LM74610-Q1: Voltage drop due to T0/T1 cycling

Gary Routledge

Part Number: LM74610-Q1
Other Parts Discussed in Thread: LM74700-Q1, LM74700-EP, LM7480-Q1, LM7481-Q1

We are using LM74610 in a power supply OR-ing application as shown in Figure 21 of the datasheet. However, due to the T0/T1 cycling as shown in Figure 9 of the datasheet we are not getting a constant voltage level which we need. This is not a battery application, it is used on a backplane with redundancy power supplies.

Please can you tell me if it is possible to use this part with constant power flow or if you have an alternative part that is more suitable to my application?

Oring Issue.docx

over 1 year ago

0 Praveen GD over 1 year ago

TI__Guru 57737 points

Hi Gary,

Thanks for reaching out to us. Let me review your query and get back to you by tomorrow.

0 Gary Routledge over 1 year ago in reply to Praveen GD

Prodigy 40 points

Hi, please can you supply an update, this is urgent. Thanks!

0 Praveen GD over 1 year ago in reply to Gary Routledge

TI__Guru 57737 points

Hi Gary,

Using LM74610-Q1 there is no way to eliminate the ripple on Vout as the gate turn OFF is required for the device internal charge pump to charge using the FET body diode drop.

I would recommend you to have a look at LM74700-Q1. This device has a GND reference and hence does not need the Gate to turn OFF the FET ocassionally. So, there would be no ripple on the output voltage.

0 Gary Routledge over 1 year ago in reply to Praveen GD

Prodigy 40 points

Hi,

Availability of this component is very limited with all the major distributors. Does TI have stock available?

What about LM74700-EP, this part seems to be available with major distributors but i am not sure if it is AEC-100 qualified.

0 Praveen GD over 1 year ago in reply to Gary Routledge

TI__Guru 57737 points

Hi Gary,

Unfortunately, I cannot comment on the component availability as it is very dynamic. LM74700-EP is not AEC-100 qualified.

You can have a look at other Ideal diode controllers like LM7480-Q1, LM7472x-Q1 and use them in Ideal Diode only configuration as shown below.

0 Gary Routledge over 1 year ago in reply to Praveen GD

Prodigy 40 points

Hi,

I need a solution for OR-ing circuit, redundant power supply for various voltage ratings between 3.3V - 28V and AEC-100 qualified.

LM7480-Q1 is not showing stock anywhere but LM7481-Q1 is showing healthy stock levels. What is the difference between LM7480-Q1 and LM7481-Q1?

0 Praveen GD over 1 year ago in reply to Gary Routledge

TI__Guru 57737 points

Hi,

LM7481-Q1 has higher 'DGATE drive strength' and 'charge pump source current' when compared to that of LM7480-Q1. This will help LM7481-Q1 to rectify AC superimposed signal of higher frequency as explained in Ideal Diode Controllers for Active Rectification of AC Voltage Ripple Application note.

All the other features and functionalities of LM7481-Q1 and LM7480-Q1 are same. For ORing application, there will be no difference in performance if you use LM7481-Q1 or LM7480-Q1

Power management

Power management forum

LM74610-Q1: Voltage drop due to T0/T1 cycling