MinE-CAP ultra wide input range (DER-712)

Posted by: contact@ibpetter.de on 01/17/2025

I am urgently looking for advice on an ultra-wide input design. I am using a circuit very similar to the reference design DER-712.
This raises 3 comprehension questions for me:

To what extent does R42 disable the UV/OV feature of the Innoswitch? This is neither mentioned in the datasheets, nor annotation notes...
Does the MinE-CAP have overvoltage protection? At what current at V top?
Can I lower the threshold for the brown-in with an additional circuit consisting of a resistor and a diode between BPP and V top? As is suggested for the Innoswitch3...

Background: At the moment I am using the additional circuit from question 3, which effectively lowers the brown-in. L and V are directly connected between MinE-CAP and Innoswitch3. Unfortunately, it also lowers the upper voltage threshold by exactly the injected current. So I have only shifted the input voltage window, but not widened it. Do you have any useful ideas?
The rest of the circuit works great over the whole range I need for the industrial power supply.

Best Regards from Germany
Andreas Petter

Comments

Hi Andreas Petter,

Thanks for question and interest to use our product.

May we know the design parameter of the Power Supply that you are designing. Vin, Vout Output current, Power Integration IC that you are using.

For proper discussion can you attach the circuit being describe in Question 3.

For question number 2, MinE-Cap does not have overvoltage protection. the MineCap passes the input voltage information via its L pin to INNO3 Vpin .

Thanks

Regards

PI-Chloe

Hi Cloe,

here is the interesting part of my schematic.
R2 alone (no R4 & D1) gives a working range of roughly 100 to 450 VDC at PRIM-DC. Right?
Introducing D1 and R4 (as suggested in annotation notes of the InnoSwitch) injects an additional current. This lowers the brown-in of both IC's down to around 45 VDC, which is the intended startup voltage.
My Problem is, that the additional injected current also lowers the upper boundary (OV-Limit) from 450 down to 390 VDC. This is not intended. What I need is a working range from 45 to 450 VDC. How can I achieve this?

Additional Informations:
- Output is 24V and 1.5A (36W). All other circuit works well and in safe ranges.
- Maybe the voltage level at VTOP of U1 is always much lower than BPP and different from V pin of U2.
- DER-712 Reference-Design have an additional resistor of 20k between L of U1 and V of U2. Why? What is the effect of it?

Thank you for your help in advance.
Best Regards, Andreas

Attachment	Size
interesting part of schematic (9.52 KB)	9.52 KB

I have found a solution for myself. To anyone, who might be interested...

Lower the Brown-In for both MinE-CAP and Innoswitch3 can be achieved by injecting a current from BPP into Vtop of MinCap-E using a diode and a resistor in series.
Inserting a resistor of 20kΩ between both IC's (L to V pin) indeed disables the OVP feature of the Innoswitch3. I protect my device with a varistor at input line.
With these 3 cheap solutions, you can achieve an ultra wide input range of 1:10 or more. :)

Hi Andreas

Thanks for the information Andreas.

I'm also searching internally on how the design was created specifically the basis of the 20Kohms. Based on the document that I have read the 20kohms function to disable the Line OVP.

Really appreciate your effort on performing the evaluation.

Many Thanks

PI-Chloe