TIDA-01168: schematics

Hello,

thank you for your interest in the design. Let me answer your questions.

Q1: Any delay or a jitter in the control loop cause a phase margin erosion. The theory actually exceeds my qualification. Probably the best explanations and training on digital power I could ever get were from Biricha Power. You may find this link useful (although the presentation is dated):

https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/171/Presentation_5F002D005F00_Mr._5F00_Ali_5F00_Shirsavar.pdf

 I selected 1/10th of the control loop because the impact is minimal. \

Q2: This is correct. The LM5060 limits the current only in one direction as you described. Please also check if the input voltage range of the LM5060-Q1 fulfills your requirements. Clamping may not be sufficient due to the temperature drift of TVS and Zener diodes. 

Q3: I may not understand your question correctly. The main circuit breaker (transistors Q402-Q407) also protect the converter against the reverse polarity condition. The P-FET (Q400) circuitry allows the converter starting from the 12-V battery. The P-FET delivers just enough energy for the LM5170-Q1 so it opens the main circuit breaker. Without the P-FET, there would not be any energy to turn-on the 12-V circuit breaker when starting only from the 12-V rail. 

I hope this helps,

Best regards, 

Jiri

Hello.

Thank you for your reply.

Q1: I understand the design concept.

Thank you very much.

Q2: I understand.

Thank you very much.

Q3:Sorry.

I am not good at asking questions.

The following post is about E2E.

 https://e2e.ti.com/support/power-management/f/196/t/767327?tisearch=e2e-sitesearch&keymatch=LM5170

Even if the breaker MOS is off, the current between BRKS_BRKG will damage the IC. Therefore, I think we need additional circuitry. Is this understanding correct?

Is the following understanding correct?

To turn off the 12V circuit breaker, it is necessary to drop pin27 (FAULT) of the LM5170 to LOW, so this converter circuit cannot be turned off.

Best regards,

Hello ksma, 

I apologize for the late answer. I can confirm that my previous statement 

"The main circuit breaker (transistors Q402-Q407) also protect the converter against the reverse polarity condition."

was incorrect. I did not realize that a current can flow through the body diodes of the circuit breaker and this applies a negative voltage to BRKG and BRKS pins. 

The previous answer from Youhao Xi is correct. You need to implement the circuit as he proposed. Alternatively, you can use an external controller (such as LM5060-Q1. This reference design may be a good inspiration.

To your question:

"To turn off the 12V circuit breaker, it is necessary to drop pin27 (FAULT) of the LM5170 to LOW, so this converter circuit cannot be turned off."

Correct, you can not control the circuit breaker independently. The circuit breaker remains off (open circuit) in the shutdown and initialization mode. The circuit breaker is on (closed circuit) in the shutdown and power delivery mode. 

This means that you can switch the circuit breaker off either entering the initialization mode using the UVLO pin (1.5V < UVLO < 2.5V ) or entering the shutdown mode using the nFAULT pin (nFAULT < 1.25V).

You can't turn the circuit breaker off and keep the converter switching.  

Best regards, Jiri

Hello,Jiri_san

Thank you for the document.

This is very helpful.

Please tell me a little more.

Is it okay to realize that the TIDA-01168 circuit also basically supports ISO7637 or ISO16750 surge voltages, as shown in Figure 3 of TIDA-01167? The advantage of the TIDA-01167 circuit is that the converter can continue to operate during surges. It also has a reverse connection protection function. Is this understanding correct?

Best regards.