Both micro and boost converter come from the same regulated supply. It=20 is just during the turn-on transient that the supply can't act fast=20 enough and the voltage drops momentarily. Gordon On 16-10-13 07:42 PM, stephen.forrest@agilent.com wrote: > Hi Gordon - > > It sounds like your boost supply is powered from the regulated micro supp= ly. Can you power it from the unregulated supply? What is the unregulated s= upply? Is that what is actually drooping? What sort of regulator is the 5V = reg anyway? > > It's amazing how one question cascades isn't it :o) > > Stephen > > -----Original Message----- > From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf = Of Gordon Williams > Sent: Friday, 14 October 2016 9:33 AM > To: pic microcontroller discussion list > Subject: [EE] power supply transient droop > > I have a boost converter that I am switching on with a microcontroller . = The draw on the power supply goes from about 50mA to 2A and the power supp= ly drops about 1.3 volts for 10ms during turn-on. Power supply is 5V. > > During the power dip the voltage goes below the voltage allowable for the= microcontroller per the data sheet. The LEDs also flicker which I don't l= ike. > > I tried adding more capacitance at the microcontoller 330uF and this only= improved it slightly by about 100mV. > > I thought of adding a resistor or diode in the power line to the the micr= ocontroller to see if that would improve things with some bulk capacitance = at the micro. Is there a standard way to handle this to get over the short= low voltage period? > > Gordon Williams > > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/cha= nge your membership options at http://mailman.mit.edu/mailman/listinfo/picl= ist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .