LM7310: Inquiry when using 21.6~26.4 V, 0.5 A for this product.

Hi S.Y. Lee,

This product is not intended for the industrial applications hence the maximum voltage rating is less. Can you share some of your recommendations so that based on them, I will recommend you some other parts. For 24V application, we will have to go with eFuse (similar to load switches but more protection features)  

Since you were considering this part, I will recommend similar parts (parts with reverse current blocking). Here is a list. https://www.ti.com/power-management/power-switches/efuse-hotswap-controllers/products.html#339=Internal&1498=Catalog&238max=24%3B100&

TPS26xx will provide reverse current blocking and can handle your required voltage. 

Best Regards,
Arush 

Thank you for reply.

The purpose is to block the unstable input of the 24 V, 0.2 A level power applied to the controller.
Voltage range: 20~26 V
Function: UVLO, OVP
Priority: 1. Unit price, 2. Size, 3. Temperature

Currently, I'm designing the circuit by selecting LM74502 as the second best, but a little dissatisfied that it is not small and the unit price is not cheap if an external FET is included.
The TPS2662 series, which is more expensive than this LM74502+FET, was the third priority, and the TPS2661 series has high internal resistance and is judged to be unsuitable for power supply. (I'm working with LM74502, but still reviewing whether TPS2662 is better due to its suitability for 24 V applications.)

If there is a cheaper or better product for implementing UVLO and OVP, please recommend it.

S.Y.Lee

Hi S.Y.Lee,

I am adding my colleague who is more handles these higher voltage eFuses. I am not sure if we have any such part with this >24V part with RCB and is very cheap.

Can you tell me the end application. This will help in determining the future part definition. 

Best Regards,
Arush

Hello SY Lee,

TPS2662 is a better option to go for as per your requirement for 24V,0.2A with reverse current blocking.

How much minimum reverse current blocking you are expecting?

Coming to pricing, please send me a mail regarding number of units requirement and your expected pricing. I will forward the concerned marketing team.

Thanks

Amrit 

Since I judged that RCP would not be necessary in the end, I think I'll use the existing LM74502, which prioritizes unit price.

Since the output stages are all separated into isolated DC/DC CONV and the circuit is based on the premise that overvoltage and reverse voltage are protected with SPD+PPTC+TVS, I think only OVP+UVLO is sufficient. However, the order is ambiguous as to whether the blocking should be done after the CM filter+DM filter or before it.

S.Y.Lee

If the DC/DC CONV, which is the output part on the power side, does not malfunction, I think there will be almost no reverse current because the capacity on the capacitor side is not large. Since the current consumption is also not large, reverse current was not considered during the design.

Currently, there are about 10 units, and it is being developed at a level where it is not possible to predict how many units will be produced after that. If I am really lucky and produce enough units to be able to purchase in bulk, I will have to contact you separately.

When I first started developing, I only looked at the unit price listed on the site and made decisions, but I will review TPS2662 again when creating the BOM.

S.Y.Lee

Hello.

My reply is a bit late.
Based on the product that converts from 24 V to 5 V,
I think it means 'Reflected Ripple Current'. Is that right? The current product is 15 mA typ. and there is also a 7.5 mA typ. as an alternative, but if I search, see that there are more products that do not have it written.

S.Y.Lee

Hello Lee,

Yes, you are correct. 

I have an additional inquiry.

If it is an LM74502 product, it does not have a reverse current blocking function, so it is irrelevant.

In the case of TPS2662, the threshold for reverse protection comparator, which is the reverse current blocking standard, is 15 mV, so I is expected to be I = 0.478/0.015 = 31.3 mA. In this case, can I assume that the blocking operation will not occur forever due to the Reflected Ripple Current generated in the DC-DC CONV?

S.Y.Lee

Hello SYLee

Device will block the reverse current when it's more than 31.3 mA.