The NI PXIe-4140 is a four-channel PXI Source Measure Unit (SMU) that combines precision voltage sourcing, current sourcing and electrical measurement in a compact, one-slot PXI Express module. Each channel supports four-quadrant operation across a ±10 V voltage range and ±100 mA current range.
With simultaneous high-speed measurements, programmable source sequencing and four-wire remote sensing, the PXIe-4140 is designed for semiconductor characterization, component testing, power-management IC validation and automated production test systems.
Key Features of the NI PXIe-4140
- Four independent SMU channels
- ±10 V programmable voltage range
- ±100 mA maximum source and sink current
- Four-quadrant source and sink operation
- 100 pA current sensitivity on the 10 µA range
- 600 kS/s maximum continuous measurement rate per channel
- Up to 100,000 source updates/s per channel for short sequences
- Four-wire remote sensing on every channel
- Local-sense and remote-sense connection modes
- Programmable slow, normal and fast transient responses
- Hardware triggering through PXI trigger lines
- One-slot 3U PXI Express form factor
PXIe-4140 Technical Specifications
| Product Model | PXIe-4140 |
|---|---|
| Part Number | 781742-01 |
| Product Type | PXI Source Measure Unit |
| Number of Channels | 4 |
| Operating Quadrants | Four-quadrant source and sink operation |
| Voltage Range | ±10 V |
| Current Ranges | 10 µA, 100 µA, 1 mA, 10 mA and 100 mA |
| Maximum Current | ±100 mA per channel |
| Maximum DC Sink Power | 1 W per channel |
| Voltage Resolution and Noise | 100 µV on the 10 V range |
| Best Current Resolution and Noise | 100 pA on the 10 µA range |
| Maximum Measurement Rate | 600 kS/s per channel, continuous |
| Maximum Source Update Rate | 100 k updates/s per channel for sequences shorter than 300 steps |
| Remote Sense | Four-wire remote sensing, up to 1 V lead drop per lead |
| Typical Settling Time | Less than 100 µs in fast transient response mode |
| Isolation | 60 VDC CAT I, channel to earth ground |
| Channel Isolation | Channels are isolated from earth ground but share a common LO |
| Front Connector | 25-position male D-SUB |
| Form Factor | 3U, one-slot PXI Express module |
| Operating Temperature | 0°C to 55°C |
| Recommended Calibration Interval | 1 year |
PXIe-4140 Part Number and Configuration
| Part Number | Configuration | Product Status |
|---|---|---|
| 781742-01 | PXIe-4140, 4-channel, ±10 V, ±100 mA PXI SMU | Mature |
The PXIe-4140 is classified as a mature NI product and is not recommended for new system designs. It remains suitable for maintaining, replacing or expanding compatible installed PXI test systems.
Four-Channel Source and Measurement Capability
Each PXIe-4140 channel can source voltage while measuring current or source current while measuring voltage. Four-quadrant operation allows the module to both deliver and absorb power, enabling it to simulate common power sources and electronic loads.
The four channels can be programmed independently, allowing one module to power and monitor multiple rails or devices in parallel. This high channel density helps reduce the number of instruments and PXI slots required in automated test systems.
Current Ranges and Measurement Sensitivity
The PXIe-4140 provides five programmable current ranges from 10 µA to 100 mA. The 10 µA range offers 100 pA resolution and noise performance, while higher ranges accommodate devices that require greater source or sink current.
Selecting the lowest suitable range improves low-current measurement performance. For devices with rapidly changing current consumption, automatic range selection or an appropriate fixed range can prevent overrange conditions while preserving measurement quality.
High-Speed Sampling and Source Sequencing
The PXIe-4140 supports continuous measurements at up to 600 kS/s per channel. It can also execute source sequences at up to 100,000 updates/s per channel when the sequence contains fewer than 300 steps.
These capabilities support transient-current capture, power-up sequence evaluation, voltage sweeps and fast automated test routines. Source, measure and sequence events can be synchronized with other PXI instruments using the chassis trigger lines.
Local Sense and Four-Wire Remote Sense
Local sensing uses the Output HI and Output LO terminals and is suitable when lead resistance has little effect on the required accuracy. Four-wire remote sensing adds Sense HI and Sense LO connections at the device under test.
Remote sensing compensates for voltage drops in test cables and fixture wiring, making it particularly useful at higher currents or when precise voltage delivery at the DUT is required. Guard connections can also help reduce leakage and parasitic capacitance in sensitive measurements.
Transient Response Modes
The PXIe-4140 provides preset slow, normal and fast transient response modes. Fast mode reduces settling time for compatible loads, while slower settings can improve stability when driving capacitive devices or complex test fixtures.
This model does not provide NI SourceAdapt programmable control-loop settings. Applications requiring customized SMU response characteristics should consider a compatible SourceAdapt-enabled model such as the PXIe-4141.
