National Instruments PXI-4110 Manual

CALIBRATION PROCEDURE
NI PXI-4110
Triple-output Programmable DC Power Supply
This document contains information for calibrating the NI PXI-4110 (NI 4110) triple-output
programmable DC power supply. For more information about calibration, visit
ni.com/calibration.
Contents
Software.................................................................................................................................... 2
Related Documentation ............................................................................................................ 3
Password................................................................................................................................... 3
Calibration Interval................................................................................................................... 3
Test Equipment......................................................................................................................... 4
Test Conditions......................................................................................................................... 4
Calibration Procedures ............................................................................................................. 5
Initial Setup....................................................................................................................... 5
Verification ....................................................................................................................... 6
Verifying Voltage Programming Accuracy.............................................................. 7
Verifying Voltage Measurement Accuracy.............................................................. 8
Verifying Current Programming Accuracy .............................................................. 10
Verifying Current Measurement Accuracy .............................................................. 12
Verifying Load Regulation....................................................................................... 14
Verifying Line Regulation........................................................................................ 19
Adjustment........................................................................................................................ 24
Considerations .......................................................................................................... 25
Adjusting Voltage Programming Accuracy ............................................................. 26
Adjusting Voltage Measurement Accuracy.............................................................. 27
Adjusting Current Programming Accuracy.............................................................. 28
Adjusting Current Measurement Accuracy .............................................................. 29
Where to Go for Support .......................................................................................................... 30

2|ni.com |NI PXI-4110 Calibration Procedure
Software
To calibrate the NI 4110, you must install the NI-DCPower instrument driver version 1.0 or later
on the Windows calibration system. You can download NI-DCPower at ni.com/downloads.
NI-DCPower supports programming an external calibration in the LabVIEW and C application
development environments (ADEs). When you install NI-DCPower, you need to install support
only for the application software that you intend to use.
LabVIEW support is in the nidcpower.llb file, and all calibration VIs are accessible from
the NI-DCPower Calibration palette. For LabWindows™/CVI™users, the NI-DCPower function
panel (nidcpower.fp) provides access to the calibration functions. Refer to Table 1 for file
locations.
Table 1. Calibration File Locations (NI-DCPower 1.0 or Later)
File Name and Location Description
IVI\Bin\nidcpower_32.dll NI-DCPower driver containing the entire
NI-DCPower API, including calibration
functions.
IVI\Lib\msc\nidcpower.lib NI-DCPower library for Microsoft C
containing the entire NI-DCPower API,
including calibration functions.
<LabVIEW>\instr.lib\niDCPower
Calibrate\nidcpower.llb
LabVIEW VI library containing VIs for
calling the NI-DCPower calibration API. You
can access calibration functions from the
NI-DCPower calibration section of the
LabVIEW function palette.
IVI\Drivers\niDCPower\
nidcpower.fp
LabWindows/CVI function panel file that
includes calibration function prototypes and
help on using NI-DCPower in the
LabWindows/CVI environment.
IVI\Include\nidcpower.h NI-DCPower header file, which you must
include in any C program accessing
calibration functions. This file includes the
entire NI-DCPower API, including calibration
functions.

NI PXI-4110 Calibration Procedure |© National Instruments |3
Related Documentation
Consult the following documents for information about the NI 4110, NI-DCPower, and your
application software. All documents are installed with the software and are located at Start»
All Programs»National Instruments»NI-DCPower»Documentation. You can also
download the latest versions of the documentation at ni.com/manuals.
Password
The default calibration password is NI.
Calibration Interval
National Instruments recommends that you perform a complete calibration for the NI 4110 at
least once a year. You can shorten this calibration interval based on the accuracy demands
of your application. Refer to the Where to Go for Support section for more information.
NI PXI-4110 Getting Started Guide
Contains instructions for NI 4110 installation, hardware installation, and hardware
programming.
NI PXI-4110 Specifications
Contains NI PXI-4110 specifications and calibration interval.
NI-DCPower Readme
Contains operating system and application software support in NI-DCPower.
NI DC Power Supplies and SMUs Help
Contains detailed information about the NI 4110.
LabVIEW Help
Contains LabVIEW programming concepts and reference information about
NI-DCPower VIs and properties.
NI-DCPower C Reference Help
Contains reference information for NI-DCPower C functions and NI-DCPower
C attributes.

