A
PPLICATION
N
OTES
A V A I L A B L E
AN42 • AN44–48 • AN50 • AN52 • AN53 • AN71 • AN73
Terminal Voltage
±
5V,
X9C102/103/104/503 100 Taps
X9C102/103/104/503
E
2
POT
™
Nonvolatile Digital Potentiometer
FEATURES
DESCRIPTION
The Xicor X9C102/103/104/503 is a solid state nonvola-
tile potentiometer and is ideal for digitally controlled
resistance trimming.
The X9C102/103/104/503 is a resistor array composed of
99 resistive elements. Between each element and at
either end are tap points accessible to the wiper element.
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 resolution of the X9C102/103/104/503 is equal to
the maximum resistance value divided by 99. As an
example, for the X9C503 (50KΩ) each tap point repre-
sents 505Ω.
All Xicor nonvolatile memories are designed and tested
for applications requiring extended endurance and data
retention.
•
•
•
•
•
•
•
•
•
Compatible with X9102/103/104/503
Low Power CMOS
—V
CC
= 5V
—Active Current, 3mA Max
—Standby Current, 500
µ
A Max
99 Resistive Elements
—Temperature Compensated
—
±
20% End to End Resistance Range
100 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
X9C102 = 1K
Ω
X9C103 = 10K
Ω
X9C503 = 50K
Ω
X9C104 = 100K
Ω
FUNCTIONAL DIAGRAM
U/D
INC
CS
7-BIT
UP/DOWN
COUNTER
99
98
97
VH
7-BIT
NONVOLATILE
MEMORY
ONE
OF
ONE-
HUNDRED
DECODER
96
TRANSFER
GATES
2
RESISTOR
ARRAY
VCC
GND
STORE AND
RECALL
CONTROL
CIRCUITRY
1
0
VL
VW
3863 FHD F01
E
2
POT
™
is a trademark of Xicor, Inc.
©Xicor, Inc. 1994, 1995 Patents Pending
3863-2.4 9/18/96 T2/C0/D0 SH
1
Characteristics subject to change without notice
X9C102/103/104/503
PIN DESCRIPTIONS
V
H
and V
L
The high (V
H
) and low (V
L
) terminals of the X9C102/103/
104/503 are equivalent to the fixed terminals of a
mechanical potentiometer. The minimum voltage is –5V
and the maximum is +5V. 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 40Ω.
Up/Down (U/D)
The U/D input controls the direction of the wiper
movement and whether the counter is incremented or
decremented.
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 X9C102/
103/104/503 will be placed in the low power standby
mode until the device is selected once again.
DIP/SOIC
INC
U/D
VH
VSS
1
2
8
VCC
CS
VL
VW
PIN CONFIGURATION
7
X9C102/
103/104/503
6
3
4
5
3863 FHD F02.2
PIN NAMES
Symbol
V
H
V
W
V
L
V
SS
V
CC
U/D
INC
CS
NC
Description
High Terminal
Wiper Terminal
Low Terminal
Ground
Supply Voltage
Up/Down Input
Increment Input
Chip Select Input
No Connect
3863 PGM T01
2
X9C102/103/104/503
DEVICE OPERATION
There are three sections of the X9C102/103/104/503:
the input control, counter and decode section; the non-
volatile 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 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
INC,
U/D and
CS
inputs control the movement of the
wiper along the resistor array. With
CS
set LOW the
X9C102/103/104/503 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 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 X9C102/103/104/503 is powered-down, the
last counter position stored will be maintained in the
nonvolatile memory. When power is restored, the con-
tents of the memory are recalled and the counter is reset
to the value last stored.
OPERATION NOTES
The system may select the X9C102/103/104/503, move
the wiper, and deselect the device without having to
store the latest wiper, position in nonvolatile memory.
The wiper movement 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-down/up cycle recalled the
previously stored data.
This would allow 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 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
X9C102/103/104/503 and then move the wiper up and
down until the proper trim is attained.
T
IW
/R
TOTAL
The electronic switches on the X9C102/103/104/503
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 temporarily be reduced by a significant amount
if the wiper is moved several positions.
R
TOTAL
with V
CC
Removed
The end to end resistance of the array will fluctuate once
V
CC
is removed.
