Looking for a DC-DC converter with external PWM signal (not for sync)

Avihai O

Other Parts Discussed in Thread: LM5114, LM3478

Hi,

I'm looking for a DC-DC converter/controller which can receive an external PWM instead of the internal one, not for synchronisation purpose.

The wanted topology is boost, buck-boost or flyback.

The input voltage is 3-5V and the output current is under 500mA.

I'd like to have an option in which the PWM signal is external, and when it's off, the output voltage is zero.

Please advise.

Thanks

over 7 years ago

0 Youhao Xi over 7 years ago

TI__Guru* 78340 points

What you need is a MOSFET driver but not a PWM converter/controller. For your boost, buck-boost or flyback topology, you need a low side driver. An example is the LM5114. If you need further assistance, please start a new post with the LM5114 in the title and you will receive the support form an expert of MOSFET driver ICs.

0 Avihai O over 7 years ago in reply to Youhao Xi

Prodigy 170 points

Hi,

Thanks for the answer.

After some research, I understand that what I actually need is voltage-dimming using PWM, something like a constant-voltage LED driver (which I'm not sure that exists).

0 Avihai O over 7 years ago in reply to Youhao Xi

Prodigy 170 points

Hi,

In fact, an example of my need is Linear's LT1619 PWM controller which has option to use a clock signal as an enable.

I'd like to know if there's something similar from TI.

Thanks

0 Youhao Xi over 7 years ago in reply to Avihai O

TI__Guru* 78340 points

You may consider the LM3478/88 which can control via the clock pin (FA/SYNC/SD). You may also check TI product under LED Lighting folder (link below).

0 Avihai O over 7 years ago in reply to Youhao Xi

Prodigy 170 points

Thanks!
Exactly what I needed.
For my future searches, does this kind of enable have special know keywords?

Power management

Power management forum

Looking for a DC-DC converter with external PWM signal (not for sync)