View X9318_192854.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Digitally Controlled Potentiometer (XDCPTM)
FEATURES * * * * Solid-state potentiometer 3-wire serial interface Terminal voltage, 0 to +8V 100 wiper tap points --Wiper position stored in nonvolatile memory and recalled on power-up 99 resistive elements --Temperature compensated --End to end resistance range 20% Low power CMOS --VCC = 5V --Active current, 3mA max. --Standby current, 1mA max. High reliability --Endurance, 100,000 data changes per bit --Register data retention, 100 years RTOTAL value = 10K Packages --8-lead SOIC and DIP DESCRIPTION
X9318
The Xicor X9318 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 99 resistive elements and a wiper switching network. Between each element and at either end are tap points accessible to the wiper terminal. 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 can be used as a three-terminal potentiometer for voltage control or as a two-terminal variable resistor for current control in a wide variety of applications.
*
*
*
* *
APPLICATIONS * * * * * LCD bias control DC bias adjustment Gain and offset trim Laser diode bias control Voltage regulator output control
BLOCK DIAGRAM
U/D INC CS Up/Down Counter 99 98 97 7-Bit Nonvolatile Memory 96 One of One Hundred Decoder 2 VSS (Ground) General VCC VSS Store and Recall Control Circuitry 1 0 RL RW Detailed
XDCP is a trademark of Xicor, Inc.
RH
VCC (Supply Voltage)
Up/Down (U/D) Increment (INC) Device Select (CS) Control and Memory
RH RW
Wiper Switches
Resistor Array
RL
REV 1.9 4/3/03
www.xicor.com
1 of 10
X9318
PIN CONFIGURATION
DIP/SOIC INC U/D RH VSS 1 2 3 4 X9318 8 7 6 5 VCC CS RL RW
X9318X
X
X Operating Temperature Range Blank = Commercial = 0C to +70C I = Industrial = -40C to +85C Package P = 8-Lead Plastic DIP S = 8-Lead SOIC End to End Resistance W= 10K
ORDERING INFO Ordering Number
X9318WS8 X9318WS8I X9318WP8 X9318WP8I
RTOTAL
10Kohm 10Kohm 10Kohm 10Kohm 8-lead SOIC 8-lead SOIC 8-lead Plastic DIP 8-lead Plastic DIP
Package
Operating Temperature Range
0C to 70C -40C to +85C 0C to 70C -40C to +85C
PIN DESCRIPTIONS DIP/ SOIC
1 2 3 4 5 6 7 8
Symbol
INC U/D RH VSS RW RL CS VCC
Brief Description
Increment. Toggling INC while CS is low moves the wiper either up or down. Up/Down. The U/D input controls the direction of the wiper movement. The high terminal is equivalent to one of the fixed terminals of a mechanical potentiometer. Ground. The wiper terminal is equivalent to the movable terminal of a mechanical potentiometer. The low terminal is equivalent to one of the fixed terminals of a mechanical potentiometer. Chip Select. The device is selected when the CS input is LOW, and de-selected when CS is high. Supply Voltage.
REV 1.9 4/3/03
www.xicor.com
2 of 10
X9318
ABSOLUTE MAXIMUM RATINGS Junction Temperature under bias ......-65C to +135C Storage temperature .........................-65C to +150C Voltage on CS, INC, U/D and VCC with respect to VSS ................................. -1V to +7V RH, RW, RL to ground .......................................... +10V Lead temperature (soldering 10 seconds)..........300C IW (10 seconds) ................................................. 6mA COMMENT Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only; 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 CHARACTERISTICS (VCC = 5V 10%, TA = Full Operating Temperature Range unless otherwise stated) Limits Symbol Parameter
End to end resistance tolerance VRH/RL RW IW RH/RL terminal voltage Power rating Wiper resistance Wiper current(5) Noise(7) Resolution Absolute linearity Relative linearity
(1)
Min.
-20 VSS
Typ.(4)
Max.
+20 8 25
Unit
% V mW mA dBV %
Test Conditions/Notes
See ordering information for values VSS = 0V IW = 1mA See test circuit Ref: 1kHz V(RH) = 8V, V(RL) = 0V
40 -3.0 -120 1 -1 -0.2 coefficient(5)
(5),(6)
200 +3.0
+1 +0.2 300 +20 10/10/25 5.5
MI(3) MI(3) ppm/C ppm/C pF V
(2)
RTOTAL temperature CH/CL/CW VCC
(5)
Ratiometric temperature coefficient Potentiometer capacitances Supply Voltage
-20 4.5
See equivalent circuit
REV 1.9 4/3/03
www.xicor.com
3 of 10
X9318
D.C. OPERATING CHARACTERISTICS (VCC = 5V 10%, TA = Full Operating Temperature Range unless otherwise stated) Limits Symbol
ICC
Parameter
VCC active current (Increment)
Min.