SYMBOL TABLE
WAVEFORM
INPUTS
Must be
steady
May change
from LOW
to HIGH
May change
from HIGH
to LOW
Don’t Care:
Changes
Allowed
N/A
OUTPUTS
Will be
steady
Will change
from LOW
to HIGH
Will change
from HIGH
to LOW
Changing:
State Not
Known
Center Line
is High
Impedance
3
X9C102/103/104/503
ABSOLUTE MAXIMUM RATINGS*
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
Voltage on V
H
and V
L
Referenced to V
SS .................................
–8V to +8V
∆V
= |V
H
–V
L
|
X9C102 ............................................................. 4V
X9C103, X9C503, and X9C104 ...................... 10V
Lead Temperature (Soldering, 10 seconds).... +300°C
Wiper Current .....................................................
±1mA
ANALOG CHARACTERISTICS
Electrical Characteristics
End-to-End Resistance Tolerance .....................
±20%
Power Rating at 25°C
X9C102 ....................................................... 16mW
X9C103, X9C503, and X9C104 .................. 10mW
Wiper Current ............................................
±1mA
Max.
Typical Wiper Resistance ......................... 40Ω at 1mA
Typical Noise .......................... < –120dB/ Hz Ref: 1V
Resolution
Resistance ............................................................. 1%
Linearity
Absolute Linearity
(1) ........................................
±1.0
Ml
(2)
Relative Linearity
(3)
.....................................
±0.2
Ml
(2)
Test Circuit #1
Temperature Coefficient
(–40°C to +85°C)
X9C102 ...................................... +600 ppm/°C Typical
X9C103, X9C503, X9C104 ........ +300 ppm/°C Typical
Ratiometric Temperature Coefficient ............
±20
ppm
Wiper Adjustability
Unlimited Wiper Adjustment (Non-Store operation)
Wiper Position Store Operations ................... 10,000
Data Changes
Physical Characteristics
Marking Includes
Manufacturer‘s Trademark
Resistance Value or Code
Date Code
Test Circuit #2
*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 specifica-
tion is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device
reliability.
VH
VH
TEST POINT
TEST POINT
VW
VL
3863 FHD F04
VW
VL
FORCE
CURRENT
3863 FHD F05
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
/99.
(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.
4
X9C102/103/104/503
RECOMMENDED OPERATING CONDITIONS
Temperature
Commercial
Industrial
Military
Min.
0°C
–40°C
–55°C
Max.
+70°C
+85°C
+125°C
3863 PGM T03.1
Supply Voltage
X9C102/103/104/503
Limits
5V
±10%
3863 PGM T04.2
D.C. OPERATING CHARACTERISTICS
(Over recommended operating conditions unless otherwise specified.)
Limits
Symbol
I
CC
I
SB
I
LI
V
IH
V
IL
R
W
V
H
V
L
C
IN(5)
Parameter
V
CC
Active Current
Standby Supply Current
CS, INC,
U/D Input
Leakage Current
CS, INC,
U/D Input
HIGH Voltage
CS, INC,
U/D Input
LOW Voltage
Wiper Resistence
VH Terminal Voltage
VL Terminal Voltage
CS, INC,
U/D Input
Capacitance
Min.
Typ.
(4)
1
200
Max.
3
500
±10
2
–1
40
–5
–5
V
CC
+ 1
0.8
100
+5
+5
10
Units
mA
µA
µA
V
V
Ω
V
V
pF
Max. Wiper Current
±1mA
Test Conditions
CS
= V
IL
, U/D = V
IL
or V
IH
and
INC
= 0.4V to 2.4V @ max. t
CYC
CS
= V
CC
– 0.3V, U/D and
INC
=
V
SS
or V
CC
– 0.3V
V
IN
= V
SS
to V
CC
V
CC
= 5V, V
IN
= V
SS
,
T
A
= 25°C, f = 1MHz
3863 PGM T05.3
STANDARD PARTS
Part Number
X9C102
X9C103
X9C503
X9C104
Maximum Resistance
1KΩ
10KΩ
50KΩ
100KΩ
Wiper Increments
10.1Ω
101Ω
505Ω
1010Ω
Minimum Resistance
40Ω
40Ω
40Ω
40Ω
3863 PGM T08.1
Notes:
(4) Typical values are for T
A
= 25°C and nominal supply voltage.
(5) This parameter is periodically sampled and not 100% tested.
5
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