Temp and Vdd could be responsible for most of the possible variation in GPIO current.
But the datasheet doesn't tell us.
Mouser sells the Si4432 by the 2500 piece reel at $4.19 each.
Makes me wonder if the $2 Si4432 modules on ebay are using a $0.25 clone,
or perhaps factory seconds.
GPIO current is not something a clone manufacturer would monitor closely.
>? Output voltage measured with calibrated scope terminated also 50ohm (so total of 25 ohm to ground) is 47mVpp.
>? The shape is a good square wave. So this should be the reference level of -22dBm in the fundamental
Very cool.
I've got a bunch of the ElectroDragons winging there way to me now, as I type.
Looking forward to playing with them.
Not only for use as an SA, but also for their intended purpose
of?short range digital communications
I wonder how much temperature affects the RSSI values we read from the Si4432.
Perhaps once we run out of other things to do, we could correct the RSSI values
using the internal temperature sensor
Though quite possible that SiLabs already does this internally.
Jerry, KE7ER
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On Sat, Jan 4, 2020 at 08:54 AM, Jerry Gaffke wrote:
Page 12 table 7 of the Si4432 datasheet shows that the GPIO outputs
can be programmed to four different levels.
That table also shows that with the drive level set to its maximum of Iomaxhh,
it might be able to deliver only 1.8 ma, or as much as much as 5.4ma.
So GPIO's on some Si4432 chips might have 3x more available output current than others?
due to process variations,?die location on the wafer, or phase of the moon.
That's 3*3= 9 times more power, almost 10dB.
We will probably never see it that bad, but even 2 or 3 dB variation is not welcome here.
