PXIe-4150 Theory of Operation
- Updated2025-10-22
- 2 minute(s) read
PXIe-4150 Theory of Operation
The PXIe-4150 combines a digital control loop architecture with precision electronics to constant voltage (CV) or constant current (CC) sources with built-in measurement of voltage and current output.
One significant advantage of SourceAdapt is the ability to make precise adjustments to the control loop to customize the transient response to any load, so you can achieve an ideal transient response with minimum rise times and no overshoots or oscillations.
The PXIe-4150 can operate in either CV mode or CC mode.
- In CV mode, the device acts as a precision voltage source that holds the voltage across the selected voltage sense points constant with respect to load changes as long as load current is below the programmed current limit.
- In CC mode, the device acts as a precision current source that holds the current across the load constant with respect to load changes as long as load voltage is below the programmed voltage limit.
A measurement circuit on the PXIe-4150 can simultaneously read the voltage and current values using two integrating analog-to-digital converters. Voltage is measured differentially between the HI and LO terminals (local sense) or between the Sense HI and Sense LO terminals (remote sense) based on the programmed voltage sense location. Remote sense is used to compensate for voltage drop that results from resistance in cables, connectors and switches. Current is measured using shunt resistors in series with the LO terminal.
There are several protection mechanisms built into the PXIe-4150 that guard against common faults.
The PXIe-4150 continuously monitors voltage between HI and LO or HI Sense and LO Sense and protects against overvoltage faults. If an excessive voltage is detected, the overvoltage protection (OVP) circuit opens the Output Disconnect switch to protect the PXIe-4150 from excessive over-voltage.
In the event the Sense terminals are left disconnected during remote sense operation, the 100 kΩ open-sense protection resistors provide a voltage feedback path to prevent the output voltage from saturating to a large voltage level.
The output terminals of the PXIe-4150 are electrically isolated from chassis ground through a 150 V DC, Category I isolation barrier. This allows any channel terminal to float ±150 V DC with respect to chassis ground.
The PXIe-4150 includes flexible source and measurement units that enable multiple programming modes and timing options:
You can use hardware triggers in all modes to control operation of the source and measure units with other channels or devices in the system. The measurement engine operation can operate in waveform acquisition mode and can be decoupled from the sequence engine. Refer to Sourcing Voltage and Current for more information about triggerable events in each programming mode.
Related Information
- Sourcing Voltage and Current
The PXIe-4150 can perform operations to source and measure voltage and current. In order to perform these operations, use the NI-DCPower driver to configure software settings and execute operations.