Keithley Instruments, Inc. has published a poster to help engineers and researchers utilize techniques that will enhance the performance of their power supplies in applications in research, design, and high-speed production test. To download a free copy of the “Maximize the Performance of Your Power Supplies” poster, visit: http://www.ggcomm.com/Keithley/PwrSupplyPoster_LP.htm.
Although most technicians, scientists, and engineers believe they have a good understanding of power supplies because they are single-function DC devices, power supplies are still sophisticated instruments. Keithley’s illustrated poster describes five different methods for enhancing power supply performance:
- Ensure that the programmed voltage is accurately delivered to the load: This section outlines how remote sensing techniques can improve voltage sourcing accuracy.
- Extend the range of your outputs using a multi-channel power supply: Multi-channel power supplies with isolated channels allow combining the channels in either series or parallel to double the output voltage or current. They also allow connecting two channels to provide a positive output and a negative output to power bipolar circuits. Some supplies are even capable of having both channels change simultaneously (track) for testing a circuit over its voltage operating range.
- Accurately measure load currents: Do you need to measure the current that the load is drawing? Power supplies with good readback accuracy and high resolution can be used to determine load currents directly, with no need to add a sense resistor in line and a digital multimeter (DMM).
- Safely power up and power down circuits in the proper sequence: When powering digital board designs with circuits that operate at different voltages, powering the circuits up and down in the correct order is essential to avoid stressing and damaging low-voltage circuits. Multi-channel power supplies that allow independent channel control speed and simplify this process.
- Minimize noise when powering low power and sensitive circuits: The use of shielded cables is essential to keeping external environmental noise out of test circuits because even small amounts of noise current can create a large error voltage in a high impedance circuit. Ensuring the circuit is grounded at only one point to eliminate ground currents that can create error voltages in conducting pathways is also critical to minimizing noise interference.