Another option might be to replace 1 diode with 2 or more smaller/cheaper in parallel to avoid the heatsink. Attached is app note from ST describing how to do it...

I using this diode
VBT3045C-E3/8W

 

I using this diode
VBT3045C-E3/8W

Are you using both diodes in the package? If so are you using any series resistance for current balancing?

 

Are you using both diodes in the package? If so are you using any series resistance for current balancing?

I am using both, I do not use anything to balance the current as each one is sufficient for my requirements.
The main reason for choosing that diode was its low Vf and the package which is very good at dissipating power and also has a matching heatsink.

 

I am using both, I do not use anything to balance the current as each one is sufficient for my requirements.
The main reason for choosing that diode was its low Vf and the package which is very good at dissipating power and also has a matching heatsink.

Agreed, its not a bad diode, but I think there are more cost effective devices that meet the requirement, e.g. V30D45CHM3_A/I which is a near identical part priced at $0.509 @ 2000off v currently $1.690 @ 1600off (Mouser)

Between that and MOSFET change that could be a cost saving of $1.84 per unit @ 2000off quantity

 

Agreed, its not a bad diode, but I think there are more cost effective devices that meet the requirement, e.g. V30D45CHM3_A/I which is a near identical part priced at $0.509 @ 2000off v currently $1.690 @ 1600off (Mouser)

Between that and MOSFET change that could be a cost saving of $1.84 per unit @ 2000off quantity

I can see that.
That is most helpful. thank you very much Irving

 

You're welcome

Incidentally, another thought would be to put the switch off MOSFET in the -ve side,, and use a N-channel MOSFET which gives many more options for low-cost devices. Of course the trade off is complications around the ground reference but these can usually be resolved.

 

You're welcome

Incidentally, another thought would be to put the switch off MOSFET in the -ve side,, and use a N-channel MOSFET which gives many more options for low-cost devices. Of course the trade off is complications around the ground reference but these can usually be resolved.

That is true ( I actualy have that solution in another part of the board), but I usually prefer to keep the return path as smooth as possible.