DPA422PN UV AND OV CALCULATION PROBLEM

Posted by: 168 on 02/13/2012

dear pi engineer:

the picture attached is from the datasheet of the DPA422PN.

can u explain these two equations for me? what does IUV stands for? what is the value of VL?

Thank u in advance...

Comments

Hi,
I_UV stands for line under-voltage threshold current. This is the minimum Line sense current that needs to flow into L pin to start switching. It is a technique to sense the line voltage. Typically I_UV is 50uA and I_OV is 135uA as shown in Typical Electrical specification table. V_L is line pin voltage for respective Line under (2.35V) and over (2.5V)threshold currents. Please refer to Specification table in the data-sheet.

So to explain the 2 equations:
VUV = IUV x RLS + VL (IL = IUV) (determines Min input voltage to turn ON the switcher)
VOV = IOV x RLS + VL (IL = IOV) (determines Max input voltage to turn OFF the switcher)

So you can use this equation to set your Minimum and Max Input (Line) voltage.

rgds..

thanks for ur reply.according to ur opinion, i should use IUV=50uA and VL=2.35v to calculate the VUV. and i should use IUV=135uA and VL=2.5v to calculate the VOV. do i understand u correctly?

Yes, your are right.

rgds