LDD-Feature: Feedforward Control

Feedforward control feature for LDD-130x laser diode drivers


Meerstetter Engineering's paid feature feedforward control for laser diode drivers LDD-1301 and LDD-1303 helps in pulsed and modulated applications where a very fast rise time (<100 µs) is required. Thanks to feedforward control based on an automatically recorded laser diode characteristic, users of the LDD-130x laser diode drivers obtain significantly more dynamic control behaviour of the transient target currents.

Find out more about the feature feedforward control this compendium article or in the LDD-130x User Manual, chapter "Feedforward control (PDF)".

When purchasing a new laser diode driver LDD-130x from Meerstetter Engineering (or after loading FW v2.21 into an older one), the feature is free for trial for the first 150 operating hours. The feature can then be permanently activated by loading a licence key onto the device. Licenses can be obtained from Meerstetter Engineering by leaving a comment in the RFQ or order for a laser diode driver (LDD-1301 or LDD-1303), or by contacting the sales team directly. Please be sure to include the following information in the order/RFQ when ordering a paid feature: the serial number, laser diode driver type and, if applicable, licence keys of already purchased features for the corresponding device (S/N _____, LDD-130X, Feature _____).

Please note: The LDD-130x Service Software used to configure and monitor your laser diode driver is free of charge. Only certain advanced features such as
Feedforward control require a license after the free trial period.

Read more about license handling and prices below under the tab "Price / License".

Detailed Description

Feedforward control is an advanced feature designed to enhance the precision and speed of Meerstetter laser diode drivers LDD-130x. Unlike traditional PID control, which relies on iterative adjustments, feedforward control uses a predictive approach based on a pre-characterized model of the load. This allows the system to achieve the target current almost instantaneously, making it ideal for applications with high dynamic requirements.

One of the key advantages of feedforward control is its ability to approach the target current in the first control cycle and achieve it almost immediately. By using predictive control, stable performance is ensured without the need for expensive drivers capable of picosecond control. This combination of speed and precision makes feedforward control particularly suitable for demanding applications where rapid and accurate control is crucial.

The technical implementation of feedforward control is based on a model-based control that uses a mathematical model of the load to directly calculate and set the required output value. In many applications, feedforward control is combined with PID control to quickly bring the system close to the setpoint, while PID compensates for small deviations. Optimized parameters such as gain, slope limit, and PID options can be configured to prevent overshoot and ensure smooth operation.

Feedforward control is particularly beneficial in pulsed laser applications and scenarios requiring very fast rise times, such as material processing and spectroscopy. The combination of feedforward control and PID control allows the target value to be reached up to ten times faster than with PID control alone.

In summary, Meerstetter Engineering’s feedforward control feature sets new standards in laser diode driver technology, offering unmatched speed and precision for demanding applications.

More information about the feature feedforward control can be found in this compendium article or in the LDD-130x User Manual, chapter "Feedforward control (PDF)".

Price model - License handling

  • By purchasing a new laser diode driver LDD-1301 or LDD-1303 from Meerstetter Engineering (or after loading FW v2.21 into an older one), all features are free for trial the first 150 operating hours.
  • If you need more testing hours, ask us for a prolonged trial license.
  • After trial period, the feature can be permanently unlocked by loading a license key into the device.
  • Licenses can be obtained from Meerstetter Engineering by leaving a comment in the RFQ or order for a laser diode driver LDD-1301 or LDD-1303, or by contacting the sales team directly.
  • New devices ordered with specific feature(s): The license is already installed on new laser diode drivers.
  • License ordered for an existing device at the customer: The license is an alphanumeric string, that is sent by e-mail and must be copied into the “Apply license” field (in the LDD-130x Service Software: Tab “Advanced” -> “Feature License”) for each device separately. Pay close attention to the license status and if the expected feature is enabled after loading the license (on the right side in the “Feature License” tab). If the license does not match the device, it will not work.

Be aware, that the license is only valid for a specific device. Therefore, please make sure you provide the correct information: the serial number, laser diode driver type and, if applicable, licence keys of already purchased features for the corresponding device (S/N _____, LDD-130X, Feature _____).

Technical data

Supported Devices Laser diode drivers LDD-1301 and LDD-1303.
Price See this optional features price table (PDF)

The feedforward control feature requires a software licence and a load characterization of the laser diode in CW mode.