zm33064/inductor necessity

hello,

i’ve had a great time with the olimex dev boards. they are outstanding. i’m designing a small pcb for a project and i’d like to know more about the necessity of the zm33064 voltage-reset monitor chip, from a design/reliability perspective. the project will be usb bus powered.

also i noticed on the schematic and on the board that there is room for an inductor on the usb line, but it’s not present (a jumper is there instead.) should i add one to my design (it seems to work fine as is?)

cheers, and thanks!

brian

please always include external reset to your AVR designs, without external reser AVRs corrupt their flash during power supply glitches.

The inductor on USB line is necessary only if you want to use the ADC as the noise from the USB line will drive your ADC crazy when measure values around 0V, otherwise it’s not necessary.

Tsvetan

i appreciate it!

Hi Olimex,

the ZM33064 has a threshold voltage of 4.6 volts. Can you recommend an equivalent device for lower-power designs? Specifically, I’m looking at the 3V-3.7V range…

thanks!

OLIMEX:
please always include external reset to your AVR designs, without external reser AVRs corrupt their flash during power supply glitches.

I thought most of the AVRs have brownout detection? If rownout detection is enabled, do I still need an external reset?