Agilent U8030 Series 375 Watt Triple-output Power Supply
The Agilent U8030 series are compact DC power supply that provide excellent load regulation and clean output noise for continued stability, and offer a total output of 375 W. These power supplies have three outputs—one fixed output and two variable outputs—that can be controlled individually or simultaneously. Here are a few tips on how to optimize the capability of these multiple-output power supplies:
Tip 1: Automate your test with output sequencing function
The Agilent U8030 Series DC power supply comes with output sequencing feature. You can store three settings and recall these settings in sequence either as single or loop operation from the front panel. This feature for example is very convenient if you would like to perform a power cycle test on embedded systems without using a computer.
By storing three different settings into the U8030 Series power supply, you can configure the power supply to continuously cycle the power of the embedded system. Furthermore, with two programmable output channels on the U8030 Series, you can test two embedded systems simultaneously.
Tip 2: Connect the outputs in parallel or in series to achieve higher voltage or current
Connecting two or more power supplies or output channels in series (Figure 1*) provides higher voltages, but observes these precautions:
• Never exceed the floating voltage rating of any of the supplies.
• Never subject any of the power supplies to negative voltages.
Connecting two or more power supplies or output channels in parallel (Figure 2) provides higher currents, but again, observes these precautions:
• One unit must operate in constant voltage (CV) mode and the other(s) in constant current (CC) mode.
• The output load must draw enough current to keep the CC unit(s) in CC mode.
Tip 3: Eliminate noise from low level measurements
Noise in low-level measurements can come from a number of different sources, and it’s easier to eliminate noise than to filter it.
Check these noise sources:
I. Power supply
Starting with a low-noise supply is naturally a great way to keep noise out of your measurements. Linear power supplies have lower common-mode noise currents and generally operate at low frequency. However, you can use switch-mode supplies successfully if their specifications include a low common-mode current. As a rule of thumb, common-mode current over 20-30 mA is likely to cause trouble.
II. DUT to power supply connections
Minimize conducted noise by eliminating ground loops. Minimize radiated pick-up (both electric and magnetic) by using twisted shielded conductors for the output and remote sense leads. To make sure the shield doesn’t carry current, connect the shield to ground at one end only, preferably the single-point ground on the supply (Figure 3).
III. Current variations to the DUT
Rapid changes in the DUT’s current demand cause voltage spikes. To prevent this, add a bypass capacitor close to the load. The capacitor should have low impedance at the highest testing frequencies. Avoid imbalances in load lead inductance; direct connections to the DUT, such as twisted shielded pair, are your best bet.
For more information visit: www.agilent.com/find/u8030
* For all the figures please refer to article in the February issue, in print or digital format, by subscribing here