Typ.(4)
1
Max.
3
Unit
mA
Test Conditions
CS = VIL, U/D = VIL or VIH and INC = 0.4V/2.4V @ min. tCYC RL, RH, RW not connected CS 2.4V, U/D and INC = 0.4V RL, RH, RW not connected VIN = VSS to VCC
ISB ILI VIH VIL CIN(5)
Standby supply current CS, INC, U/D input leakage current CS, INC, U/D input HIGH voltage CS, INC, U/D input LOW voltage CS, INC, U/D input capacitance -10 2 -1
300
1000 +10 VCC + 1 0.8 10
A A V V pF
VCC = 5V, VIN = VSS, TA = 25C, f = 1MHz
ENDURANCE AND DATA RETENTION (VCC = 5V 10%, TA = Full Operating Temperature Range) Parameter
Minimum endurance Data retention
Min.
100,000 100
Unit
Data changes per bit Years
Notes: (1) Absolute linearity is utilized to determine actual wiper voltage versus expected voltage = [V(R W(n)(actual))-V(RW(n)(expected))]/MI V(RW(n)(expected)) = n(V(RH)-V(RL))/99 + V(RL), with n from 0 to 99. (2) Relative linearity is a measure of the error in step size between taps = [V(RW(n+1))-(V(RW(n)) + MI)]/MI (3) 1 Ml = Minimum Increment = [V(RH)-V(RL)]/99. (4) Typical values are for TA = 25C and nominal supply voltage. (5) This parameter is not 100% tested. (6) Ratiometric temperature coefficient = (V(RW)T1(n)-V(RW)T2(n))/[V(RW)T1(n)(T1-T2) x 106], with T1 & T2 being 2 temperatures, and n from 0 to 99. (7) Measured with wiper at tap position 31, RL grounded, using test circuit.
Test Circuit
Equivalent Circuit
RTOTAL RH CH Force Current 10pF RW CW 25pF CL 10pF RL
Test Point
RW
A.C. CONDITIONS OF TEST
Input pulse levels Input rise and fall times Input reference levels
REV 1.9 4/3/03
0.8V to 2.0V 10ns 1.4V
www.xicor.com
4 of 10
X9318
A.C. OPERATING CHARACTERISTICS (VCC = 5V 10%, TA = Full Operating Temperature Range unless otherwise stated) Limits Symbol
tCl tlD(5) tDI(5) tlL tlH tlC tCPHS tCPHNS(5) tIW tCYC tR, tF(5) tPU(5) tR VCC(5) CS to INC setup INC HIGH to U/D change U/D to INC setup INC LOW period INC HIGH period INC inactive to CS inactive CS deselect time (STORE) CS deselect time (NO STORE) INC to RW change INC cycle time INC input rise and fall time Power up to wiper stable VCC power-up rate 0.2 4 500 500 50
Parameter
Min.
100 100 1 1 1 1 20 1
Typ.(4)
Max.
Unit
ns ns s s s s ms s
100
500
s s s s V/ms
POWER UP AND DOWN REQUIREMENTS The recommended power up sequence is to apply VCC/VSS first, then the potentiometer voltages. During powerup, the data sheet parameters for the DCP do not fully apply until 1 millisecond after VCC reaches its final value. The VCC ramp spec is always in effect. In order to prevent unwanted tap position changes, or an inadvertant store, bring the CS and INC high before or concurrently with the VCC pin on powerup. A.C. TIMING
CS tCYC tCI INC tID tDI tF tIL tIH tIC tCPHS 90% 90% 10% tR
tCPHNS
U/D tIW RW MI (3)
REV 1.9 4/3/03
www.xicor.com
5 of 10
X9318
PIN DESCRIPTIONS RH and RL The high (RH) and low (RL) terminals of the X9318 are equivalent to the fixed terminals of a mechanical potentiometer. The terminology of RL and RH 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. RW Rw 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 40. 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 X9318 will be placed in the low power standby mode until the device is selected once again. PIN CONFIGURATION
DIP/SOIC INC U/D RH VSS 1 2 3 4 X9318 8 7 6 5 VCC CS RL RW
PIN NAMES Symbol
RH RW RL VSS VCC U/D INC CS
Description
High terminal Wiper terminal Low terminal Ground Supply voltage Up/Down control input Increment control input Chip select control input
PRINCIPLES OF OPERATION There are three sections of the X9318: the control section, the nonvolatile memory, and the resistor array. The 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. 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. Electronic switches at either end of the array and between each resistor provide an electrical connection to the wiper pin, RW. The wiper acts like its mechanical equivalent and does not move beyond the first or 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 tIW (INC to VW change). The RTOTAL value for the device can temporarily be reduced 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.
