Document Outline
- Table of Contents
- Product Selection
- Data Sheet Alpha
- Ap Note Alpha
6732-2.0 5/30/97 T1/C0/D0 SH
1
Characteristics subject to change without notice
A
PPLICATION
N
OTE
A V A I L A B L E
Low Noise, Low Power, 32 Taps
X9315
E
2
POT
TM
Nonvolatile Digital Potentiometer
FEATURES
Low Power CMOS
--V
CC
= 2.7V to 5.5V, Single Supply
--Active Current, 50
A (Increment) max
--Active Current, 400
A (Store) Max
--Standby Current, 1
A Max
Low Noise
31 Resistive Elements
--Temperature Compensated
--
20% End to End Resistance Range
--V
SS
to V
CC
Range
32 Wiper Tap Points
--Wiper Positioned via Three-Wire Interface
--Similar to TTL Up/Down Counter
--Wiper Position Stored in Nonvolatile Memory
and Recalled on Power-Up
100 Year Wiper Position Data Retention
X9315Z = 1K
X9315W = 10K
Packages
--8-Lead SOIC
--8-Lead MSOP
--8-Pin DIP
DESCRIPTION
The Xicor X9315 is a solid state "micropower" nonvol-
atile potentiometer and is ideal for digitally controlled
resistance trimming.
The X9315 is a resistor array composed of 31 resistive
elements. Between each element and at either end are
tap points accessible to the wiper element. The posi-
tion 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 sub-
sequent power-up operation.
The resolution of the X9315 is equal to the maximum
resistance value divided by 31. As an example, for the
X9315W (10K
) each tap point represents 323
.
All Xicor nonvolatile digital potentiometers are de-
signed and tested for applications requiring extended
endurance and data retention.
FUNCTIONAL DIAGRAM
5-BIT
UP/DOWN
COUNTER
5-BIT
NONVOLATILE
MEMORY
STORE AND
RECALL
CONTROL
CIRCUITRY
ONE
OF
THIRTY-
TWO
WIPER
POSITION
DECODER
RESISTOR
ARRAY
VL
VW
VH
U/D
INC
CS
CMOS SWITCH
6732 FM1
E
2
POTTM is a trademark of Xicor, Inc.
AN104
X9315
2
PIN DESCRIPTIONS
V
H
and V
L
The high (V
H
) and low (V
L
) terminals of the X9315 are
equivalent to the fixed terminals of a mechanical potenti-
ometer. The minimum voltage is V
SS
and the maximum is
V
CC
. It should be noted that the terminology of V
L
and 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.
V
W
V
w
is the wiper terminal, 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
400
.
Up/Down (U/D)
The U/D input controls the direction of the wiper move-
ment and whether the counter is incremented or decre-
mented.
Increment (INC)
The INC input is negative-edge triggered. Toggling INC
will move the wiper and either increment or decrement
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 X9315
will be placed in the low power standby mode until the
device is selected once again.
PIN CONFIGURATION
6732 FM2
PIN NAMES
6732 FM T01
Symbol
Description
V
H
High Terminal
V
W
Wiper Terminal
V
L
Low Terminal
V
SS
Ground
V
CC
Supply Voltage
U/D
Up/Down Input
INC
Increment Input
CS
Chip Select Input
V
CC
CS
V
L
V
W
INC
U/D
V
H
V
SS
1
2
3
4
8
7
6
5
X9315
DIP/SOIC/MSOP
X9315
3
DEVICE OPERATION
There are three sections of the X9315: the input control,
counter and decode section; the nonvolatile memory;
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 comprised of 31 individual resistors
connected in series. At either end of the array and
between each resistor is an electronic switch that trans-
fers the potential at that point to the wiper.
The INC, U/D and CS inputs control the movement of the
wiper along the resistor array. With CS set LOW the
X9315 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 thirty two wiper positions
along the resistive array.
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 value of the counter is stored in nonvolatile memory
whenever CS transistions HIGH while the INC input is
also HIGH.
When the X9315 is powered-down, the last counter posi-
tion stored will be maintained in the nonvolatile memory.
When power is restored, the contents of the memory are
recalled and the counter is reset to the value last stored.
