Off-the-shelf D.C. power supply units (PSU) are frequently used for low voltage (12V, 24V, 48V) EMC testing of automotive electronics and other electronics. With rare and pricey exceptions these PSUs suffer from poor transient responses and high electrical noise levels.
Transient Response
When a high current fast pulse (e.g., 20A in 200 μSec) is taken from the output of a PSU there will be a small dip in the output voltage (1 to 1.5V or more) until the internal control circuit responds. PSUs with good transient responses are rare and pricey and tend to be available only in high end PSUs.
Our LVTGO fixes this with a controlled output stage that offers stepped load response time better than 10 μSec, typically 3-5 μSec, on the microCUT models and response times in the order of 500 μSec on standard units. The LVTGO fitted to the output of a slow response power supply with sufficient headroom offers fast output response times. An optional internal integrated power supply of the LVTGO also offers fast response times and minimizing power loss.
Noise Levels
The majority of D.C. power supply units available are of the switched-mode converter type chosen for efficiency, size and cost. These output types inject noise pulses at their output in the order of a few hundred KHz when the switching occurs inside the unit.
The LVTGO hardware cleans up the switched-mode PSU noise by feeding the noisy PSU to the LVTGO hardware with sufficient headroom. LVTGOs with integrated PSUs offer the best of both worlds by minimizing power loss at the same time as achieving all the capabilities of the test equipment range.
Remote Sense
In some test setups, the wires between the LVTGO and the device under test (DUT) may not be adequately rated or are particularily long. In this case, especially with high currents, the wires between the LVT and the DUT may drop some voltage. The remote sense capability of the LVT fixes this by dramatically minimizing the voltage drop (and usually eliminating it) at the load end of the DUT.
LVTGO Capability
The LVTGO has maximum output options of 20V, 30V, 60V and 80V for testing 12V, 24V, 27V and 48V systems as well as a large library for testing for robustness and compliance to standards. More details here.