®
X9250
Low Noise/Low Power/SPI Bus/256 Taps
Data Sheet
August 29, 2006
FN8165.3
Quad Digitally Controlled Potentiometers
(XDCP™)
FEATURES
•
•
•
•
•
•
•
•
Four potentiometers in one package
256 resistor taps/pot - 0.4% resolution
SPI serial interface
Wiper resistance, 40Ω typical @ V
CC
= 5V
Four nonvolatile data registers for each pot
Nonvolatile storage of wiper position
Standby current < 5µA max (total package)
Power supplies
—V
CC
= 2.7V to 5.5V
—V+ = 2.7V to 5.5V
—V– = -2.7V to -5.5V
100kΩ, 50kΩ total pot resistance
High reliability
—Endurance – 100,000 data changes per bit per
register
—Register data retention - 100 years
24 Ld SOIC, 24 Ld TSSOP
Dual supply version of X9251
Pb-free plus anneal available (RoHS compliant)
DESCRIPTION
The X9250 integrates 4 digitally controlled
potentiometers (XDCP) on a monolithic CMOS
integrated circuit.
The digitally controlled potentiometer is implemented
using 255 resistive elements in a series array.
Between each element are tap points connected to the
wiper terminal through switches. The position of the
wiper on the array is controlled by the user through the
SPI bus interface. Each potentiometer has associated
with it a volatile Wiper Counter Register (WCR) and 4
nonvolatile Data Registers (DR0:DR3) that can be
directly written to and read by the user. The contents
of the WCR controls the position of the wiper on the
resistor array though the switches. Power up recalls
the contents of DR0 to the WCR.
The XDCP can be used as a three-terminal
potentiometer or as a two-terminal variable resistor in
a wide variety of applications including control,
parameter adjustments, and signal processing.
•
•
•
•
•
BLOCK DIAGRAM
V
CC
V
SS
V+
V-
R
0
R
1
Wiper
Counter
Register
(WCR)
Pot 0
V
H0
/R
H0
R
0
R
1
Wiper
Counter
Register
(WCR)
V
H2
/R
H2
HOLD
CS
SCK
SO
SI
A0
A1
WP
R
2
R
3
V
L0
/R
L0
V
W0
/R
W0
R
2
R
3
Resistor
Array
Pot 2
V
L2
/R
L2
V
W2
/R
W2
Interface
and
Control
Circuitry
Data
8
V
W1
/R
W1
R
0
R
1
Wiper
Counter
Register
(WCR)
V
H1
/R
H1
R
0
R
1
Wiper
Counter
Register
(WCR)
V
W3
/R
W3
V
H3
/R
H3
R
2
R
3
Resistor
Array
Pot1
V
L1
/R
L1
R
2
R
3
Resistor
Array
Pot 3
V
L3
/R
H3
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
|
Intersil (and design) is a registered trademark of Intersil Americas Inc.
XDCP is a trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005, 2006. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
X9250
Ordering Information
PART NUMBER
X9250TS24I
X9250TS24IZ (Note)
X9250TV24I
X9250TV24IZ (Note)
X9250US24
X9250US24Z (Note)
X9250US24I
X9250US24IZ (Note)
X9250UV24I
X9250UV24IZ (Note)
X9250TS24-2.7
PART
MARKING
X9250TS I
X9250TS ZI
X9250TV I
X9250TV ZI
X9250US
X9250US Z
X9250US I
X9250US ZI
X9250UV I
X9250UV ZI
X9250TS F
-2.7 to 5.5
100
50
V
CC
LIMITS (V)
5 ±10%
POTENTIOMETER
ORGANIZATION (kΩ)
100
TEMP. RANGE
(°C)
-40 to +85
-40 to +85
-40 to +85
-40 to +85
0 to +70
0 to +70
-40 to +85
-40 to +85
-40 to +85
-40 to +85
0 to +70
0 to +70
-40 to +85
-40 to +85
-40 to +85
-40 to +85
50
0 to +70
0 to +70
-40 to +85
-40 to +85
0 to +70
0 to +70
-40 to +85
-40 to +85
PACKAGE
24 Ld SOIC (300 mil)
24 Ld SOIC (300 mil)
(Pb-free)
24 Ld TSSOP
(4.4mm)
24 Ld TSSOP
(4.4mm) (Pb-free)
24 Ld SOIC (300 mil)
24 Ld SOIC (300 mil)
(Pb-free)
24 Ld SOIC (300 mil)
24 Ld SOIC (300 mil)
(Pb-free)
24 Ld TSSOP
(4.4mm)
24 Ld TSSOP
(4.4mm) (Pb-free)
24 Ld SOIC (300 mil)
24 Ld SOIC (300 mil)
(Pb-free)
24 Ld SOIC (300 mil)
24 Ld SOIC (300 mil)
(Pb-free)
24 Ld TSSOP
(4.4mm)
24 Ld TSSOP
(4.4mm) (Pb-free)
24 Ld SOIC (300 mil)
24 Ld SOIC (300 mil)
(Pb-free)
24 Ld SOIC (300 mil)
24 Ld SOIC (300 mil)
(Pb-free)
24 Ld TSSOP
(4.4mm)
24 Ld TSSOP
(4.4mm) (Pb-free)
24 Ld TSSOP
(4.4mm)
24 Ld TSSOP
