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INN3696C

Posted by: akanksha upadhyay on

I am designing a 20 W,24 V , for single phase input. I want my Vin to be around 440nV, but if i am selecting it, i am getting  a warning at overvoltage .

Files

Attachment 大小
InnoSwitch3-EP900V Flyback Design13.pdf 534.05 KB

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Submitted by akanksha upadhyay on 11/22/2021

And also can i design it for 3 Phase input using INN3696C.

 

Submitted by PI-Yoda on 11/22/2021

Hi, akanksha,

A value of 440V in the field specified as "Maximum AC input voltage" leads to peak mains value of 622V.

Please reconsider your input conditions.  

Submitted by akanksha upadhyay on 12/31/2021

I have designed a power supply using INN3696C, of specification 24V and 830mA ,i did not wanted the overvoltage  monitoring system so i connected the only one 3.9M resistor to the voltage pin and also connected the voltage pin to source pin of IC . But i am facing a problem , output is not as required and it keeps on fluctuating form 0.234 to 2.2 V . What can be the possible fault.

Submitted by PI-Yoda on 12/31/2021

Hi akanksha

It is look like your unit is trying to start but some protection loop kicks in and prevents is from starting.

Without detailed information about the schematics and transformer design is not possible to estimate propelry the actual operating conditions. 

 

Regards,

Submitted by akanksha upadhyay on 01/02/2022

I probably think its due to FET , what is the role of sense FET ,i observed it in the block diagram of IC .The voltage across drain to source pin of this FET (SQSA12CENW-T1_GE3) is fluctuating around 0..23 V to 6.1 V . Can i not use this Fet and go for other alternative ? I am attaching the Schematic diagram.

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PS-24V830M1P.pdf 60.16 KB
Submitted by PI-Yoda on 01/03/2022

Without a transformer design I cannot be more specific, but your synchronous FET selection - 100V rating for 24V output seems too low. 

However, I do not think that that is the reason for the restarting of your circuit. It is most likely to be a result.

 

The most likely reason for the restarting is the 5.1 Zener in the auxiliary OVP.

 

Please, use the online design tools PIexpert and/or PIXls to design your unit and check components ratings and transformer design! 

The tools will protect you from the most common errors during the design process. 

 

Regards,

 

 

 

Submitted by akanksha upadhyay on 01/03/2022

Actually i have disabled the OVP feature of it. Can i disable the SRFET application what effect will it have?

Submitted by akanksha upadhyay on 01/03/2022

Actually i have disabled that feature of OVP, i.e. i have removed the ZENER diode and left the path open and also i have removed the High value resistance of 3.9M and 442K . can i disable the SRFET feature. What pros and cons it will have?

Submitted by akanksha upadhyay on 01/03/2022

Transformer specification is as under

core - EE19

Primary turns - 82

Secondary turns- 35

Nbias turns- 19

 

Submitted by PI-Yoda on 01/04/2022

Hi akanksha

 

please create your design on PIExpert and send me a link, or the file to piexpert@power.com with the comment 'for PIYODA'

 

Best Regards

Submitted by akanksha upadhyay on 01/04/2022

In order to get input till 410V i have removed the over voltage protection feature (i.e. i have open the loop by removing 5.1V zener diode).Also i have attached two schottky diode (B2100AE ) in series in the place of SRFET and connected the SR pin of ic to its GND pin. also I  have removed  D4 ,R9 and R8. at the V pin.

Attachment 大小
InnoSwitch3-EP900VGANDA.pdf 29.65 KB
Submitted by PI-Yoda on 01/04/2022

If your unit is still not starting please do the following

1. Recover the original datasheet (DER) schematics. (no zeners in the aux loop)

2. Set the input voltage to 150Vdc

3. Set the load to 0.5A (assuming nominal output)

4. Apply the input voltage to the input terminals 

5. If the unit is still flickering some of your transformer windings leads maybe not connected correctly.

If you still struggling to get the unit running  capture the transformer windings pulses and send it to me. (please mark on which terminal the Ground of the probe is)

Ones you get the unit running at the above conditions than try to do the changes you required.

Submitted by PI-Yoda on 01/05/2022

Second picture is showing the starting signal.

Please try to zoom the amplitude so I can see the whole signal.

And do the same for the auxiliary (GND lead on pin5, sense probe on pin4)

 

Regards,

Submitted by PI-Yoda on 01/05/2022

Can you swap pins 7 and 9 on the transformer.

Pin 7 to go to the FET, and pin 9 to go to + of C12.

 

Submitted by akanksha upadhyay on 01/07/2022

yes i did that and IC got burnt after 30 sec probably.

Submitted by PI-Yoda on 01/07/2022

 

Please recover the circuit and make the output loop looks like the one on the picture below. Keep the transformer pins how they were on your original circuit.

Image removed.

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Capture_14.JPG 15.04 KB
Submitted by akanksha upadhyay on 01/09/2022

Hello,

Sorry but image is not clear.

Submitted by akanksha upadhyay on 01/30/2022

How can i reduce the ripple in the output? Output expected is 24 V but i am getting V p-p about 10V.

 

Submitted by PI-Yoda on 01/31/2022

Hi akanksha

 

The ripples in the output voltage a due to the secondary current flowing in the output capacitors and are with the switching frequency.

If you have the correct capacitors (value and ESR)  10 V ripples are extremely unlikely.

Are those ripple at low frequency? Than.. maybe your  unit is restarting because of reaching some protection level?

Please copy the actual schematics and design file (PIExpert/PIXLS). Plots with the ripples zoomed to one period will also help.

 

 

 

Regards,