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Low Noise, Low Power, 100 Taps
X9317
Digitally Controlled Potentiometer (XDCP
™
)
FEATURES
• Nonvolatile solid state potentiometer
• Single device
• 100 resistor taps
• 3-wire serial up/down interface
• Wiper resistance 200
Ω
typ. at 5V
•R
TOTAL
values = 1k
Ω
, 10k
Ω
, 50k
Ω
• Standby current < 1
µ
A
•V
CC
= 5V and 2.7V to 5.5V
• Endurance = 100,000 cycles
• Data retention = 100 years
• Packages – 8-lead DIP, SOIC, TSSOP, MSOP
DESCRIPTION
The Xicor X9317 is a nonvolatile digitally controlled
potentiometer (XDCP). The device consists of a poly-
crystalline resistor array of 99 segments and CMOS
switches that connect the wiper terminal to any one of
the 100 nodes in the array of resistors. The wiper posi-
tion is defined by the data that is transmitted to the
device on the 3 terminal serial Up/Down port. A pulse
on the increment pin causes the wiper to move one
step to the next wiper position. The direction the wiper
moves is defined by the logic state on the Up/Down
pin. A rising edge on the Chip Select pin while the
increment pin is high causes the present wiper posi-
tion to be written into an EPROM register. This value is
recalled on power up restoring the last wiper position
that was written into the register.
The device can be used in the two terminal mode, with
the wiper connected to one end of the total resistor, as
a variable resistor or can be used in the three terminal
mode as a programmable voltage reference. The
X9317 can be used to program offset voltages or set
gains on amplifiers in control circuits.
BLOCK DIAGRAM
7-Bit
Up/Down
Counter
7-Bit
Nonvolatile
Memory
Store and
Recall
Control
Circuitry
One
of
One
Decoder
Resistor
Array
RH/VH
U/D
INC
CS
Transfer
Gates
Hundred
VCC
VSS
RL/VL
RW/VW
Control
and
Memory
Up/Down
(U/D)
Increment
(INC)
Device Select
(CS)
VCC (Supply Voltage)
VSS (Ground)
RH/VH
RW/VW
RL/VL
General
Detailed
0
1
2
96
97
98
99
A
PPLICATION
N
OTE
A V A I L A B L E
AN20 • AN42–53 • AN71 • AN73 • AN88 • AN91–92 • AN99 • AN115 • AN120 • AN124 • AN133 • AN134
X9317
Characteristics subject to change without notice.
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PIN DESCRIPTIONS
R
H
/V
H
and R
L
/V
L
The high (R
H
/V
H
) and low (R
L
/V
L
) terminals of the
X9317 are equivalent to the fixed terminals of a
mechanical potentiometer. The minimum voltage is
V
SS
and the maximum is V
CC
. The terminology of R
L
/
V
L
and R
H
/V
H
references the relative position of the
terminal in relation to wiper movement direction
selected by the U/D input and not the voltage potential
on the terminal.
R
W
/V
W
R
w
/V
w
is the wiper terminal and is equivalent to the
movable terminal of a mechanical potentiometer. The
position of the wiper within the array is determined by
the control inputs. The wiper terminal series resistance
is typically 200
Ω
when V
CC
= 5V.
Up/Down (U/D)
The U/D input controls the direction of the wiper move-
ment and whether the counter is incremented or dec-
remented.
Increment (INC)
The INC input is negative-edge triggered. Toggling
INC will move the wiper and either increment or decre-
ment the counter in the direction indicated by the logic
level on the U/D input.
Chip Select (CS)
The device is selected when the CS input is LOW. The
current counter value is stored in nonvolatile memory
when CS is returned HIGH while the INC input is also
HIGH. After the store operation is complete the X9317
will be placed in the low power standby mode until the
device is selected once again.
