TPS65320-Q1-SMPS-CAL-TOOL: Modulable constant current source

Guido Jaeger

Part Number: TPS65320-Q1-SMPS-CAL-TOOL

Tool/software:

Hello,

I would like to realize a modulable constant current source. The current control was previously done with a linear regulator. This is to be changed in order to reduce waste heat. The operating voltage would be 3-12V, the current should be externally adjustable via a 0..10V source and the secondary should be 0/5mA to 3A.

My approach would be a switching regulator as a current source, a shunt in front of the consumer with a differential amplifier and thus an influence on the feedback from the switching regulator. The load would be one or more LEDs in series. The Modulation Speed via 0..10V should be as fast as possible.

Thanks for every Tip or Idea.

Greetings
calibra

4 months ago

0 Sarah Lao 4 months ago

TI__Genius 9897 points

Hi calibra,

I am redirecting your thread to LED experts for their insight.

Best Regards,
Sarah

0 Wyatt Keller 4 months ago

TI__Guru** 105760 points

Hello Calibra,

Is your application using a battery charger? Or are you looking for a switching converter with the type of regulation you outlined in order to drive the LED load?

Sincerely,

Wyatt Keller

0 Guido Jaeger 4 months ago in reply to Wyatt Keller

Prodigy 20 points

Hello Wyatt,

the Circuit should drive different Types of Laserdiodes. Threshold Voltages 2.1 to 4.5V . The PCB will be powered with 12V DC.
In older Circuits i used a StepDown to reduce the Supply Voltage to Diode Voltage and a Linear REgulator to modulate the Current .

Problem is the Heat Lost. I hope to replace the Linear Regulator with a SMPS in continous current mode with the possibility to modulate it.

0 Wyatt Keller 4 months ago in reply to Guido Jaeger

TI__Guru** 105760 points

Hello Guido,

Okay, it looks like you may need a medium voltage buck converter with some constant current control to drive them. Let me check with our buck converter team if they have what you need.

Sincerely,

Wyatt Keller

0 Guido Jaeger 4 months ago in reply to Wyatt Keller

Prodigy 20 points

Hello Wyatt,

thanks for that. I think the biggest Problem is to modulate the current fast enough. Normal Laserdiode Drivers are modulted with about 100KHz.

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TPS65320-Q1-SMPS-CAL-TOOL: Modulable constant current source