Post by thread:[PIC] Reset with slowly-rising Vdd

Hi all, I have an application which uses an 18F45K20 and where the Vdd rises at about 100 V/sec. The datasheet says that a special circuit should be used on MCLR (an RC network) when Vdd rises slower than 50V/sec. I am a little concerned about how close I am to that spec. I am also using the brown-out reset module. I'm wondering if the minimum Vdd rise time spec still applies when BOR is enabled. The datasheet doesn't seem to say explicitly one way or another. Thanks, Sean

On Tue, May 12, 2009 at 2:05 AM, Sean Breheny <spam_OUTshb7TakeThisOuTcornell.edu> wrote: > Hi all, > > I have an application which uses an 18F45K20 and where the Vdd rises > at about 100 V/sec. The datasheet says that a special circuit should > be used on MCLR (an RC network) when Vdd rises slower than 50V/sec. I > am a little concerned about how close I am to that spec. I am also > using the brown-out reset module. I'm wondering if the minimum Vdd > rise time spec still applies when BOR is enabled. The datasheet > doesn't seem to say explicitly one way or another. If you are worried, it is better to use an external voltage monitoring circuit. Microchip has quite some ICs for the application. -- Xiaofan http://mcuee.blogspot.com