(4.4mm) (Pb-free)
PKG. DWG. #
M24.3
M24.3
MDP0044
MDP0044
M24.3
M24.3
M24.3
M24.3
MDP0044
MDP0044
M24.3
M24.3
M24.3
M24.3
MDP0044
MDP0044
M24.3
M24.3
M24.3
M24.3
MDP0044
MDP0044
MDP0044
MDP0044
X9250TS24Z-2.7 (Note) X9250TS ZF
X9250TS24I-2.7*
X9250TS24IZ-2.7*
(Note)
X9250TV24I-2.7
X9250TS G
X9250TS ZG
X9250TV G
X9250TV24IZ-2.7 (Note) X9250TV ZG
X9250US24-2.7*
X9250US F
X9250US24Z-2.7* (Note) X9250US ZF
X9250US24I-2.7
X9250US G
X9250US24IZ-2.7 (Note) X9250US ZG
X9250UV24-2.7
X9250UV F
X9250UV24Z-2.7 (Note) X9250UV ZF
X9250UV24I-2.7
X9250UV G
X9250UV24IZ-2.7 (Note) X9250UV ZG
*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.
2
FN8165.3
August 29, 2006
X9250
PIN DESCRIPTIONS
Serial Output (SO)
SO is a serial data output pin. During a read cycle,
data is shifted out on this pin. Data is clocked out by
the falling edge of the serial clock.
Serial Input
SI is the serial data input pin. All opcodes, byte
addresses and data to be written to the pots and pot
registers are input on this pin. Data is latched by the
rising edge of the serial clock.
Serial Clock (SCK)
The SCK input is used to clock data into and out of the
X9250.
Chip Select (CS)
When CS is HIGH, the X9250 is deselected and the
SO pin is at high impedance, and (unless an internal
write cycle is underway) the device will be in the
standby state. CS LOW enables the X9250, placing it
in the active power mode. It should be noted that after
a power-up, a HIGH to LOW transition on CS is
required prior to the start of any operation.
Hold (HOLD)
HOLD is used in conjunction with the CS pin to select
the device. Once the part is selected and a serial
sequence is underway, HOLD may be used to pause
the serial communication with the controller without
resetting the serial sequence. To pause, HOLD must
be brought LOW while SCK is LOW. To resume
communication, HOLD is brought HIGH, again while
SCK is LOW. If the pause feature is not used, HOLD
should be held HIGH at all times.
Device Address (A
0
-
A
1
)
The address inputs are used to set the least significant
2 bits of the 8-bit slave address. A match in the slave
address serial data stream must be made with the
address input in order to initiate communication with
the X9250. A maximum of 4 devices may occupy the
SPI serial bus.
Potentiometer Pins
V
H
/R
H
(V
H0
/R
H0
- V
H3
/R
H3
), V
L
/R
L
(V
L0
/R
L0
-
V
L3
/R
L3
)
The R
H
and R
L
pins are equivalent to the terminal
connections on a mechanical potentiometer.
S0
A0
V
W3
/R
W3
V
H3
/R
H3
V
L3
/R
L3
V+
V
CC
V
L0
/R
L0
V
H0
/R
H0
V
W0
/R
W0
CS
WP
V
W
/R
W
(V
W0
/R
W0 -
V
W3
/R
W3
)
The wiper pins are equivalent to the wiper terminal of a
mechanical potentiometer.
Hardware Write Protect Input (WP)
The WP pin when LOW prevents nonvolatile writes to
the Data Registers.
Analog Supplies (V+, V-)
The analog supplies V+, V- are the supply voltages for
the XDCP analog section.
PIN CONFIGURATION
SOIC/TSSOP
1
2
3
4
5
6
7
8
9
10
11
12
X9250
24
23
22
21
20
19
18
17
16
15
14
13
HOLD
SCK
V
L2
/R
L2
V
H2
/R
L2
V
W2
/R
W2
V–
V
SS
V
W1
/R
W1
V
H1
/R
H1
V
L1
/R
L1
A1
SI
PIN NAMES
Symbol
SCK
SI, SO
A
0
-A
1
V
H0
/R
H0–
V
H3
/R
H3
,
V
L0
/R
L0–
V
L3
/R
L3
V
W0
/R
W0–
V
W3
/R
W3
WP
V+,V-
V
CC
V
SS
NC
Description
Serial Clock
Serial Data
Device Address
Potentiometer Pins
(terminal equivalent)
Potentiometer Pins
(wiper equivalent)
Hardware Write Protection
Analog Supplies
System Supply Voltage
System Ground
No Connection
3
FN8165.3
August 29, 2006
X9250
DEVICE DESCRIPTION
Serial Interface
The X9250 supports the SPI interface hardware
conventions. The device is accessed via the SI input
with data clocked in on the rising SCK. CS must be
LOW and the HOLD and WP pins must be HIGH
during the entire operation.
