Power protection for Automotive electronics

Hi Sakthivel,

Our ESD/Surge protection devices can protect from transient events, however we don't have any devices that can withstand 15 A of current for 12/24 V battery systems.

It sounds like you're looking for a power switch, something like the LM7480-Q1, however I'll loop in the correct experts to comment.

Regards,

Sebastian 

Hi Sebastian,

we found Automotive 12- and 24-V Battery Input Protection IC "LM5060" which compliance both ISO 7637-2, ISO 16750-2 but the part and FETs used are not available, could you please provide alternate part for LM5060?  if possible please share it with over current protection.

Thanks,
Sakthivel 

Hello Rakesh,

The part needs mere room it seems, by having too many diodes , FET and bulk capacitors and few components are not available in stock, Is there any single Chip solution with few FETS and bulk capacitors for Automotive input protection systems? 

Our requirement:

1, Input Voltage : 9 to 36 V.

2, Current : 15A if 9V input and 4.5A if 36 V input.

3, Temperature range : -30 to 70 Deg celcius

Hi Rakesh,

This is LM5060 based protection circuit, "https://www.ti.com/lit/ug/tiduc41/tiduc41.pdf"

1, why do we need two FETs ? Can we skip the NPN transistor part ?

2, Can we skip the Enable circuit part also?

Thanks,  

Hi Rakesh,

please find the simple Block diagram of our Automotive product, as per our understanding the power protection should be compliance to ISO 7637-2, ISO 16750-2, which includes load dump test, Reverse voltage protection, and Super imposition of AC voltage test etc..

1, Does our system requires all those tests?

2,  Does LM5060 /LM74800-Q1 compliance to Super imposition of AC voltage test?

3,- Could you please suggest any battery input protection methods for our system?

Thanks

Hi Preveen,

Thanks for your support,

Please find the simple power flow diagram of our product, kindly review it, and let us know if there will be any issue by connecting "LM7480X-Q1" and "LM5175-Q1."

we planned to use the following power protection ICs based on the availability "LM7480X-Q1, LM7481X-Q1"

Thanks,
Sakthivel

Hi Praveen,

In the Lm7840 datasheet, we are able to see only 2V peak to peak AC superimposition suppression; is it possible, with the LM7840 or LM7841, to superimpose AC up to 10V peak to peak as per the standard of ISO 16750-2?

https://www.compel.ru/wordpress/wp-content/uploads/2017/05/ISO-16750-22010E-.pdf

Thanks

Sakthivel

Hi Praveen,

What is the maximum output current can be driven from LM7480x ? 

Output current range specified in the table -> 2A for 24V load, Is this only for example ?  

Our product requires 150W of power so roughly 6A required if input voltage in24V will LM740x capable for handling such loads?

Thanks,
Sakthivel

Hi Praveen,

If the part "LM7480-Q1" is used in the common source configuration for 200V load dump suppression as mentioned below,

Will it be capable of rectifying the superimposed AC voltage for a 24 V system? with 6V peak-to-peak?

In the design parameter of the 24V unsuppressed load dump protection table, we don't find information regarding superimposed AC voltage.

If the part is not suitable, how do we achieve the power protection with 200 V of unsuppressed load dump, reverse power protection, and superimposition of AC voltage?

Thanks,

Sakthivel

Hi Praveen,

Please suggest any 200V Hgate FET parts,

Thanks,
Sakthivel

Hi Praveen,

As per our understanding, we are able to protect a 200V load dump with the common source configuration, so we plan to proceed with the CS configuration. Could you please ensure that with the CS configuration we can achieve the listed protection features?

1, Rectifying superimposition of AC 6V peak to peak with upto 200KHz frequency?

 -> we dont find an appropiate data for LM7480 can rectify 200Khz AC in Common source configuration.

2, What could be the maximum reverse voltage can be blocked by LM7480 in Common source configuration,

Thanks,

Sakthivel

Hi Praveen,

We can find the AC super imposed test data only for Common Drain configuration (12V system) in the table 10.1 (LM7480-Q1 data sheet)  

As mentioned previously, our requirement is that our project should withstand 200 volt load dump test hence we need to choose common source configuration. for 24V battery system, but in datasheet the 24V domain specification table does not have any data regarding AC superimposition 

1, Could you please ensure the the part with common source configuration can rectify the superimposed AC voltage?

         If so please provide us the till what frequency and magnitude rectification is possible. 

Hi Praveen,

Based on our understanding, we are going to draft the schematics as shown in Figure , with the parts mentioned below, Our expectation of the part's behavior is to withstand the following conditions, kindly review and give your feed back.

1. As per the test, our device must withstand 200 V load dump pulses for duration of 350 ms for 5 cycles.

2. The part should rectify the AC superimposed voltage with a magnitude of 6 volts peak to peak at a frequency of 200 kHz.

3, The part should block the reverse voltage of -35V.

4, Output should be clamped to 37V if input is 200V peak pulse.

Thanks,

Sakthivel

Hi Praveen,

Thanks or your support,

As per our understanding, the TVS diodes are used to clamp the input voltage; if the input exceeds 65, it will clamp, and since it is bidirectional, if reverse voltage occurs, it will direct it to the battery and protect the circuit. Please ensure our understanding is correct.

1. We chose the TVS diodes and wired them together as shown in the figure: D4 - "TPSMD36A"; D3 - "SLD8S36A" (D3 and D4 have a clamping voltage of 53 volts).

If there is an input load dump (202V peak pulse voltage), the D3 TVS diode clamps it to 53V, and if the reverse voltage exceeds -53V, the D4 diode clamps it to -54V, and the LM7480-Q1 protects the circuit until the reverse voltage is -53V. Is our interpretation correct? If this point is correct, we don't need a 200-volt-rated MOSFET for HGATE, right? The total gate charge of currently available 200V-rated FETS is 30nC, and only a very low frequency of AC super imposition can be rectified. For that only, we decided to go with 100V-rated FETS,

2. For example, if the total gate charge of the FET is 25 nC, then the maximum frequency of AC superimposition that can be rectified by our part is 108 kHz if the charge pump current is 2.7 mA. Is this understanding correct?

Thanks,
Sakthivel

Hi Praveen,

Is there any update on the below request?

Hi Praveen,

1, Can i connect the diodes as shown in the below image for withstanding 200V load dump for the duration of 400mS ?

2, Can we use the  "LM74810-Q1" for 200V load dump case? in front of the diode structure mentioned in the image ?

                Because nowhere in LM74810-Q1 data sheet it is mentioned that we can use the part for 200V un suppressed load dump protection.

3, Does all other functionalities of LM74810-Q1 is similar to LM7480 ? 

Hi Praveen,

Is there any update?