gerg:
I purchased an arduino which is based on 5v but I will need to drive some 3v RF modules. I was planning on using a voltage divider, built with some simple resisters. In reading about them, I found several posts which indicated voltage dividers imposed a performance hit. As such, others recommend the use of a logic level converter rather than a voltage divider. I was under the impression no such performance hit would occur since it was built strictly with resisters, having no capacitors.
1Can someone please clarify if a voltage divider does in fact impose certain performance negatives and if so, why?No performance hit if the reduced voltage is for logic signal inputs for external components (like your RF module), if for providing significant current for some purpose then it's not a solution.
2Can someone please clarify when one should use a voltage divider and when one should use a logic level converter?Again it's about what current demand is as well as voltage level. If significant current is required then don't use resistors.
For completeness, if I do need a logic level converter, I'm looking at these. And the RF modules I'm looking at these.
Voltage dividers should work fine. Of course you only require voltage dividers for the arduino digital output pins driving the RF module. The 3.3vdc logic signal outputs from the RF module wired to the arduino input pins must be wired directly as a 3.3vdc logic high is high enough to be read as a high logic level in a 5vdc arduino board.
Thanks.