1
FN8181.1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or1-888-468-3774
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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.
X93155
Digitally Controlled Potentiometer
(XDCPTM)
The Intersil X93155 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 31 resistive elements and a wiper switching
network. 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 is connected as a two-terminal variable resistor
and can be used in a wide variety of applications including:
- Bias and Gain Control
- LCD Contrast Adjustment
Features
Solid-state potentiometer
Up/Down interface
32 wiper tap points per potentiometer
- Wiper position stored in nonvolatile memory and
recalled on power-up
31 resistive elements per potentiometer
- Temperature compensated
- Maximum resistance tolerance 25%
- Terminal voltage, 0 to V
CC
Low power CMOS
- V
CC
= 5V10%
- Active current, 200A typ.
- Standby current, 2.0A max
High reliability
- Endurance 200,000 data changes per bit
- Register data retention, 100 years
R
TOTAL
value = 50k
Packages
- 8 Ld MSOP
Pb-free plus anneal available (RoHS compliant)
Pinout
X93155
(8 LD MSOP)
TOP VIEW
1
NC can be left unconnected, or connected to any voltage between V
SS
and V
CC.
Ordering Information
PART
NUMBER
PART
MARKING
R
TOTAL
(k
)
TEMP
RANGE (C) PACKAGE
X93155UM8I*
AGM
50
-40 to 85
8 Ld MSOP
X93155UM8IZ*
(Note)
DCH
50
-40 to 85
8 Ld MSOP
(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.
V
CC
CS
INC
U/D
R
H
V
SS
1
2
3
4
8
7
6
5
R
L
NC
1
Data Sheet
September 26, 2005
2
FN8181.1
September 26, 2005
Block Diagram
5-Bit
Up/Down
Counter
5-Bit
Nonvolatile
Memory
Store and
Recall
Control
Circuitry
One
of
Decoder
Resistor
Array
R
H
U/D
INC
CS
Transfer
Gates
Thirty
V
CC
V
SS
R
L
Control
and
Memory
Up/Down
(U/D)
Increment
(INC)
Device Select
(CS)
V
CC
(Supply Voltage)
V
SS
(Ground)
R
H
General
Detailed
0
1
2
28
29
30
31
Two
R
L
30k
Pin Descriptions
MSOP
SYMBOL
BRIEF DESCRIPTION
1
INC
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.
2
U/D
Up/Down (U/D). The U/D input controls the direction of the wiper movement and whether the counter is incremented or
decremented.
3
R
H
R
H
. The R
H
and R
L
pins of the X93155 are equivalent to the end terminals of a variable resistor.
4
V
SS
Ground.
5
NC
No Connection. (or can be connected to any voltage between V
SS
and V
CC
.)
6
R
L
R
L
. The R
H
and R
L
pins of the X93155 are equivalent to the end terminals of a variable resistor.
7
CS
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 X93155
will be placed in the low power standby mode until the device is selected once again.
8
V
CC
Supply Voltage.
X93155
3
FN8181.1
September 26, 2005
Absolute Maximum Ratings
Recommended Operating Conditions
Temperature under bias . . . . . . . . . . . . . . . . . . . . . .-65
C to +135C
Storage temperature . . . . . . . . . . . . . . . . . . . . . . . .-65C to +150C
Voltage on CS, INC, U/D, R
H
, R
L
and V
CC
with respect to V
SS
. . . . . . . . . . . . . . . . . . . . . . . . . . -1V to +6.5V
Lead temperature (soldering 10 seconds) . . . . . . . . . . . . . . . . 300C
Maximum reflow temperature (40 seconds). . . . . . . . . . . . . . . 240C
Maximum resistor current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2mA
Temperature Range
Industrial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40C to +85C
Supply Voltage
V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5V 10%
(7)
CAUTION: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only; 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. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Potentiometer Specifications
Over recommended operating conditions unless otherwise stated.
SYMBOL
PARAMETER
TEST CONDITIONS/NOTES
MIN
TYP
MAX
UNIT
R
TOT
End to end resistance
37.5
50
62.5
k
V
R
R
H
, R
L
terminal voltages
0
V
CC
V
Power rating
R
TOTAL
=50k
1
mW
(6)
Noise
Ref: 1kHz
-120
dBV
(6)
I
R
Potentiometer Current
(5)
0.6
mA
Resolution
3
%
Absolute linearity
(1)
R
H(n)(actual)
-R
H(n)(expected)
1
MI
(3)
Relative linearity
(2)
R
H(n+1)
-[R
H(n)+MI
]
0.5
MI
(3)
R
TOTAL
temperature coefficient
(6)
35
ppm/C
C
H
/C
L
/C
W
Potentiometer capacitances
See circuit #2
10/10/25
pF
(6)
Notes: (1) Absolute linearity is utilized to determine actual wiper resistance versus expected resistance = (R
H(n)
(actual)-R
H(n)
(expected)) = 1
Ml Maximum. n = 1 .. 29 only
(2) Relative linearity is a measure of the error in step size between taps = R
H(n+1)
--[R
H(n)
+ Ml] = 0.5 Ml, n = 1 .. 29 only.
(3) 1 Ml = Minimum Increment = R
TOT
/31.
(4) Typical values are for T
A
= 25C and nominal supply voltage.
(5) This parameter is periodically sampled and not 100% tested
(6) This parameter is not 100% tested.
(7) When performing multiple write operations, V
CC
must not decrease by more than 150mV from its initial value.
DC Electrical Specifications
Over recommended operating conditions unless otherwise specified.
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
TYP (4)
MAX
UNIT
I
CC1
VCC active current (Increment)
CS = V
IL
, U/D = V
IL
or V
IH
and
INC = 0.4V @ max. t
CYC
200
300
A
I
CC2
VCC active current (Store)
(EEPROM Store)
CS = V
IH
, U/D = V
IL
or V
IH
and
INC = V
IH
@ max. t
WR
1400
A
I
SB
Standby supply current
CS = V
CC
- 0.3V, U/D and INC = V
SS
or V
CC
- 0.3V
2.0
A
I
LI
CS
V
CS
= V
CC
1
A
I
LI
CS
V
CC
= 5V, CS = 0
120
200
250
A
I
LI
INC, U/D input leakage current
V
IN
= V
SS
to V
CC
1
A
V
IH
CS, INC, U/D input HIGH voltage
V
CC
x 0.7
V
CC
+ 0.5
V
V
IL
CS, INC, U/D input LOW voltage
-0.5
V
CC
x 0.1
V
C
IN
(5)(7)
CS, INC, U/D input capacitance
V
CC
= 5V, V
IN
= V
SS
, T
A
= 25C,
f = 1MHz
10
pF
X93155
4
FN8181.1
September 26, 2005
Test Circuit #1
Circuit #2 SPICE Macro Model
Power Up and Down Requirements
There are no restrictions on the power-up or power-down
conditions of V
CC
and the voltages applied to the
potentiometer pins provided that V
CC
is always more
positive than or equal to V
H
and V
L
, i.e., V
CC
V
H,
V
L
. The
V
CC
ramp rate spec is always in effect.
Endurance and Data Retention
PARAMETER
MIN
UNIT
Minimum endurance
200,000
Data changes per bit
Data retention
100
Years
V
L
Test Point
V
H
/R
H
A.C. Conditions of Test
Input pulse levels
0V to 5V
Input rise and fall times
10ns
Input reference levels
1.5V
C
H
C
L
10pF
10pF
R
H
R
TOTAL
C
W
25pF
R
L
AC Electrical Specifications
Over recommended operating conditions unless otherwise specified.
SYMBOL
PARAMETER
MIN
TYP (6)
MAX
UNIT
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
100
ns
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)
250
ns
t
CPH
CS Deselect time (STORE)
10
ms
t
CYC
INC cycle time
2
s
t
R
, t
F
(6)
INC input rise and fall time
500
s
t
R
V
CC
(6)
VCC power-up rate
1
10,000
V/ms
t
WR
Store cycle
5
10
ms
X93155
5
FN8181.1
September 26, 2005
A.C. Timing
Pin Descriptions
R
H
and R
L
The R
H
and R
L
pins of the X93155 are equivalent to the end
terminals of a variable resistor. The minimum voltage is V
SS
and the maximum is V
CC
. The terminology of R
H
and R
L
references the relative position of the terminal in relation to
wiper movement direction selected by the U/D input.
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 X93155 will be placed in
the low power standby mode until the device is selected
once again.
Principles of Operation
There are three sections of the X93155: 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 transfers the connection at that
point to the wiper. The wiper is connected to the R
L
terminal,
forming a variable resistor from R
H
to R
L
.
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.
If the wiper is moved several positions, multiple taps are
connected to the wiper for up to 10s. The 2-terminal
resistance value for the device can temporarily change by a
significant amount if the wiper is moved several positions.
When the device is powered-down, the last wiper position
stored will be maintained in the nonvolatile memory. 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 five
bit counter. The output of this counter is decoded to select
one of thirty two wiper positions along the resistive array.
The value of the counter is stored in nonvolatile memory
whenever CS transitions HIGH while the INC input is also
HIGH. In order to avoid an accidental store during power-up,
CS must go HIGH with V
CC
during initial power-up. When
left open, the CS pin is internally pulled up to V
CC
by an
internal 30k
resistor.
The system may select the X93155, move the wiper and
deselect the device without having to store the latest 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 position will be maintained until
CS
INC
U/D
t
CI
t
IL
t
IH
t
CYC
t
ID
t
DI
t
IC
t
CPH
t
F
t
R
10%
90%
90%
(Store)
X93155
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