The SO and SI pins can be connected together, since
they have three state outputs. This can help to reduce
system pin count.
Array Description
The X9250 is comprised of four resistor arrays. Each
array contains 255 discrete resistive segments that
are connected in series. The physical ends of each
array are equivalent to the fixed terminals of a
mechanical potentiometer (V
H
/R
H
and V
L
/R
L
inputs).
At both ends of each array and between each resistor
segment is a CMOS switch connected to the wiper
(V
W
/R
W
) output. Within each individual array only one
switch may be turned on at a time.
These switches are controlled by a Wiper Counter
Register (WCR). The 8 bits of the WCR are decoded
to select, and enable, one of 256 switches.
Wiper Counter Register (WCR)
The X9250 contains four Wiper Counter Registers,
one for each XDCP potentiometer. The WCR is
equivalent to a serial-in, parallel-out register/counter
with its outputs decoded to select one of 256 switches
along its resistor array. The contents of the WCR can
be altered in four ways: it may be written directly by
the host via the write Wiper Counter Register
instruction (serial load); it may be written indirectly by
transferring the contents of one of four associated
Data Registers via the XFR Data Register or Global
XFR Data Register instructions (parallel load); it can
be modified one step at a time by the
increment/decrement instruction. Finally, it is loaded
with the contents of its Data Register zero (DR0) upon
power-up.
The Wiper Counter Register is a volatile register; that
is, its contents are lost when the X9250 is powered-
down. Although the register is automatically loaded
with the value in R0 upon power-up, this may be
different from the value present at power-down.
Data Registers
Each potentiometer has four 8-bit nonvolatile Data
Registers. These can be read or written directly by the
host. Data can also be transferred between any of the
four Data Registers and the associated Wiper Counter
Register. All operations changing data in one of the
Data Registers is a nonvolatile operation and will take
a maximum of 10ms.
If the application does not require storage of multiple
settings for the potentiometer, the Data Registers can
be used as regular memory locations for system
parameters or user preference data.
Data Register Detail
(MSB)
D7
NV
D6
NV
D5
NV
D4
NV
D3
NV
D2
NV
D1
NV
(LSB)
D0
NV
4
FN8165.3
August 29, 2006
X9250
Figure 1. Detailed Potentiometer Block Diagram
(One of Four Arrays)
Serial Data Path
From Interface
Circuitry
Register 0
8
Register 1
8
Parallel
Bus
Input
Wiper
Counter
Register
(WCR)
Serial
Bus
Input
C
o
u
n
t
e
r
D
e
c
o
d
e
V
H
/R
H
Register 2
Register 3
If WCR = 00[H] then V
W
/R
W
= V
L
/R
L
If WCR = FF[H] then V
W
/R
W
= V
H
/R
H
UP/DN
Modified SCK
Inc/Dec
Logic
UP/DN
CLK
V
L
/R
L
V
W
/R
W
Write in Process
The contents of the Data Registers are saved to
nonvolatile memory when the CS pin goes from LOW
to HIGH after a complete write sequence is received
by the device. The progress of this internal write
operation can be monitored by a write in process bit
(WIP). The WIP bit is read with a read status
command.
INSTRUCTIONS
Identification (ID) Byte
The first byte sent to the X9250 from the host,
following a CS going HIGH to LOW, is called the
Identification byte. The most significant four bits of the
slave address are a device type identifier, for the
X9250 this is fixed as 0101[B] (refer to Figure 2).
The two least significant bits in the ID byte select one
of four devices on the bus. The physical device
address is defined by the state of the A
0
- A
1
input
pins. The X9250 compares the serial data stream with
the address input state; a successful compare of both
address bits is required for the X9250 to successfully
continue the command sequence. The A
0
- A
1
inputs
can be actively driven by CMOS input signals or tied to
V
CC
or V
SS
.
The remaining two bits in the slave byte must be set to 0.
Figure 2. Identification Byte Format
Device Type
Identifier
0
1
0
1
0
0
A1
A0
Device Address
Instruction Byte
The next byte sent to the X9250 contains the
instruction and register pointer information. The four
most significant bits are the instruction. The next four
bits point to one of the four pots and, when applicable,
they point to one of four associated registers. The
format is shown below in Figure 3.
Figure 3. Instruction Byte Format
Register
Select
I3
I2
I1
I0
R1
R0
P1
P0
Instructions
Pot Select
5
FN8165.3
August 29, 2006
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