Typical PXIe-4140 Applications
- Semiconductor device characterization
- Power-management IC testing
- Voltage regulator and DC/DC converter validation
- Battery-powered device testing
- Quiescent-current measurement
- Multirail power sequencing
- Component current-voltage characterization
- Automated production testing
- Research and laboratory measurement systems
Software and Driver Support
The PXIe-4140 is controlled through the NI-DCPower instrument driver. Engineers can configure source modes, current limits, voltage limits, measurement apertures, triggering and advanced sequences using supported NI software environments.
Common development options include LabVIEW, LabWindows/CVI, C/C++, .NET and Python environments supported by the installed NI-DCPower driver version. Verify operating-system, driver and application-software compatibility when integrating the module into an existing system.
PXI Chassis and System Integration
The PXIe-4140 occupies one PXI Express peripheral slot and requires a compatible PXI Express chassis and controller. Adequate chassis cooling is important when multiple SMUs or other power-dissipating modules are installed together.
For a complete system, review the required terminal block, D-SUB cabling, test fixture, PXI controller and software licenses. The module uses a 25-position male D-SUB front-panel connector.
PXIe-4140 Troubleshooting
Why is the measured voltage lower than the programmed voltage?
Check whether the output has entered current-limit mode and confirm that the DUT current remains within the selected current range. Cable and fixture resistance can also create voltage drops. Use four-wire remote sensing when accurate voltage delivery at the DUT is required.
Why are low-current measurements noisy or unstable?
Select the lowest current range that accommodates the expected signal, increase the measurement aperture and use appropriate shielding and guarding. Allow sufficient warm-up time and perform self-calibration when required.
Why does the output oscillate with a capacitive load?
Try the normal or slow transient response setting and review the cable, fixture and DUT capacitance. The fastest response setting may not provide the best stability for every load.
Why can the channels not be independently floated?
The four channels are isolated from earth ground, but they share a common LO connection. Confirm that the DUT grounding arrangement is compatible with this architecture before wiring multiple devices or power rails.
PXIe-4140 Product Comparison
| Model | Channels | Voltage Range | Maximum Current | Best Current Sensitivity | SourceAdapt |
|---|---|---|---|---|---|
| PXIe-4140 | 4 | ±10 V | ±100 mA | 100 pA | No |
| PXIe-4141 | 4 | ±10 V | ±100 mA | 10 pA | Yes |
| PXIe-4142 | 4 | ±24 V | ±150 mA | 100 pA | No |
| PXIe-4144 | 4 | Low-voltage range | High-current configuration | Application dependent | No |
Recommended Related Products
- NI PXIe-4141 Source Measure Unit – recommended when greater low-current sensitivity and SourceAdapt support are required.
- NI PXIe-4142 Source Measure Unit – provides a wider ±24 V voltage range and up to ±150 mA.
- NI PXIe-4144 Source Measure Unit – suitable for lower-voltage applications requiring increased current capability.
- NI PXIe-6571 Digital Pattern Instrument – adds digital pattern generation and comparison for semiconductor test systems.
- NI PXI and PXI Express Modules – browse additional instrumentation for building an integrated test platform.
How to Select the Right PXI SMU
Choose the PXIe-4140 when an existing PXI system requires four channels of ±10 V, ±100 mA source and measurement capability with 100 pA sensitivity and high-speed sampling.
For a new system, compare the required voltage, current, low-current sensitivity, channel isolation, transient control and product lifecycle status. The PXIe-4141 may be preferable when SourceAdapt or improved current sensitivity is important, while the PXIe-4142 supports devices requiring a wider voltage range.
Why Choose the NI PXIe-4140?
The PXIe-4140 combines four SMUs, high-speed digitization, source sequencing and PXI synchronization in a single module. Its channel density and programmable measurement functions make it an effective replacement or expansion option for compatible semiconductor and automated test systems.
Frequently Asked Questions
How many SMU channels does the PXIe-4140 provide?
The PXIe-4140 provides four independently programmable source and measurement channels.
What are the maximum output ranges?
Each channel supports voltage sourcing and measurement from -10 V to +10 V and current sourcing and sinking from -100 mA to +100 mA.
What is the maximum measurement rate?
The maximum continuous measurement rate to the host is 600 kS/s per channel, excluding load-dependent settling time.
Does the PXIe-4140 support four-wire measurements?
Yes. Every channel supports four-wire remote sensing to compensate for voltage drops in cables and test fixtures.
Does the PXIe-4140 support SourceAdapt?
No. It provides preset slow, normal and fast transient response settings but does not include programmable SourceAdapt control-loop technology.
Are the four channels isolated from each other?
No. The channels are isolated from earth ground but share a common LO connection.
What is the PXIe-4140 part number?
The standard NI part number is 781742-01.
Is the PXIe-4140 still recommended for new designs?
No. NI classifies the PXIe-4140 as a mature product that is not recommended for new designs. It may still be appropriate for maintaining or expanding an installed system.
Request a Quote for the NI PXIe-4140
Contact us for current availability, lead time and project pricing for the NI PXIe-4140 four-channel Source Measure Unit. We can also help verify compatible PXI Express chassis, controllers, terminal blocks, cables and replacement SMU options for your test system.