4|ni.com |NI PXI-4110 Calibration Procedure
Test Equipment
Table 2 lists the equipment required to calibrate the NI 4110. If you do not have the
recommended equipment, select a substitute calibration standard using the specifications listed
in Table 2.
Test Conditions
Follow these guidelines to optimize the connections and the environment during calibration:
• Keep cabling wire as short as possible. Long cables and wires act as antennas, picking up
extra noise that can affect measurements.
• Verify that all connections, including front panel connections, are secure.
• Ensure that the PXI chassis fan speed is set to HI, that the fan filters are clean, and that the
empty slots contain filler panels. For more information, refer to the Maintain Forced-Air
Cooling Note to Users document available at ni.com/manuals.
• Keep relative humidity between 10% and 90%, noncondensing.
• Maintain an ambient temperature of 23 °C ± 10 °C for verification procedures and an
ambient temperature of 23 °C ± 1 °C for adjustment procedures.
• Allow a warm-up time of at least 15 minutes after the NI-DCPower driver is loaded. Unless
manually disabled, NI-DCPower automatically loads with the operating system and
enables the device. The warm-up time ensures that the measurement circuitry of the
NI 4110 is at a stable operating temperature.
Table 2. Required Equipment Specifications for NI 4110 Calibration
Required Equipment
Recommended
Equipment Specifications
Digital multimeter
(DMM)
NI PXI-4071 Vo l t a g e : ≤±50 ppm accuracy,
≤30 μV resolution;
Current: ≤±0.04% accuracy,
≤50 nA resolution
External load Clarostat 240C Power resistor decade box with a
range of 4 Ωto 25,000 Ω, an
accuracy of ±10%, and
minimum power rating of 40 W
per decade
Auxiliary power supply NI APS-4100 11 V to 15.5 V, 5 A
Twisted pair, shielded
cabling wire
—18 AWG to 22 AWG
Variable power supply Xantrex HPD 30-10 Variable between 11 V and
15.5V,5A

NI PXI-4110 Calibration Procedure |© National Instruments |5
• Use shielded copper wire for all cable connections to the device. Use twisted-pair wire to
eliminate noise and thermal offsets.
• Plug the chassis and the instrument standard into the same power strip to avoid ground
loops.
Calibration Procedures
The calibration process includes the following steps:
1. Initial Setup—Install the device and configure it in Measurement & Automation Explorer
(MAX).
2. Verification—Verify the existing operation of the device. This step confirms whether the
device is operating within its specified range prior to calibration.
3. Adjustment—Perform an external adjustment of the device that adjusts the calibration
constants with respect to a known voltage source. The adjustment procedure automatically
stores the calibration date on the EEPROM to allow traceability.
4. Reverification—Repeat the verification procedure to ensure that the device is operating
within its specifications after adjustment.
These steps are described in more detail in the following sections.
Note In some cases, a complete calibration procedure may not be required. Refer
to Where to Go for Support for more information.
Initial Setup
Refer to the NI PXI-4110 Getting Started Guide for information about how to install the
software and hardware and how to configure the device in MAX.
Tables 3 and 4 list configuration information for the calibration equipment required for
verification.
Table 3. Calibration Equipment Configuration for Voltage Programming and Measurement
Verification/Adjustment
NI 4110 Channel(s)
DMM*
Function Range†Input Impedance†
0
DC Voltage
10 V 10 GΩ
1, 2 100 V 10 MΩ
* Use the highest resolution available on the DMM.
† Assumes an NI 4071 DMM. For all other DMMs, use the range and input impedance closest to the
values listed in this table.

6|ni.com |NI PXI-4110 Calibration Procedure
Verification
The following performance verification procedures describe the sequence of operation and test
limits required to check the NI 4110, and assumes that adequate traceable uncertainties are
available for the calibration references.
Verification consists of generating and measuring a series of outputs using the NI 4110,
verifying the accuracy with the DMM, and comparing the results to the calibration test limits. If
the results fall within the test limits, the NI 4110 meets its published specifications, and
adjustment is optional. If the results fall outside of the test limits, you must adjust the NI 4110.
Verification tests the following NI 4110 specifications:
• Voltage programming accuracy
• Voltage measurement accuracy
• Current programming accuracy
• Current measurement accuracy
• Voltage load regulation
• Current load regulation
• Voltage line regulation
• Current line regulation
Verification of the NI 4110 is complete only after you successfully complete all tests in this
section.
Note If verification fails post-adjustment, confirm that you meet the required Test
Conditions before you return the NI 4110 to NI for repair.
Table 4. Calibration Equipment Configuration for Current Output and Measurement
Verification/Adjustment
NI 4110 Channel(s)
DMM*
Function Range Input Impedance†
0
DC Current
1A
10 MΩ1, 2 (20 mA range) 0.1 A
1, 2 (1 A range) 1A
* Use the highest resolution available on the DMM.
†Assumes an NI 4071 DMM. For all other DMMs, use the range and input impedance closest to the
values listed in this table.

NI PXI-4110 Calibration Procedure |© National Instruments |7
Verifying Voltage Programming Accuracy
To verify the voltage programming accuracy, compare a set of requested voltage test points to
measurements of the actual voltage at the output by the DMM. Refer to Figure 1 for the
necessary connections.
Figure 1. Voltage Verification Connection Diagram
Table 5 lists the voltage output test points that you must request for each channel with the
NI 4110 and measure with the DMM to complete verification. Take voltage measurements using
the DMM at each voltage test point and compare the reading with the value from the Output
column of Table 5. Verify that the measurement error falls between the tolerances listed in the
Test Limit (V) column for the iteration of channel x in Table 5. If the output voltage that you
measure is outside the test limit, you must adjust the NI 4110.
To ensure that the system has had adequate time to settle, wait one second after requesting a new
voltage before taking a measurement with the DMM.
The voltage measurement test limits in Table 5 are derived from the voltage programming
accuracy specifications plus an offset voltage.
NI 4110
HI
LO
+
–
DMM
Voltage
Mode

8|ni.com |NI PXI-4110 Calibration Procedure
Verifying Voltage Measurement Accuracy
To verify the voltage measurement accuracy of the NI 4110, compare a set of voltage
measurements from the NI 4110 to measurements of the actual voltage at the output by a DMM.
Refer to Figure 1 for the necessary connections. When taking measurements with the NI 4110,
set the Samples to Average property to 300.
Table 6 lists the voltage test points that you must measure and request for each channel with both
the DMM and the NI 4110 to complete verification. Take voltage measurements using the DMM
at each test point, and then take voltage measurements using the NI 4110 at each test point.
Compare the two values. Verify that the measurement error falls between the tolerances listed in
the Test Limit (V) column for the iteration of channel x in Table 6. If the output voltage that you
measure is outside the test limit, you must adjust the NI 4110.
Table 5. NI 4110 Output Parameters and Test Limits for Voltage Programming
Accuracy Verification
Channel Iteration Output (V) Current Limit (A) Test Limit (V)
0 1 0 0.5 ±0.00400
21.5 ±0.00475
3 3 ±0.00550
44.5 ±0.00625
5 6 ±0.00700
1 1 0 ±0.01000
2 5 ±0.01250
3 10 ±0.01500
4 15 ±0.01750
5 20 ±0.02000
2 1 0 ±0.01000
2-5 ±0.01250
3-10 ±0.01500
4-15 ±0.01750
5-20 ±0.02000

NI PXI-4110 Calibration Procedure |© National Instruments |9
To ensure the system has had adequate time to settle, wait one second after requesting a new
voltage before taking a measurement with the DMM and the NI 4110.
The voltage measurement test limits in Table 6 are derived from the voltage measurement
accuracy specifications plus an offset voltage.
Table 6. NI 4110 Output Parameters and Test Limits for Voltage Measurement
Accuracy Verification
Channel Iteration Output (V) Current Limit (A) Test Limit (V)
0 1 0 0.5 ±0.004000
21.5 ±0.004750
3 3 ±0.005500
44.5 ±0.006250
5 6 ±0.007000
1 1 0 ±0.005000
2 5 ±0.007500
3 10 ±0.010000
4 15 ±0.012500
5 20 ±0.015000
2 1 0 ±0.005000
2-5 ±0.007500
3-10 ±0.010000
4-15 ±0.012500
5-20 ±0.015000

10 |ni.com |NI PXI-4110 Calibration Procedure
Verifying Current Programming Accuracy
Note Program the NI 4110 in DC Voltage mode for this test.
To verify current programming accuracy, compare a set of requested current test points to
measurements of the actual current at the output by the DMM. Connect an NI APS-4100
auxiliary power supply for this verification procedure. Refer to Figure 2 for the necessary
connections.
Figure 2. Current Accuracy Verification Test System
Configure the DMM using the configuration settings for channel xin Table 4. Table 7 lists the
voltage test points and external load settings that you must measure in DC Voltage mode for each
current range to complete verification. For example, the 1 A range requires verification at the
following outputs from the NI 4110, taking measurements using the external DMM at each
point:
•0.02A
•0.25A
•0.5A
•0.75A
•1.0A
The value in the Output (A) column of Table 7 is the current limit value that you should
program for each setpoint.
Note The values in the Output (A) column are the settings for the current limit. This
column is labeled Output because the current limit is the value that the NI 4110
generates.
Load
+
–
NI PXI-4110
HI
LO
DMM
Current
Mode
+
–
Auxiliary Power
Supply
NI APS-4100
+
–
AUX IN +
AUX IN –

NI PXI-4110 Calibration Procedure |© National Instruments |11
To ensure the system has had adequate time to settle, wait three seconds after requesting a new
current before taking a measurement with the DMM. The current programming test limits in
Table 7 are derived from the current programming accuracy specifications.
Table 7. NI 4110 Output Parameters and Test Limits for Current
Programming Accuracy Verification
Channel(s)
Output
(V)
Current
Range Iteration
Equivalent
Resistance
(Ω)
Output
(A)
Test Limit
(A)
0 6 1A 1 150 0.020000 ±0.004030
2 12 0.250000 ±0.004375
3 6 0.500000 ±0.004750
4 4 0.750000 ±0.006063
5 3 1.000000 ±0.008000
1 16 1A 1 500 0.020000 ±0.004030
2 40 0.250000 ±0.004375
3 20 0.500000 ±0.004750
4 13 0.750000 ±0.006063
5 9 1.000000 ±0.008000
1 16 20 mA 1†25,000 0.000400 ±0.000060
22,000 0.005000 ±0.000068
31,000 0.010000 ±0.000075
4 670 0.015000 ±0.000083
5 500 0.020000 ±0.000090
2-16 1A 1 500 0.020000 ±0.004030
2 40 0.250000 ±0.004375
3 20 0.500000 ±0.004750
4 13 0.750000 ±0.006063
5 9 1.000000 ±0.008000

12 |ni.com |NI PXI-4110 Calibration Procedure
Verifying Current Measurement Accuracy
Note Program the NI 4110 in DC Voltage mode for this test.
Note Set the Current Limit and the Current Limit Range to the values in the
Current Range column of Table 8.
To verify current measurement accuracy, compare a set of voltage setpoints as measured by an
external DMM to the measured voltage reported by the NI 4110. Connect an NI APS-4100
auxiliary power supply for this verification procedure. Refer to the following figure for the
necessary connections.
Figure 3. Current Measurement Connection Diagram
2-16 20 mA 1*25,000 0.000400 ±0.000060
22,000 0.005000 ±0.000068
31,000 0.010000 ±0.000075
4 670 0.015000 ±0.000083
5 500 0.020000 ±0.000090
*Wait 15 s for the output of the NI 4110 to settle.
Table 7. NI 4110 Output Parameters and Test Limits for Current
Programming Accuracy Verification (Continued)
Channel(s)
Output
(V)
Current
Range Iteration
Equivalent
Resistance
(Ω)
Output
(A)
Test Limit
(A)
Load
+
–
NI PXI-4110
HI
LO
DMM
Current
Mode
+
–
Auxiliary Power
Supply
NI APS-4100
+
–
AUX IN +
AUX IN –

NI PXI-4110 Calibration Procedure |© National Instruments |13
Configure the DMM using the configuration settings for channel xin Table 4. Table 8 lists the
voltage test points and external load settings that you must measure in DC Voltage mode for each
current range to complete verification. For example, the 1 A range requires verification at
0.02 A, 0.25 A, 0.5 A, 0.75 A, and 1.0 A outputs from the NI 4110, taking measurements using
the external DMM and NI 4110 at each point. When taking measurements with the NI 4110, set
the Samples to Average property to 300.
To ensure the system has had adequate time to settle, wait three seconds after requesting a new
current before taking a measurement with the DMM and the NI 4110.
Verify that the measurement error falls between the absolute limits listed in the Test Limit for the
iteration of channel x in Table 8. If the measurement error is outside of the test limit, you must
adjust the NI 4110.
Table 8. 4110 Output Parameters and Test Limits for Current Measurement
Accuracy Verification
Channel(s)
Current
Range Iteration
Equivalent
Resistance
(Ω)
Output
(V)*
Test Limit
(A)
Published
Specification
(A)
01A 1open 0†±0.002000 ±0.004
2 5 1.25 ±0.002050 ±0.004375
3 5 2.5 ±0.002500 ±0.00475
4 5 3.75 ±0.004000 ±0.006063
5 5 5 ±0.005500 ±0.008000
1, 2 1A 1open 0†±0.002000 ±0.004
2 20 ±5 ±0.002050 ±0.004375
3 20 ±10 ±0.002500 ±0.00475
4 20 ±15 ±0.004000 ±0.006063
5 20 ±20 ±0.005500 ±0.008000

14 |ni.com |NI PXI-4110 Calibration Procedure
Verifying Load Regulation
Complete the load regulation test to verify that the output voltage falls within specified limits
when the load current changes or to verify that the output current falls within specified limits
when the load voltage changes. Each test requires two resistors to vary the load voltage or
current.
Note Load Voltage Verification results are dependent upon voltage and current
measurement accuracy. Any failure of the Voltage Measurement Verification or
Current Measurement Verification steps may result in a failure of the Load
Regulation Verification steps.
Connect the NI APS-4100 to the Aux Power Input connections for load regulation tests.
1, 2 20 mA 1open 0†±0.000012 ±0.000035
21,000 ±5 ±0.000020 ±0.000043
31,000 ±10 ±0.000027 ±0.000050
41,000 ±15 ±0.000035 ±0.000058
51,000 ±20 ±0.000042 ±0.000065
*When verifying channel 1, the Output is positive. When verifying channel 2, the Output is negative.
†To facilitate an accurate measurement using an Output value of 0, verify that the DMM and the external
load are disconnected from the NI 4110. For all other Output values, the DMM and the external load are
connected to the NI 4110.
Table 8. 4110 Output Parameters and Test Limits for Current Measurement
Accuracy Verification (Continued)
Channel(s)
Current
Range Iteration
Equivalent
Resistance
(Ω)
Output
(V)*
Test Limit
(A)
Published
Specification
(A)

NI PXI-4110 Calibration Procedure |© National Instruments |15
Voltage Load Regulation
To verify voltage load regulation, use the NI 4110 in constant voltage mode and confirm that the
output voltage change falls within calculated limits while varying the load current using different
resistors. Table 10 lists the resistance values and measurements needed to complete verification.
Refer to Figure 4 for the necessary connections.
Figure 4. Voltage Load Regulation Verification Connection Diagram
Complete the following steps to verify voltage load regulation:
1. For each test, connect the first specified resistance (R1) to the specified channel of the
NI 4110.
2. While taking a current measurement with the NI 4110 (I1), use the DMM to measure the
voltage across the output of the NI 4110 (V1).
3. Change the load from R1to R2and repeat the previous step.
4. Record the voltage and current measurements for both resistances.
5. Calculate the Voltage Change Limit using the formulas in the following table, where the
current is in mA.
6. Subtract the two voltage measurements V1- V2to calculate the Voltage Change. The test
passes if the Voltage Change falls within the calculated Voltage Change Limit.
Table 9. NI 4110 Voltage Load Regulation Voltage Change Limit Formulas
Channels Voltage Change Limit
0± (I1 - I2) × 2.52 × 10-5
1 and 2 ± (I1 - I2) × 2.00 × 10-5
NI PXI-4110
Load
+
–
+
–
HI
LO
DMM
Voltage
Mode
Auxiliary Power
Supply
+
–
AUX IN +
AUX IN –
NI APS-4100

16 |ni.com |NI PXI-4110 Calibration Procedure
Table 10. NI 4110 Voltage Load Regulation Verification Points
Channel VRange I Range I Limit V Level Load R1Load R2
Measured Voltage
Change
Limit (V)
Voltage
Change (V)
I1(mA) V1(V) I2(mA) V2(V)
06V 1A 1A 6V 620 Ω7Ω
120 V 1A 1A 10 V 1kΩ11 Ω
220 V 1A 1A -10 V 1kΩ11 Ω

NI PXI-4110 Calibration Procedure |© National Instruments |17
Current Load Regulation
To verify current load regulation, use the NI 4110 in Constant Current mode and confirm that
the output current change falls within calculated limits while varying the load voltage using
different resistors. Table 12 lists the resistance values and measurements needed to complete
verification. Refer to Figure 5 for the necessary connections.
Figure 5. Current Load Regulation Verification Connection Diagram
Complete the following steps to verify current load regulation:
1. For each test, connect the first specified resistance (R1) to the specified channel of the
NI 4110.
2. While taking a voltage measurement with the NI 4110 (V1), use the DMM in series to
measure the output current (I1).
3. Change the load from R1to R2and repeat the previous step.
4. For each test, the units for all current measurements and calculations should be the same as
the I Range unit. Record the current and voltage measurements for both resistances.
5. Calculate the Current Change Limit using the formulas shown in the following tables:
6. Subtract the two current measurements I1 - I2to calculate the Current Change. The test
passes if the Current Change falls within the calculated Current Change Limit.
Table 11. NI 4110 Current Load Regulation Current Change Limit Formulas
Channels Current Range Current Change Limit
01A ±2.00 × 10-4 × (V1 - V2)
1 and 2 20 mA ±6.00 × 10-7 × (V1 - V2)
1 and 2 1A ±7.00 × 10-5 × (V1 - V2)
Load
+
–
NI PXI-4110
HI
LO
DMM
Current
Mode
+
–
Auxiliary Power
Supply
NI APS-4100
+
–
AUX IN +
AUX IN –

18 |ni.com |NI PXI-4110 Calibration Procedure
Table 12. NI 4110 Current Load Regulation Verification Points
Channel V Range I Range VLimit I Level Load R1Load R2
Measured Current
Change
Limit (A)
Current
Change (A)
I1(A) V1(V) I2(A) V2(V)
06V 1A 6V 500 mA 10 Ω4Ω
120 V 20 mA 20 V 10 mA 1.8 kΩ200 Ω
120 V 1A 20 V 500 mA 36 Ω4Ω
220 V 20 mA 20 V -10 mA 1.8 kΩ200 Ω
220 V 1A 20 V -500 mA 36 Ω4Ω

NI PXI-4110 Calibration Procedure |© National Instruments |19
Verifying Line Regulation
Complete the line regulation test to verify that the output voltage falls within specified limits
when the line voltage coming from the auxiliary power supply changes or that the output current
falls within specified limits when the line voltage changes. Each test requires a variable auxiliary
power supply to vary the line voltage or current. An NI APS-4100 is not sufficient for verifying
line regulation because the output voltage is fixed. Run this test only after the
Verifying Voltage Measurement Accuracy and Verifying Current Measurement Accuracy tests
pass.
Voltage Line Regulation
To verify voltage line regulation, use the NI 4110 in Constant Voltage mode and confirm that
the output voltage change falls within calculated limits while varying the line voltage using a
variable power supply. Table 14 lists the voltage values and measurements needed to complete
verification. Refer to Figure 6 for the necessary connections.
Figure 6. Voltage Line Regulation Verification Connection Diagram
NI PXI-4110
+
–
HI
LO
DMM
Voltage
Mode
Variable Power
Supply
+
–
AUX IN +
AUX IN –

20 |ni.com |NI PXI-4110 Calibration Procedure
Complete the following steps to verify voltage load regulation:
1. For each test, adjust the external variable power supply to the specified voltage (Vext1) listed
in Table 14.
2. Set the NI 4110 to output the voltage specified in Table 14.
3. Use the DMM to measure the voltage across the output of the specified channel of the
NI 4110 (V1).
4. Change the external variable power supply voltage from Vext1 to Vext2 and repeat the
previous step.
5. Record the NI 4110 output voltage measurements for both external voltages.
6. Calculate the Voltage Change Limit using the formula shown in the following table:
Table 13. NI 4110 Voltage Line Regulation Voltage Change Limit Formulas
7. Subtract the two voltage measurements V1 - V2to calculate the Voltage Change. The test
passes if the Voltage Change falls within the calculated Voltage Change Limit.
Channel Voltage Change Limit
1 and 2 ± ((V1× 1.00 × 10-4) + 1.00 × 10-3) × (Vext1 - Vext2)