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LTM8064 shows small output voltage error (voltage drop) under load.  What is the normal drop?  Programmed Vout = 29.5V, but with 3.5A load it drops to ~28.5V

Question asked by wa2pyx on May 22, 2018
Latest reply on Jun 7, 2018 by wa2pyx

I have 3 of them in a load sharing circuit.  Under modest loads, everything it OK, but when I increase the load to ~3.5 - 4 A, there is a slight (~3%) drop in output voltage.  That seems a little high for a feedback regulated supply.  Sharing of load is not perfectly equal, but seems reasonably close based on the Imon outputs.  I didn't see any load regulation information in the data sheet (did I miss something?).  Output voltage "should be" 29.5V (and it's right on the money with light load) but drops to ~28.5V with the load.

 

I noticed the feedback voltage is slightly lower with the load (about 1.18-1.19 V with load, 1.22 without).  These voltages could be a little off due to the ground point I'm suing may have a slight voltage drop relative to the ground plane of the modules because of the high currents in the circuit board.

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