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Power Management ICs Forum Discussions

Mark_Evens
Level 1
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Hello,

I am designing a 325V nominal DC to 72V DC convertor using ICE1HS01G-1. But don't get any solution from the datasheet or demo board documentation.  So what is the way for feedback circuit design?

Screenshot from 2022-05-10 18-06-11.png

Thank in advance

Mark

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SC
Moderator
Moderator 10 likes received 25 replies posted 10 solutions authored
Moderator

Hi,

Thanks for posting at the Infineon community.

Regarding TL431 feedback circuit design, we recommend you follow the below steps to estimate the feedback circuit parameters.

1. For RB1 (Refer Part Datasheet ICE1HS01G-1) where RB1 = RLED, MAX

SPCH_0-1652266915876.png

VZ = VO

Rpull-up value Refer to the datasheet.SPCH_1-1652267016516.png

2. RB2 Refer to TL431 datasheet and follow the selection guide (Preferred value 1k to allow min required bias current)

3. ROS1 and ROS2 are feedback divider values choose to set the TL431 Reference value from the output voltage

4. CC1 is DNP in the application design guide

5. For RC1 = R2

SPCH_2-1652267132953.pngSPCH_3-1652267144522.png

In above formula R1=ROS1

FC = Cross over frequency
FZ = Zero Frequency
FP = High Frequency Pole 

5. For CC2 = C1

SPCH_4-1652267220715.png

However, after the estimation of feedback design values, better to sweep the response for different load conditions.

Thanks,

SPCH

 

 

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Mark_Evens
Level 1
5 replies posted 10 sign-ins 5 sign-ins
Level 1

I am asking is any explanation on this circuit. I appreciate any help.

Thank you

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SC
Moderator
Moderator 10 likes received 25 replies posted 10 solutions authored
Moderator

Hi,

Thanks for posting at the Infineon community.

Regarding TL431 feedback circuit design, we recommend you follow the below steps to estimate the feedback circuit parameters.

1. For RB1 (Refer Part Datasheet ICE1HS01G-1) where RB1 = RLED, MAX

SPCH_0-1652266915876.png

VZ = VO

Rpull-up value Refer to the datasheet.SPCH_1-1652267016516.png

2. RB2 Refer to TL431 datasheet and follow the selection guide (Preferred value 1k to allow min required bias current)

3. ROS1 and ROS2 are feedback divider values choose to set the TL431 Reference value from the output voltage

4. CC1 is DNP in the application design guide

5. For RC1 = R2

SPCH_2-1652267132953.pngSPCH_3-1652267144522.png

In above formula R1=ROS1

FC = Cross over frequency
FZ = Zero Frequency
FP = High Frequency Pole 

5. For CC2 = C1

SPCH_4-1652267220715.png

However, after the estimation of feedback design values, better to sweep the response for different load conditions.

Thanks,

SPCH

 

 

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Mark_Evens
Level 1
5 replies posted 10 sign-ins 5 sign-ins
Level 1

1- Here RB1 written as RLED,max so it is some type of LED or it's simple resistor ? why it's name is RLED?
2- In datasheet I am not able to find Rf value will you highlight something.
3- VZ=VO=72V it is ok or I am getting wrong ?

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SC
Moderator
Moderator 10 likes received 25 replies posted 10 solutions authored
Moderator

Hi,

1- Here RB1 is written as RLED, max so it is some type of LED, or is it a simple resistor? why its name is RLED?

It is a simple Resistor. For your information, a light-emitting diode (LED) is an integral part of an Optocoupler at the input side which is the reason we named as RLED.

2- In the datasheet I am not able to find the Rf value will you highlight something.

I did not understand Rf Ref. where it is mentioned.

If you are looking for a pull-up resistance value, it was mentioned in datasheet page No. 15, Section 4.3.6 (Typical value 20kΩ)


3- VZ=VO=72V it is ok or I am getting wrong?

Yes, you are correct VZ = VO=72V.

The simulation tool as shown in the below link may help to tune the feedback circuit accordingly.

https://www.infineon.com/cms/en/product/power/ac-dc-power-conversion/ac-dc-pwm-pfc-controller/llc-re...

Thanks,

SPCH

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Mark_Evens
Level 1
5 replies posted 10 sign-ins 5 sign-ins
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1 - FZ = Resonant frequency?
And I don't know what is the cross over or high-frequency pole is.
They are minimum or maximum frequency or something else?

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SC
Moderator
Moderator 10 likes received 25 replies posted 10 solutions authored
Moderator

Hi,

Thanks for posting at the Infineon community.

FC, FZ, and FP are not related to the Power section. These are parameters that will be used while estimating the feedback loop compensation values.

We recommend you to refer to the below link to get a better understanding of these parameters with an example design, this reference is just for your understanding of these parameters only.

https://www.infineon.com/dgdl/an-1162.pdf?fileId=5546d462533600a40153559a8e17111a

Note: The above-mentioned formulas in the previous post will be helpful to arrive at the initial operating point for compensation design. The simulation is recommended with these values and fine-tuning is necessary before finalizing the compensation values since the converter is working on frequency modulation. CFB capacitor functions as FB signal noise filtering and also sets the extended blanking time during over load protection.

Thanks,
SPCH

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nkgavali
Level 1
First reply posted Welcome!
Level 1

Hi there,

 

I would like to post my problem related to ICE3PCS01G. But, I am not able to post on this forum. Can you please guide me why I am not able to it? it is an urgent issue.

NKgavali

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