ADLINK PXIe-9908 SMU Deployment and Configuration Guide

ADLINK PXIe-9908 High Density SMU Module Deployment and Accuracy Optimization Guide

In application scenarios such as Mini/Micro LED wafer testing, IC characteristic analysis, and high-precision semiconductor device characterization, the four quadrant output capability, multi-channel density, and measurement accuracy of the source measurement unit (SMU) directly determine the testing efficiency and data reliability. ADLINK PXIe-9908 is an 8-channel, 4-quadrant, high-density source measurement module that supports precision source output and measurement of ± 100 V/100 mA, and integrates remote (4-wire) sensing and protection (Guard) functions, which can significantly reduce cable errors in low-voltage and low current measurements. This article is aimed at automation testing system engineers, providing a complete engineering practice guide from module installation, connector pin definition, cascade mode configuration, precision calibration, driver software deployment to multi-channel synchronous applications.

Product positioning and core values

PXIe-9908 is a 3U PXI Express module designed by ADLINK for high-density, multi-channel SMU requirements. It integrates 8 independent source measurement channels on a single card, each with four quadrant working capability (source/sink current and voltage), suitable for capacitor voltage (C-V), current voltage (I-V) characteristic testing, LED forward voltage/reverse leakage current testing, battery charging and discharging simulation, and industrial process control scenarios.

The core highlights include:

8-channel high-density: Single slot or dual slot versions are available, greatly saving chassis space.

Wide range coverage: Voltage source/measurement range -10 V~+20 V (± 30 V in cascade mode), current source/measurement range 100 nA~100 mA, and supports ± 100 V voltage measurement (limited to 10 μ A current range only).

High speed sampling and updating: maximum measurement sampling rate of 1 MS/s, maximum source update rate of 100 kHz, source event delay as low as 5 μ s, suitable for dynamic testing.

Remote sensing (4-wire) and protection: eliminate the influence of wire resistance, and use Guard terminals to reduce leakage current and improve low current measurement accuracy.

Flexibility: Supports cascading mode (connecting two channels in series to increase the voltage to ± 30 V, but halving the number of channels to 4).

Detailed explanation of technical specifications

2.1 Electrical Scope and Accuracy

Voltage source/measurement range: -10 V~+20 V (single channel); ± 30 V after cascading; measurement can be extended to ± 100 V (limited to 10 μ A current range only).

Current source/measurement range: 100 mA, 10 mA, 2 mA, 200 μ A, 40 μ A, 10 μ A, 5 μ A, 1 μ A, 100 nA (9 levels in total).

Resolution: 18 bits (internal DAC/ADC).

Power output: maximum 2 W per channel (total 16 W for 8 channels); The maximum power for a single channel in cascade mode is 3 W (4 channels totaling 12 W).

Accuracy index (within 1 year calibration period, 25 ° C ± 5 ° C):

Voltage source/measurement accuracy: ± 0.02% range ± 2 mV (-10~20V and ± 30V range); ± 100V measurement accuracy ± 0.02% ± 15 mV.

Current source/measurement accuracy: High gear (100mA/10mA/2mA) ± 0.05% ± several μ A; At low gears (200 μ A and below), the accuracy remains at 0.05% or 0.1% (100nA gear), and the bias error is as low as 100 pA.

2.2 Trigger and Timing

Input triggers: Start, Source Sequence Advance, Measure.

Output trigger: Source Complete、Sequence Iteration Complete、Sequence Engine Done、Measure Complete。

These trigger signals can be coordinated with other modules through the PXI backplane trigger bus to achieve synchronization of complex test sequences.

2.3 Environment and Power Consumption

Working temperature: 0 ℃~50 ℃; Storage temperature: -20 ℃~70 ℃.

Humidity: Operating at 10%~90% non condensing; Store 5%~95% non condensable.

Power consumption: typical values of 3.3V/2.804mA, 12V/1280.22mA; At full load, 3.3V/2.814mA, 12V/4225.45mA (i.e.+12V is about 4.23A, about 50.7W), it is necessary to ensure the power supply margin of the chassis backplane.

Mechanical installation and connector definition

3.1 Module size

PXIe-9908 offers two mechanical versions:

Double slot version: Size 209.9 mm × 40.3 mm × 130.6 mm, suitable for scenarios that require more heat dissipation or circuit expansion.

Single slot version: Size 209.9 mm x 20 mm x 130.6 mm, compact design, suitable for high-density installation.

3.2 Front panel connector (62 pin D-Sub female socket)

All signals are led out through a high-density 62 pin D-Sub connector (CN1), and the key pin assignments are as follows (taking channel 0 as an example, and so on for other channels):

CHx Output HI: High end output (forced terminal).

CHx Output LO: Low end output (return terminal).

CHx Sense HI: Remote sensing high-end (positive).

CHx Sense LO: Remote sensing low-end (negative).

CHx Guard: A protective terminal driven by an active driver, with an output potential equal to HI, used to shield the leakage path (usually connected to the cable shielding layer).

En_100V: Enable ± 100V measurement function (En_100V Source needs to be short circuited to En_100V, otherwise this function will be disabled).

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.

Preheat thoroughly and perform self calibration.

Heat dissipation requirements:

When the module is at full power (50W), significant heat is generated to ensure the normal operation of the chassis fan, and adjacent slots are left with gaps or filled with baffles to maintain the air duct.

Calibration and maintenance

Users can trigger Auto Calibration through the API without the need for an external standard table.

The calibration constants are stored in two banks in EEPROM: Bank 0 (factory read-only) and Bank 1 (user writable). By default, Bank 0 is loaded. If self calibration values are required, Bank 1 can be activated through software settings.

After calibration, it is recommended to re validate the accuracy of critical channels to ensure compliance with specifications.