PIN CONFIGURATION
PIN NAMES
Symbol Description
R
H
/V
H
High Terminal
R
W
/V
W
Wiper Terminal
R
L
/V
L
Low Terminal
V
SS
Ground
V
CC
Supply Voltage
U/D Up/Down Control Input
INC Increment Control Input
CS Chip Select Control Input
RH/VH
VCC
INC
U/D
1
2
3
4
8
7
6
5
X9317
DIP/SOIC/MSOP
VSS
CS
RL/VL
RW/VW
VSS
CS
VCC
INC
U/D
1
2
3
4
8
7
6
5
X9317
TSSOP
RH/VH
RL/VL
RW/VW
X9317
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PRINCIPLES OF OPERATION
There are three sections of the X9317: the input con-
trol, counter and decode section; the nonvolatile mem-
ory; and the resistor array. The input control section
operates just like an up/down counter. The output of
this counter is decoded to turn on a single electronic
switch connecting a point on the resistor array to the
wiper output. Under the proper conditions the contents
of the counter can be stored in nonvolatile memory
and retained for future use. The resistor array is com-
prised of 99 individual resistors connected in series. At
either end of the array and between each resistor is an
electronic switch that transfers the potential at that
point to the wiper.
The wiper, when at either fixed terminal, acts like its
mechanical equivalent and does not move beyond the
last position. That is, the counter does not wrap
around when clocked to either extreme.
The electronic switches on the device operate in a
“make before break” mode when the wiper changes
tap positions. If the wiper is moved several positions,
multiple taps are connected to the wiper for t
IW
(INC to
V
W
change). The R
TOTAL
value for the device can tem-
porarily be reduced by a significant amount if the wiper
is moved several positions.
When the device is powered-down, the last wiper posi-
tion stored will be maintained in the nonvolatile mem-
ory. When power is restored, the contents of the
memory are recalled and the wiper is set to the value
last stored.
INSTRUCTIONS AND PROGRAMMING
The INC, U/D and CS inputs control the movement of
the wiper along the resistor array. With CS set LOW,
the device is selected and enabled to respond to the
U/D and INC inputs. HIGH to LOW transitions on INC
will increment or decrement (depending on the state of
the U/D input) a seven bit counter. The output of this
counter is decoded to select one of one hundred wiper
positions along the resistive array.
The value of the counter is stored in nonvolatile mem-
ory whenever CS transitions HIGH while the INC input
is also HIGH.
The system may select the X9317, move the wiper,
and deselect the device without having to store the lat-
est wiper position in nonvolatile memory. After the
wiper movement is performed as described above and
once the new position is reached, the system must
keep INC LOW while taking CS HIGH. The new wiper
will would be maintained until changed by the system
or until a power-up/down cycle recalled the previously
stored data.
This procedure allows the system to always power-up
to a preset value stored in nonvolatile memory; then
during system operation minor adjustments could be
made. The adjustments might be based on user pref-
erence, system parameter changes due to tempera-
ture drift, etc...
The state of U/D may be changed while CS remains
LOW. This allows the host system to enable the device
and then move the wiper up and down until the proper
trim is attained.
MODE SELECTION
SYMBOL TABLE
CS INC U/D Mode
L H Wiper Up
L L Wiper Down
H X Store Wiper Position
H X X Standby Current
L X No Store, Return to Standby
WAVEFORM INPUTS OUTPUTS
Must be
steady Will be
steady
May change
from Low to
High
Will change
from Low to
High
May change
from High to
Low
Will change
from High to
Low
Don’t Care:
Changes
Allowed
Changing:
State Not
Known
N/A Center Line
is High
Impedance
X9317
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ABSOLUTE MAXIMUM RATINGS
Temperature under bias ....................–65
°
C to +135
°
C
Storage temperature .........................–65°C to +150°C
Voltage on CS, INC, U/D, V
H
, V
L
and
V
CC
with respect to V
SS
.........................–1V to +7V
∆
V = |V
H
–V
L
|........................................................... 5V
Lead temperature (soldering 10 seconds)..........300°C
I
W
(10 seconds) ................................................ 8.8mA
COMMENT
Stresses above those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device.
This is a stress rating only and the functional operation
of the device at these or any other conditions above
those listed in the operational sections of this specifi-
cation is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect
device reliability.
RECOMMENDED OPERATING CONDITIONS
Temperature Min. Max.
Commercial 0°C +70°C
Industrial –40°C +85°C
Supply Voltage (V
CC
) Limits
X9317 5V ±10%
X9317-2.7 2.7V to 5.5V
POTENTIOMETER CHARACTERISTICS
(Over recommended operating conditions unless otherwise stated.)
Notes:
(1) Absolute Linearity is utilized to determine actual wiper voltage versus expected voltage = (V
w(n)
(actual)–V
w(n)
(expected)) = ±1 Ml
Maximum.
