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).