Operation Notes
The system may select the X9315, move the wiper and
deselect the device without having to store the latest
wiper position in nonvolatile memory. The wiper move-
ment is performed as described above; once the new
position is reached, the system would the keep INC LOW
while taking CS HIGH. The new wiper position would be
maintained until changed by the system or until a power-
up/down cycle recalled the previously stored data.
This would allow the system to always power-up to a pre-
set value stored in nonvolatile memory; then during sys-
tem operation minor adjustments could be made. The
adjustments might be based on user preference, system
parameter changes due to temperature drift, etc...
The state of U/D may be changed while CS remains
LOW. This allows the host system to enable the X9315
and then move the wiper up and down until the proper
trim is attained.
SYMBOL TABLE
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
6732 FM 3
X9315
4
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
Wiper Current ...........................................................
1mA
*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 specification is
not implied.
ANALOG CHARACTERISTICS
Electrical Characteristics
Temperature under Bias.........................65
C to +135
C
End-to-End Resistance Tolerance ..........................
20%
Power Rating at 25
C ..............................................10mW
Wiper Current .................................................
1mA Max.
Typical Wiper Resistance ............................ 400
at 1mA
Typical Noise.................................. < 140dB
Hz Ref: 1V
Resolution
Resistance ................................................................... 3%
Linearity
Absolute Linearity
(1)
...........................................
1.0 Ml
(2)
Relative Linearity
(3)
...........................................
0.2 Ml
(2)
Temperature Coefficient
(40
C to +85
C) ..............................+300 ppm/
C Typical
Ratiometric Temperature Coefficient ..................
20 ppm
Wiper Adjustability
Unlimited Wiper Adjustment (Non-Store operation)
Wiper Position Store Operations .......................... 100,000
Physical Characteristics
Marking Includes
Manufacturer's Trademark
Resistance Value or Code
Date Code
Test Circuit #2
6732 FM 5
FORCE
CURRENT
V
L
VW
V
H
TEST POINT
Test Circuit #1
6732 FM 4
TEST POINT
V
W
V
H
V
L
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) 1 Ml = Minimum Increment = R
TOT
/31.
(3) Relative Linearity is a measure of the error in step size between taps = V
W(n+1)
[V
w(n)
+ Ml] = +0.2 Ml.
X9315
5
RECOMMENDED OPERATING CONDITIONS
6732 PGM T02
6732 PGM T03
Temperature
Min.
Max.
Commercial
0
C
+70
C
Industrial
40
C
+85
C
Supply Voltage
Limits
X9315
5V
10%
X9315-2.7
2.7V to 5.5V
D.C. OPERATING CHARACTERISTICS
(Over recommended operating conditions unless otherwise specified.)
6732 PGM T04
STANDARD PARTS
6732 PGM T05
Notes: (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
Units
Test Conditions
Min.
Typ.
(4)
Max.
I
CC1
V
CC
Active Current
(Increment)
50
A
CS = V
IL
, U/D = V
IL
or V
IH
and
INC = 0.4V/2.4V @ max. t
CYC
I
CC2
V
CC
Active Current
(Store)
400
A
CS = V
IH
, U/D = V
IL
or V
IH
and INC = V
IH
I
SB
Standby Supply Current
1
A
CS = V
CC
0.3V, U/D and
INC = V
SS
or V
CC
0.3V
I
LI
CS, INC, U/D Input
10
A
V
IN
= V
SS
to V
CC
Leakage Current
V
IH
CS, INC, U/D Input
2
V
CC
+ 1
V
HIGH Voltage
V
IL
CS, INC, U/D Input
0.5
0.8
V
LOW Voltage
R
W
Wiper Resistence
400
1000
Max. Wiper Current
1mA
V
VH
VH Terminal Voltage
V
SS
V
CC
V
V
VL
VL Terminal Voltage
V
SS
V
CC
V
C
IN
(5)
CS, INC, U/D Input
10
pF
V
CC
= 5V, V
IN
= V
SS
,
Capacitance
T
A
= 25
C, f = 1MHz
Part Number
Maximum Resistance
Wiper Increments
Minimum Resistance
X9315Z
1K
32.3
100
X9315W
10K
323
100
X9315
6
A.C. CONDITIONS OF TEST
6732 PGM T06
MODE SELECTION
6732 PGM T07
Input Pulse Levels
0V to 3V
Input Rise and Fall Times
10ns
Input Reference Levels
1.5V
CS
INC
U/D
Mode
L
H
Wiper Up
L
L
Wiper Down
H
X
Store Wiper Position
H
X
X
Standby
L
X
No Store, Return to Standby
A.C. OPERATING CHARACTERISTICS (Over recommended operating conditions unless otherwise specified)
6732 PGM T08
A.C. TIMING
Notes: (6) Typical values are for T
A
= 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 V
W
output due to a change in the wiper position.
