[Ronja] Twister2 power problem

[Karel Kulhavy]

---- Bruce M Simpson <bms at incunabulum.net> schrieb:
> Bruce M Simpson wrote:
> > I'm only seeing 0.82V on the output from the 2671M-5.0 (double checked 
> > at U66 and other test points).
> > I am using the National Semiconductor version of this part.
> >
> > The chip and the schottkys, caps etc appear to be in the correct place.
> > What could be the problem? Interestingly I see around 6.3V on pin 5.
> >   
> 
> I just looked at the LM2671 data sheet and I see that it seems to be 
> very, very picky about the inductors which it needs.
> 
> I haven't, unfortunately, been able to obtain the exact parts in the 
> Twister2 BoM here in the UK. I have mostly been sourcing parts through 
> Farnell, however it looks like RS have a number of parts which they don't.

So what did you put there instead? How much inductance?

CL<
> 
> When I drive the 5V line directly from an external regulated supply, the 
> Twister2 idle pulse and transmit functions normally (confirmed with the 
> scope). So it looks like the silicon is OK. I haven't verified the 
> receive path yet.
> 
> cheers
> BMS
> 
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