REV 1.9 4/3/03
www.xicor.com
6 of 10
X9318
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 memory whenever CS transitions HIGH while the INC input is also HIGH. The system may select the X9318, 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 changed by the system or until a powerup/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 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 device and then move the wiper up and down until the proper trim is attained. MODE SELECTION CS
L L H H X L L L
INC
U/D
H L X X X H L Wiper up Wiper down
Mode
Store wiper position to nonvolatile memory Standby No store, return to standby Wiper Up (not recommended) Wiper Down (not recommended)
REV 1.9 4/3/03
www.xicor.com
7 of 10
X9318
APPLICATIONS INFORMATION Electronic digitally controlled (XDCP) potentiometers provide three powerful application advantages; (1) the variability 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
VREF RH RW VREF
RL I
Three terminal potentiometer; variable voltage divider
Two terminal variable resistor; variable current
Basic Circuits
Buffered Reference Voltage R1 +V +5V VREF RW + - LMC7101 VOUT +V VOUT = VW/RW (a) (b) RW RW X 100K +8V 100K VO = (R2/R1)VS - + VO LMC7101 VS Cascading Techniques +V +V R1 R2 Single Supply Inverting Amplifier +8V
Voltage Regulator
Offset Voltage Adjustment
Comparator with Hysteresis
VIN
317 R1
VO (REG)
R1 VS 100K -
R2 VS +12V VO
LT311A
- + VO
Iadj R2 10K 10K VO (REG) = 1.25V (1+R2/R1)+Iadj R2 +12V 10K
+ LMC7101
VUL = {R1/(R1+R2)} VO(max) VLL = {R1/(R1+R2)} VO(min)
(for additional circuits see AN115) 8 of 10
}
R1
}
R2
REV 1.9 4/3/03
www.xicor.com
X9318
PACKAGING INFORMATION 8-Lead Plastic Small Outline Package, Type S (8-lead SOIC)
0.150 (3.80) 0.228 (5.80) 0.158 (4.00) 0.244 (6.20) Pin 1 Index Pin 1
0.014 (0.35) 0.019 (0.49) 0.188 (4.78) 0.197 (5.00) (4X) 7
0.053 (1.35) 0.069 (1.75) 0.004 (0.19) 0.010 (0.25)
0.050 (1.27)
0.010 (0.25) X 45 0.020 (0.50)
0.050"Typical
0 - 8 0.0075 (0.19) 0.010 (0.25) 0.016 (0.410) 0.037 (0.937) 0.250"
0.050" Typical
FOOTPRINT
0.030" Typical 8 Places
NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS)
REV 1.9 4/3/03
www.xicor.com
9 of 10
X9318
PACKAGING INFORMATION
8-Lead Plastic, DIP, Package Code P8
0.430 (10.92) 0.360 (9.14)
0.260 (6.60) 0.240 (6.10) Pin 1 Index Pin 1 0.300 (7.62) Ref. Half Shoulder Width On All End Pins Optional Seating Plane 0.150 (3.81) 0.125 (3.18) 0.060 (1.52) 0.020 (0.51)
0.145 (3.68) 0.128 (3.25) 0.025 (0.64) 0.015 (0.38) 0.065 (1.65) 0.045 (1.14) 0.020 (0.51) 0.016 (0.41)
0.110 (2.79) 0.090 (2.29)
.073 (1.84) Max.
0.325 (8.25) 0.300 (7.62)
Typ. 0.010 (0.25)
0 15
NOTE: 1. ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 2. PACKAGE DIMENSIONS EXCLUDE MOLDING FLASH
LIMITED WARRANTY
(c)Xicor, Inc. 2003 Patents Pending
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, BiasLock 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.
REV 1.9 4/3/03
www.xicor.com
Characteristics subject to change without notice.
10 of 10

▲Up To Search▲

Price & Availability of X9318

	To Download X9318 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .