Cal HI/LO/Sense: For external calibration only, not connected during normal use.
Important Note:
Remote sensing (4-wire) must be connected to the far end of the device under test (DUT) to compensate for cable voltage drop and obtain the true terminal voltage.
Guard terminals should be connected to the shielding layer of coaxial cables or the inner shielding layer of triple coaxial cables to reduce stray capacitance and leakage current, especially in nA/pA level measurements.
Unused channels should connect Sense HI to Output HI and Sense LO to Output LO (or remain floating, but refer to manual recommendations).
Cascade Mode configuration
Cascade mode allows two channels to be connected in series, expanding the voltage range from -10~20V to ± 30V, but halving the number of channels (8 channels to 4 channels). Specific operations:
Connect the output HI of channel 0 to the output LO of channel 1 (i.e. in series), and use the output LO of channel 0 and the output HI of channel 1 as new differential output terminals.
Channels 0 and 1 need to be set to the same current range and enable cascade mode simultaneously.
After cascading, the maximum power of a single channel is increased to 3W (a total of 12W for 4 channels), but the current capability is still limited by the range of a single channel.
This mode is suitable for scenarios that require high voltage but low current demand (such as high-voltage diode breakdown testing).

Accuracy assurance and automatic calibration
5.1 Preheating and Calibration
The module needs to be preheated for at least 30 minutes to achieve specification accuracy.
The recommended calibration cycle is 1 year, which can be automatically calibrated using a built-in reference voltage (specific value not specified). The driver API provides calibration functions that require external disconnection during execution, and the process is automatically completed.
5.2 Error Sources and Compensation
Offset error: In low current settings (<1 μ A), attention should be paid to the ambient temperature and thermoelectric potential, and Guard terminals can be used to reduce leakage current.
Gain error: can be linearly corrected through front-end software.
Using 4-wire measurement can effectively eliminate the effects of contact resistance and line resistance (which may introduce tens of milliohms per meter of cable and generate tens of mV errors at high currents).
Driver installation and software ecosystem
PXIe-9908 is based on the ADLINK MAPS Core software platform and supports Windows 10/11 64 bit systems. Drivers and SDKs can be downloaded from the product page:
https://www.adlinktech.com.cn/products/pxi_pxie_platform/pxi_pxie_modules/pxie-9908
6.1 Installation steps
Install MAPS Core (including ACE device management tool).
Install SMU_SDK (including C/C++API, LabVIEW library, and sample programs).
After connecting the module, ACE can recognize the device and configure DMA buffers, aliases, etc.
6.2 Software Front Panel
The installation package provides a graphical soft panel, divided into four areas:
Hardware information: Display firmware version.
Channel configuration: Set the source mode (voltage/current), range, limit values, etc. for each channel.
Parameter application: One click configuration distribution.
Message panel: Display operational feedback.
The soft panel supports basic manual control and parameter verification, making it suitable for quick debugging.
6.3 Programming Interface
C/C++: Provides header files (. h), library files (. lib), and sample programs (such as single channel I-V scanning, pulse testing, etc.).
LabVIEW: Provides VI libraries and examples for easy integration into existing test sequences.
Python support (via MAPS Core API, but additional confirmation is required).
Multi channel synchronization and triggering applications
PXIe-9908 supports multi-channel independent operation and can also achieve synchronization by triggering the bus through PXI.
Trigger input: Start trigger can simultaneously start the measurement or source output of all channels.
Output trigger: The Source Complete pulse can be used to notify subsequent modules (such as switch matrices) to switch test points.
Through the "Sequence Engine", a step sequence can be defined, each step containing source settings, measurement timing, and triggering behavior, suitable for automated multi-point testing (such as wafer probe step scanning).
Typical application wiring and precautions
LED IV test:
Use a 4-wire connection: Force HI/Sense HI is connected to the LED anode, and Force LO/Sense LO is connected to the cathode.
Set the current source mode (such as 10mA), and the voltage range will automatically adapt.
When measuring forward voltage (VF) and reverse leakage current (IR), different current levels need to be used.
Microresistance measurement:
Using Kelvin connection (4-wire) to eliminate lead resistance.
Use high current (100mA) to improve signal-to-noise ratio, while utilizing remote sensing to accurately measure voltage drop.
Leakage current measurement (nA level):
Enable the Guard terminal and connect it to the cable shielding layer.
Maintain low humidity in the environment and use high insulation cables.