Digitally Controlled Potentiometer (XDCP
™
)
FEATURES
•
•
•
•
Solid-state potentiometer
3-wire serial interface
Terminal voltage, 0 to +10V
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
Ω
and 50K
Ω
Packages
—8-lead SOIC and DIP
DESCRIPTION
X9319
The Xicor X9319 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
potentiometer for voltage control or as a two-terminal
variable resistor for current control in a wide variety of
applications.
•
•
•
•
•
APPLICATIONS
•
•
•
•
•
LCD bias control
DC bias adjustment
Gain and offset trim
Laser diode bias control
Voltage regulator output control
BLOCK DIAGRAM
U/D
INC
CS
Up/Down
Counter
99
98
97
7-Bit
Nonvolatile
Memory
96
One
of
One
Hundred
Decoder
2
V
SS
(Ground)
General
V
CC
V
SS
Store and
Recall
Control
Circuitry
1
0
R
L
R
W
Detailed
XDCP is a trademark of Xicor, Inc.
R
H
V
CC
(Supply Voltage)
Up/Down
(U/D)
Increment
(INC)
Device Select
(CS)
Control
and
Memory
R
H
R
W
Wiper
Switches
Resistor
Array
R
L
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X9319
PIN CONFIGURATION
DIP/SOIC
INC
U/D
R
H
V
SS
1
2
3
4
X9319
8
7
6
5
V
CC
CS
R
L
R
W
ORDERING INFO
Ordering
Number
X9319WS8
X9319WS8I
X9319WP8
X9319WP8I
X9319US8
X9319US8I
X9319UP8
X9319UP8I
RTOTAL
10K
Ω
10K
Ω
10K
Ω
10K
Ω
50K
Ω
50K
Ω
50K
Ω
50K
Ω
8-lead SOIC
8-lead SOIC
8-lead Plastic DIP
8-lead Plastic DIP
8-lead SOIC
8-lead SOIC
8-lead Plastic DIP
8-lead Plastic DIP
Package
Operating Temperature
Range
0°C to 70°C
-40°C to +85°C
0°C to 70°C
-40°C to +85°C
0°C to 70°C
-40°C to +85°C
0°C to 70°C
-40°C to +85°C
PIN DESCRIPTIONS
DIP/
SOIC
1
2
3
4
5
6
7
8
Symbol
INC
U/D
R
H
V
SS
R
W
R
L
CS
V
CC
Brief Description
Increment
. Toggling INC while CS is low moves the wiper either up or down.
Up/Down
. The U/D input controls the direction of the wiper movement.
The high terminal is equivalent to one of the fixed terminals of a mechanical potentiometer.
Ground.
The wiper terminal is equivalent to the movable terminal of a mechanical potentiometer.
The low terminal is equivalent to one of the fixed terminals of a mechanical potentiometer.
Chip Select
. The device is selected when the CS input is LOW, and de-selected when CS is
high.
Supply Voltage.
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X9319
ABSOLUTE MAXIMUM RATINGS
Junction Temperature under bias ......–65
°
C to +135
°
C
Storage temperature .........................–65°C to +150°C
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 .......................................... +12V
Lead temperature (soldering 10 seconds)..........300°C
I
W
(10 seconds) ................................................. ±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)
Limits
Symbol
Parameter
End to end resistance tolerance
V
RH
/
RL
R
W
I
W
R
H
/R
L
terminal voltage
Power rating
Wiper resistance
Wiper current
(5)
Noise
(7)
Resolution
Absolute linearity
(1)
Relative linearity
(2)
R
TOTAL
temperature coefficient
(5)
Ratiometric temperature coefficient
(5),(6)
C
H
/C
L
/C
W
(5)
Potentiometer capacitances
V
CC
Supply Voltage
4.5
-20
10/10/25
5.5
-1
-0.2
±300
+20
-3.0
-120
1
+1
+0.2
40
Min.
-20
V
SS
Typ.
(4)
Max.
+20
10
25
200
+3.0
Unit
%
V
mW
Ω
mA
dBV
%
MI
(3)
MI
(3)
ppm/°C
ppm/°C
pF
V
Test Conditions/Notes
See ordering information
for values
V
SS
= 0V
I
W
= 1mA
See test circuit
Ref: 1kHz
V(RH) = 10V,
V(RL) = 0V
See equivalent circuit
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X9319
D.C. OPERATING CHARACTERISTICS
(V
CC
= 5V ±10%, T
A
= Full Operating Temperature Range unless otherwise stated)
Limits
Symbol
I
CC
Parameter
V
CC
active current (Increment)
Min.
Typ.
(4)
1
Max.
3
Unit
mA
Test Conditions
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
CS
≥
2.4V, U/D and INC = 0.4V
R
L
, R
H
, R
W
not connected
V
IN
= V
SS
to V
CC
I
SB
I
LI
V
IH
V
IL
C
IN(5)
Standby supply current
CS, INC, U/D input leakage
current
CS, INC, U/D input HIGH voltage
CS, INC, U/D input LOW voltage
CS, INC, U/D input capacitance
-10
2
–1
300
1000
+10
V
CC
+ 1
0.8
10
µA
µA
V
V
pF
V
CC
= 5V, V
IN
= V
SS
, T
A
= 25°C,
f = 1MHz
ENDURANCE AND DATA RETENTION
(V
CC
= 5V ±10%, T
A
= Full Operating Temperature Range)
Parameter
Minimum endurance
Data retention
Min.
100,000
100
Unit
Data changes per bit
Years
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
= 25°C and nominal supply voltage.
(5) Guaranteed by device characterization.
(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.
Test Circuit
Equivalent Circuit
R
TOTAL
R
H
C
H
Force
Current
10pF
R
W
C
W
25pF
C
L
10pF
R
L
Test Point
R
W
A.C. CONDITIONS OF TEST
Input pulse levels
Input rise and fall times
Input reference levels
REV 1.7 7/10/03
0.8V to 2.0V
10ns
1.4V
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X9319
A.C. OPERATING CHARACTERISTICS
(V
CC
= 5V ±10%, T
A
= Full Operating Temperature Range unless otherwise stated)
Limits
Symbol
t
Cl
t
lD(5)
t
DI(5)
t
lL
t
lH
t
lC
t
CPHS
t
CPHNS(5)
t
IW(5)
t
CYC
t
R,
t
F(5)
t
PU(5)
t
R
V
CC(5)
CS to INC setup
INC HIGH to U/D change
U/D to INC setup
INC LOW period
INC HIGH period
INC inactive to CS inactive
CS deselect time (STORE)
CS deselect time (NO STORE)
INC to R
W
change
INC cycle time
INC input rise and fall time
Power up to wiper stable
V
CC
power-up rate
0.2
4
500
500
50
Parameter
Min.
100
100
1
1
1
1
20
1
Typ.
(4)
Max.
Unit
ns
ns
µs
µs
µs
µs
ms
µs
100
500
µs
µs
µs
µs
V/ms
POWER UP AND DOWN REQUIREMENTS
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. The potentiometer voltages must be applied after this sequence is com-
pleted. 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.
A.C. TIMING
CS
t
CYC
t
CI
INC
t
ID
t
DI
t
F
t
IL
t
IH
t
IC
t
CPHS
90% 90%
10%
t
R
t
CPHNS
U/D
t
IW
R
W
MI
(3)
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