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InnoSwitch3 ok for 150W +/-DC output?

Posted by: Ricky Lam on Tue, 05/04/2021

Hi, I would like to ask if InnoSwitch3 is ok for 150W +/- DC output design? If not, any other recommendation for very no-load consumption and no heatsink?

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Submitted by PI-Radiant on Mon, 05/10/2021

Hello Ricky

 Thank you for considering our product for your application. InnoSwitch3 is most suitable upto 100W. Considering that your application requires 150W, please consider our Hiper family of ICs that support CCM boost PFC, Two-Switch Forward and resonant half bridge (LLC) converters. In case you are able to provide us with the input voltage range and the exact output voltage, we may be able to help you with choosing the exact part.




Submitted by Ricky Lam on Wed, 05/12/2021

Hi, thanks for your suggestion. Input AC voltage is full range 90Vac-265Vac

I found there is a RDR-747 65W 20V design, is it possible to use two of them, one provide +20Vdc and the other provide -20Vdc? The AC LINE filter, bridge rectifier, input 400V cap etc. is shared for the two INN3xxx 

We want design without heatsink and low no load AC power consumption, height is limited <20mm

We also need a 5Vdc @2A output, is it possible to add a DC-DC converter from the above +20Vdc output for the 5Vdc directly? The +/- 20Vdc are for power amp IC supply.

Submitted by PI-Radiant on Tue, 05/18/2021

Hello Ricky

 2 InnoSwitch ICs and 2 transformers can be used for this application, as you had described. Also, the DC-DC converter can be connected as you had described. Please note that the InnoSwitch present in the circuit which also has the DC-DC converter will be processing a higher power than the other one. You may consider using INN3679C or INN3670C ICs for this purpose.



Submitted by Ricky Lam on Tue, 05/18/2021

Hi, thanks for your reply. I have a question if the INN36xx can be replaced by INN32xx directly in the design? 

Our +/-20V is for the AMP supply, any INN3xxx pin can be used to remote shutdown the INN3xxx? We want this feature just in case there is any fault of AMP and save power when AMP is not used.  

Or do you have other suggestion to achieve this?


Submitted by PI-Radiant on Tue, 05/25/2021

Hello Ricky

 Yes, INN36xx can be replaced by INN32xx.

We can use BPP or BPS pin to achieve remote shutdown of the IC. For BPP, when the current into the pin exceeds BYPASS Pin Latching/ Auto-Restart Shutdown Threshold Current (ISD) or for BPS, if the current exceeds BPS Pin Latch/Auto-Restart Command Shutdown Threshold Current (IBPS(SD)), the IC would turn off. These values can be found in page#25 and 27 of the InnoSwitch3-CP family datasheet.