(2) Relative Linearity is a measure of the error in step size between taps = V
W(n+1)
–[V
w(n)
+ Ml] = ±0.2 Ml.
(3) 1 Ml = Minimum Increment = R
TOT
/99.
(4) Typical values are for T
A
= 25°C and nominal supply voltage.
(5) This parameter is periodically sampled and not 100% tested.
Symbol Parameter
Limits
Test Conditions/NotesMin. Typ. Max. Unit
R
TOTAL End to End Resistance Variation ±20 %
VVH/RH VH Terminal Voltage VSS VCC VV
SS = 0V
VVL/RL VL Terminal Voltage VSS VCC VV
SS = 0V
Power Rating 10 mW RTOTAL ≥ 10 KΩ
Power Rating 25 mW RTOTAL = 1 KΩ
RWWiper Resistance 200 400 ΩIW = 1mA, VCC = 5V
RWWiper Resistance 400 1000 ΩIW = 1mA, VCC = 2.7V
IWWiper Current ±4.4 mA
Noise -120 dBV Ref: 1kHz
Resolution 1 %
Absolute Linearity(1) ±1 MI(3) Vw(n)(actual)–Vw(n)(expected)
Relative Linearity(2) ±.2 MI(3) Vw(n+1)–[Vw(n)+MI]
RTOTAL Temperature Coefficient ±300 ppm/°C
Ratiometric Temperature Coefficient ±20 ppm/°C
CH/CL/CWPotentiometer Capacitances 10/10/
25 pF See circuit #3
X9317
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D.C. OPERATING CHARACTERISTICS (Over recommended operating conditions unless otherwise specified.)
ENDURANCE AND DATA RETENTION
Symbol Parameter
Limits
Unit Test ConditionsMin. Typ.(4) Max.
ICC1 VCC Active Current
(Increment) 50 µA CS = VIL, U/D = VIL or VIH and
INC = 0.4V/2.4V @ max. tCYC
ICC2 VCC Active Current
(Store) (EEPROM Store) 400 µA CS = VIH, U/D = VIL or VIH and
INC = VIH @ max. tWR
ISB Standby Supply Current 1 µA CS = VCC – 0.3V, U/D and INC
= VSS or VCC – 0.3V
ILI CS, INC, U/D Input ±10 µA VIN = VSS to VCC
Leakage Current
VIH CS, INC, U/D Input VCC x 0.7 VCC + 0.5 V
HIGH Voltage
VIL CS, INC, U/D Input –0.5 VCC x 0.1 V
LOW Voltage
CIN(5) CS, INC, U/D Input 10 pF VCC = 5V, VIN = VSS,
Capacitance TA = 25°C, f = 1MHz
Parameter Min. Unit
Minimum endurance 100,000 Data changes per bit per bit
Data retention 100 Years
Test Circuit #2
Force
Current
VW
VH
Test Point
VL
Test Circuit #1
Test Point
VW/RW
VH/RH
VL/RL
VS
Circuit #3 SPICE Macro Model
CH
CL
RW
10pF
10pF
RHRL
RTOTAL
CW
25pF
X9317
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A.C. CONDITIONS OF TEST
Input pulse levels 0V to 3V
Input rise and fall times 10ns
Input reference levels 1.5V
A.C. OPERATING CHARACTERISTICS (Over recommended operating conditions unless otherwise specified)
A.C. TIMING
Notes: (6) Typical values are for TA = 25°C and nominal supply voltage.
(7) This parameter is periodically sampled and not 100% tested.
(8) MI in the A.C. timing diagram refers to the minimum incremental change in the VW output due to a change in the wiper position.
Symbol Parameter
Limits
UnitsMin. Typ.(6) Max.
