LV5144: How to use this IC

masao hirai

Part Number: LV5144
Other Parts Discussed in Thread: LM70860, LM5146, LM5145

Tool/software:

(1)Can LV5144 be used in a power supply with the following specifications: input voltage 53V～ 58V, output voltage 51V, 5.6A?

(2)This IC does not operate in sync with an external signal. In that case, how should I handle "7p" and "8p"?

(3)Should I leave "15p" open?

(4)Please provide me with some example circuits using this IC.

11 days ago

0 Timothy Hegarty 10 days ago

TI__Guru 72782 points

Hi Hirai-san,

1. Yes, the LV5144 is feasible, but why not use a converter with integrated FETs, e.g. LM70860?

2. It accepts external SYNC signal.

3. The NC pins can be connected to GND for better heat spreading.

4. See the apps examples in the data sheet - also refer to the LM5145 and LM5146 files.

Regards,

Tim

+1 masao hirai 10 days ago

Prodigy 10 points

Hi Tim

Thank you for your quick response.

There seems to have been a slight misunderstanding.

When not using external synchronization, that is, when operating with internal oscillation, should "SYNCIN" be pulled down or pulled up with a resistor?

Is "SYNCOUT" okay to be OPEN?

0 Timothy Hegarty 10 days ago in reply to masao hirai

TI__Guru 72782 points

Yes, SYNCOUT should be open if not used.

And there is an internal 20kΩ resistor pulldown on SYNCIN, so leave it open or tied to GND for diode emulation mode. Connect to VCC for FPWM mode.

0 masao hirai 10 days ago in reply to Timothy Hegarty

Prodigy 10 points

Thank you very much. I understand well. Again,

0 Timothy Hegarty 10 days ago in reply to masao hirai

TI__Guru 72782 points

Great, thank you.

0 masao hirai 8 hours ago in reply to Timothy Hegarty

Prodigy 10 points

Hi Tim

Thank you for your advice so far.

The experiment is proceeding without any problems so far.

There is one additional thing I would like to check: the capacitor connected to the "SS/TRK" pin.

I want to set the soft start to about 1 second, so I am connecting a 10uF capacitor.

How many uF can be connected to this pin?

0 Timothy Hegarty 8 hours ago in reply to masao hirai

TI__Guru 72782 points

Not sure of there's any limit, but 1 second is the highest I've heard for that. Why so long?

0 masao hirai 1 hour ago in reply to Timothy Hegarty

Prodigy 10 points

We are operating it as a constant current power supply. I think it is also related to the value of the output smoothing capacitor, but it is to suppress the overshoot of the output current at startup. In reality, I think it will be about 0.5 seconds.

Power management

Power management forum

LV5144: How to use this IC