300
ppm/C
Ratiometric temperature coeffi-
cient
(5),(6)
-20
+20
ppm/C
C
H
/C
L
/C
W
(5
)
Potentiometer capacitances
10/10/25
pF
See equivalent circuit
V
CC
Supply Voltage
4.5
5.5
V
X9318
4
FN8184.1
September 14, 2005
D.C. OPERATING CHARACTERISTICS
(V
CC
= 5V 10%, T
A
= Full Operating Temperature Range unless otherwise stated)
ENDURANCE AND DATA RETENTION
(V
CC
= 5V 10%, T
A
= Full Operating Temperature Range)
Notes: (1) Absolute linearity is utilized to determine actual wiper voltage versus expected voltage = [V(R
W(n)(actual)
) - V(R
W(n)(expected)
)]/MI
V(R
W(n)(expected)
) = n(V(R
H
) - V(R
L
))/99 + V(R
L
), with n from 0 to 99.
(2) Relative linearity is a measure of the error in step size between taps = [V(R
W(n+1)
) - (V(R
W(n)
) - MI)]/MI
(3) 1 Ml = Minimum Increment = [V(R
H
) - V(R
L
)]/99.
(4) Typical values are for T
A
= 25C and nominal supply voltage.
(5) This parameter is not 100% tested.
(6) Ratiometric temperature coefficient = (V(R
W
)
T1(n)
- V(R
W
)
T2(n)
)/[V(R
W
)
T1(n)
(T1 - T2) x 10
6
], with T1 & T2 being 2 temperatures, and n
from 0 to 99.
(7) Measured with wiper at tap position 31, R
L
grounded, using test circuit.
A.C. CONDITIONS OF TEST
Symbol
Parameter
Limits
Unit
Test Conditions
Min.
Typ.
(4)
Max.
I
CC
V
CC
active current (Increment)
1
3
mA
CS = V
IL
, U/D = V
IL
or V
IH
and
INC = 0.4V/2.4V @ min. t
CYC
R
L
, R
H
, R
W
not connected
I
SB
Standby supply current
300
1000
A
CS
2.4V, U/D and INC = 0.4V
R
L
, R
H
, R
W
not connected
I
LI
CS, INC, U/D input leakage current
-10
+10
A
V
IN
= V
SS
to V
CC
V
IH
CS, INC, U/D input HIGH voltage
2
V
CC
+ 1
V
V
IL
CS, INC, U/D input LOW voltage
-1
0.8
V
C
IN
(5)
CS, INC, U/D input capacitance
10
pF
V
CC
= 5V, V
IN
= V
SS
, T
A
= 25C,
f = 1MHz
Parameter
Min.
Unit
Minimum endurance
100,000
Data changes per bit
Data retention
100
Years
Test Circuit
Equivalent Circuit
Force
Current
Test Point
R
W
C
H
C
L
R
W
10pF
10pF
R
TOTAL
C
W
25pF
R
H
R
L
Input pulse levels
0.8V to 2.0V
Input rise and fall times
10ns
Input reference levels
1.4V
X9318
5
FN8184.1
September 14, 2005
A.C. OPERATING CHARACTERISTICS
(V
CC
= 5V 10%, T
A
= Full Operating Temperature Range unless otherwise stated)
POWER-UP AND DOWN REQUIREMENTS
The recommended power-up sequence is to apply V
CC
/V
SS
first, then the potentiometer voltages. During power-up,
the data sheet parameters for the DCP do not fully apply until 1 millisecond after V
CC
reaches its final value. The V
CC
ramp spec is always in effect. In order to prevent unwanted tap position changes, or an inadvertant store, bring the
CS and INC high before or concurrently with the V
CC
pin on powerup.
A.C. TIMING
Symbol
Parameter
Limits
Unit
Min.
Typ.
(4)
Max.
t
Cl
CS to INC setup
100
ns
t
lD
(5)
INC HIGH to U/D change
100
ns
t
DI
(5)
U/D to INC setup
1
s
t
lL
INC LOW period
1
s
t
lH
INC HIGH period
1
s
t
lC
INC inactive to CS inactive
1
s
t
CPHS
CS deselect time (STORE)
20
ms
t
CPHNS
(5
)
CS deselect time (NO STORE)
1
s
t
IW
INC to R
W
change
100
500
s
t
CYC
INC cycle time
4
s
t
R
,
t
F
(5)
INC input rise and fall time
500
s
t
PU
(5)
Power-up to wiper stable
500
s
t
R
V
CC
(5)
V
CC
power-up rate
0.2
50
V/ms
CS
INC
U/D
R
W
t
CI
t
IL
t
IH
t
CYC
t
ID
t
DI
t
IW
MI
(3)
t
IC
t
CPHS
t
F
t
R
10%
90%
90%
t
CPHNS
X9318
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