How to avoid current overshoot when the laser is powered on?

DC power supplies typically operate in two modes: Constant Voltage (CV) and Constant Current (CC), each controlled by its own internal loop. Most power supplies on the market today prioritize the CV loop, which can limit their performance in applications requiring precise current control. While this approach may allow for faster voltage rise, it often leads to current overshoot, making it unsuitable for sensitive testing scenarios.

The IT6100B high-speed, high-precision programmable DC power supply series introduces a groundbreaking CC/CV priority concept, giving users more flexibility and control. This innovation allows users to set the priority of either the CC or CV loop through the power menu interface, enabling advanced applications without the need for additional hardware. This not only improves test accuracy but also reduces overall costs significantly.

In current priority mode, the CC loop is given higher responsiveness, ensuring that once the current reaches the set value, it is quickly controlled to prevent overshoot. This results in a fast current rise time with minimal or no overshoot, providing clean and stable output performance. This feature is especially important in applications like laser testing, where even small current fluctuations can cause damage.

Current priority mode characteristics at startup

Case Study: Laser Testing

Traditional power supplies often have slower CC loops and lower priority, which makes it difficult to detect and suppress current overshoots quickly. In conventional laser testing, the oscilloscope would show significant current overshoots during startup. However, with the IT6100B series, users can set the CC loop to high priority, allowing the power supply to enter constant current mode rapidly and avoid any overshoot, thus protecting the laser device.

Voltage priority characteristics at startup

The IT6100B series provides excellent current control across a wide range of starting currents, from milliamperes to amperes. Whether it's 5A, 2.5A, or 250mA, the power supply ensures no overshoot, maintaining clean and stable output waveforms. This level of precision is essential for high-stakes testing environments such as aerospace, where reliability is critical.

With a power range from 86W to 1200W, the IT6100B series offers ultra-fast voltage rise times, up to 500μs under full load, and resolution as fine as 0.1mV and 0.01mA. Its advanced waveform control ensures both speed and stability, making it ideal for high-precision testing. The built-in USB, RS232, and GPIB interfaces, along with panel-based list programming, provide flexibility and ease of use, supporting a wide variety of test scenarios.