Limits
Symbol
Parameter
Min.
Typ.
(6)
Max.
Units
t
Cl
CS to INC Setup
100
ns
t
lD
INC HIGH to U/D Change
100
ns
t
DI
U/D to INC Setup
2.9
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
CPH
CS Deselect Time (NO STORE)
100
ns
t
IW
INC to Vw Change
1
5
s
t
CYC
INC Cycle Time
4
s
t
R,
t
F
(7)
INC Input Rise and Fall Time
500
s
t
PU
(7)
Power up to Wiper Stable
5
s
t
R
V
CC
(7)
V
CC
Power-up Rate
0.2
50
mV/
s
t
WR
Store Cycle
5
10
ms
6732 FM 06
CS
INC
U/D
VW
t
CI
t
IL
t
IH
t
CYC
t
ID
t
DI
t
IW
MI
(8)
t
IC
t
CPH
t
F
t
R
10%
90%
90%
X9315
7
TYPICAL NOISE
TYPICAL RTOTAL vs. TEMPERATURE
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
-150
0
10
20
30
40
50
60
70
80
90
100
Frequenc y (KHz)
Noise (dB)
110
120
130
140
150
160
170
180
190
200
10000
9800
9600
9400
9200
9000
8800
8600
8400
8200
8000
Rtotal
-55
-45
-35
-25
-15
-5
5
15
25
35
45
55
65
75
Temperature
85
95
105
115 125 C
X9315
8
TYPICAL TOTAL RESISTANCE TEMPERATURE COEFFICIENT
TYPICAL WIPER RESISTANCE
-55
-350
-300
-250
-200
-150
-100
-50
0
-45
-35
-25
-15
-5
5
15
25
35
Temperature
PPM
45
55
65
75
85
95
105
115
125
C
0
0
100
200
300
400
Rw (Ohms)
500
600
700
800
2
4
6
8
10
12
14
16
Tap
18
20
22
24
26
28
30
32
X9315
9
TYPICAL ABSOLUTE % ERROR PER TAP POSITION
TYPICAL RELATIVE % ERROR PER TAP POSITION
40.0%
30.0%
20.0%
10.0%
0.0%
-10.0%
-20.0%
-30.0%
-40.0%
0
3
6
9
12
15
Tap
Absolute % Error
18
21
24
27
30
20.0%
15.0%
10.0%
5.0%
0.0%
-5.0%
-10.0%
-15.0%
-20.0%
0
3
6
9
12
15
Tap
Relative % Error
18
21
24
27
30
X9315
10
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)
REF.
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
8-LEAD MINIATURE SMALL OUTLINE GULL WING PACKAGE TYPE M
NOTE:
1. ALL DIMENSIONS IN INCHES AND (MILLIMETERS)
3003 ILL 01
X9315
11
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
PLANE
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
0.015 (0.38)
MAX.
0.325 (8.25)
0.300 (7.62)
X9315
12
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 PLACES
FOOTPRINT
X9315
13
ORDERING INFORMATION
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,
licenses are implied.
U.S. PATENTS
Xicor products are covered by one or more of the following U.S. Patents: 4,263,664; 4,274,012; 4,300,212; 4,314,265; 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. 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 occurence.
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.
V
CC
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
M = 8-Lead MSOP
P = 8-Lead Plastic DIP
S = 8-Lead SOIC
End to End Resistance
Z = 1K
W = 10K
X9315X
X
X
X
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