tCl CS to INC Setup 100 ns
tlD INC HIGH to U/D Change 100 ns
tDI U/D to INC Setup 2.9 µs
tlL INC LOW Period 1 µs
tlH INC HIGH Period 1 µs
tlC INC Inactive to CS Inactive 1 µs
tCPH CS Deselect Time (NO STORE) 100 ns
tCPH CS Deselect Time (STORE) 10 ms
tIW INC to VW Change 1 5 µs
tCYC INC Cycle Time 4 µs
tR, tF(7) INC Input Rise and Fall Time 500 µs
tPU(7) Power up to Wiper Stable 5 µs
tR VCC(7) VCC Power-up Rate 0.2 50 V/ms
tWR Store Cycle 5 10 ms
CS
INC
U/D
VW
tCI tIL tIH
tCYC
tID tDI
tIW
MI (8)
tIC tCPH
tFtR
10%
90% 90%
(store)
X9317
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PERFORMANCE CHARACTERISTICS (TYPICAL)
Typical Total Resistance Temperature Coefficient
-55
-350
-300
-250
-200
-150
-100
-50
0
-45 -35 -25 -15 -5 5 15 25 35
Temperature (°C)
PPM
45 55 65 75 85 95 105 115 125
X9317
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APPLICATIONS INFORMATION
Electronic digitally-controlled (XDCP) potentiometers provide three powerful application advantages; (1) the vari-
ability and reliability of a solid-state potentiometer, (2) the flexibility of computer-based digital controls, and (3) the
retentivity of nonvolatile memory used for the storage of multiple potentiometer settings or data.
Basic Configurations of Electronic Potentiometers
Basic Circuits
VR
VW/RW
VR
I
Three terminal potentiometer;
variable voltage divider Two terminal variable resistor;
variable current
VH/RH
VL/RL
Cascading TechniquesBuffered Reference Voltage
–
+
+5V
R1
+V
–5V
VW
VREF VOUT
OP-07
VW/RW
VW/RW
+V
+V +V
X
(a) (b)
VOUT = VW/RW
Noninverting Amplifier
VO = (1+R2/R1)VS
Voltage Regulator
R1
R2
Iadj
VO (REG) = 1.25V (1+R2/R1)+Iadj R2
VO (REG)VIN 317
Offset Voltage Adjustment
+
–
VS
VO
R2
R1
100KΩ
10KΩ10KΩ
10KΩ
-12V+12V
TL072
Comparator with Hysteresis
VUL = {R1/(R1+R2)} VO(max)
VLL = {R1/(R1+R2)} VO(min)
+
–
VSVO
R2
R1
LM308A
+5V
–5V
+
–
VSVO
R2
R1
}
}
(for additional circuits see AN115)
LT311A
X9317
Characteristics subject to change without notice. 9 of 14
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PACKAGING INFORMATION
NOTE:
1. ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS)
2. PACKAGE DIMENSIONS EXCLUDE MOLDING FLASH
0.020 (0.51)
0.016 (0.41)
0.150 (3.81)
0.125 (3.18)
0.110 (2.79)
0.090 (2.29)
0.430 (10.92)
0.360 (9.14)
0.300
(7.62) Ref.
Pin 1 Index
0.145 (3.68)
0.128 (3.25)
0.025 (0.64)
0.015 (0.38)
Pin 1
Seating
0.065 (1.65)
0.045 (1.14)
0.260 (6.60)
0.240 (6.10)
0.060 (1.52)
0.020 (0.51)
Typ. 0.010 (0.25)
0°
15°
8-Lead Plastic Dual In-Line Package Type P
Half Shoulder Width On
All End Pins Optional
.073 (1.84)
Max.
0.325 (8.25)
0.300 (7.62)
Plane
X9317
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PACKAGING INFORMATION
0.150 (3.80)
0.158 (4.00)
0.228 (5.80)
0.244 (6.20)
0.014 (0.35)
0.019 (0.49)
Pin 1
Pin 1 Index
0.010 (0.25)
0.020 (0.50)
0.050 (1.27)
0.188 (4.78)
0.197 (5.00)
0.004 (0.19)
0.010 (0.25)
0.053 (1.35)
0.069 (1.75)
(4X) 7°
0.016 (0.410)
0.037 (0.937)
0.0075 (0.19)
0.010 (0.25)
0° - 8°
X 45°
8-Lead Plastic Small Outline Gull Wing Package Type S
NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS)
0.250"
0.050"Typical
0.050"
Typical
0.030"
Typical
8 PlacesFOOTPRINT
X9317
Characteristics subject to change without notice. 11 of 14
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PACKAGING INFORMATION
NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS)
8-Lead Plastic, TSSOP, Package Type V
See Detail “A”
.031 (.80)
.041 (1.05)
.169 (4.3)
.177 (4.5) .252 (6.4) BSC
.025 (.65) BSC
.114 (2.9)
.122 (3.1)
.002 (.05)
.006 (.15)
.047 (1.20)
.0075 (.19)
.0118 (.30)
0° – 8°
.010 (.25)
.019 (.50)
.029 (.75)
Gage Plane
Seating Plane
Detail A (20X)
(4.16) (7.72)
(1.78)
(0.42)
(0.65)
All Measurements Are Typical
X9317
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PACKAGING INFORMATION
0.118 ± 0.002
(3.00 ± 0.05)
0.040 ± 0.002
(1.02 ± 0.05)
0.150 (3.81)
Ref.
0.193 (4.90)
0.030 (0.76)
0.036 (0.91)
0.032 (0.81)
0.007 (0.18)
0.005 (0.13)
0.008 (0.20)
0.004 (0.10)
0.0216 (0.55)
7° Typ.
R 0.014 (0.36)
0.118 ± 0.002
(3.00 ± 0.05)
0.012 + 0.006 / -0.002
(0.30 + 0.15 / -0.05) 0.0256 (0.65) Typ.
M Package
NOTE:
1. ALL DIMENSIONS IN INCHES AND (MILLIMETERS)
0.220"
0.0256" Typical
0.025"
Typical
0.020"
Typical
8 PlacesFOOTPRINT
Ref.
8-Lead Miniature Small Outline Gull Wing Package Type MSOP
X9317
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ORDERING INFORMATION
Physical Characteristics
Marking Includes
Manufacturer’s Trademark
Resistance Value or Code
Date Code
VCC Limits
Blank = 5V ±10%
–2.7 = 2.7V to 5.5V
Temperature Range
Blank = Commercial = 0°C to +70°C
I = Industrial = –40°C to +85°C
Package
P = 8-Lead Plastic Dip
S8 = 8-Lead SOIC
V8 = 8-Lead TSSOP
M8 = 8-Lead MSOP
End to End Resistance
W =10KΩ
U = 50KΩ
Z = 1KΩ (S8 & V8 pkg only)
X9317X X X X
MSOP Part No. Mark
X9317WM8 ABF
X9317WM8-2.7 ACZ
X9317WM8I ADS
X9317WM8I-2.7 ADT
X9317UM8 AEC
X9317UM8-2.7 AED
X9317UM8I AFE
X9317UM8I-2.7 AFF
X9317ZM8 AFG
X9317ZM8-2.7 AFH
X9317ZM8I AFI
X9317ZM8I-2.7 AFJ
X9317
Characteristics subject to change without notice. 14 of 14
LIMITED WARRANTY
Devices sold by Xicor, Inc. are covered by the warranty and patent indemnification provisions appearing in its Terms of Sale only. Xicor, Inc. makes no warranty,
express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement.
Xicor, Inc. makes no warranty of merchantability or fitness for any purpose. Xicor, Inc. reserves the right to discontinue production and change specifications and prices
at any time and without notice.
Xicor, Inc. assumes no responsibility for the use of any circuitry other than circuitry embodied in a Xicor, Inc. product. No other circuits, patents, or licenses are implied.
TRADEMARK DISCLAIMER:
Xicor and the Xicor logo are registered trademarks of Xicor, Inc. AutoStore, Direct Write, Block Lock, SerialFlash, MPS, and XDCP are also trademarks of Xicor, Inc. All
others belong to their respective owners.
U.S. PATENTS
Xicor products are covered by one or more of the following U.S. Patents: 4,326,134; 4,393,481; 4,404,475; 4,450,402; 4,486,769; 4,488,060; 4,520,461; 4,533,846;
4,599,706; 4,617,652; 4,668,932; 4,752,912; 4,829,482; 4,874,967; 4,883,976; 4,980,859; 5,012,132; 5,003,197; 5,023,694; 5,084,667; 5,153,880; 5,153,691;
5,161,137; 5,219,774; 5,270,927; 5,324,676; 5,434,396; 5,544,103; 5,587,573; 5,835,409; 5,977,585. Foreign patents and additional patents pending.
LIFE RELATED POLICY
In situations where semiconductor component failure may endanger life, system designers using this product should design the system with appropriate error detection
and correction, redundancy and back-up features to prevent such an occurrence.
Xicor’s products are not authorized for use in critical components in life support devices or systems.
1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to
perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user.
2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or effectiveness.
©Xicor, Inc. 2000 Patents Pending
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