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+--- Thread: safe fanout for Digital outputs? (/showthread.php?tid=4811)
safe fanout for Digital outputs? - ealbers - 07-25-2017
How many outputs can a GPIO drive?
I have several ADC's I want to send a clock signal too all at the same time, is there a general rule of tumb of how many devices a pine output can drive at once?
Thanks!
I should mention I'm clocking a dozen or so ADC0832's, they are all reading hall effect sensors
RE: safe fanout for Digital outputs? - MarkHaysHarris777 - 07-25-2017
(07-25-2017, 12:45 PM)ealbers Wrote: How many outputs can a GPIO drive?
I have several ADC's I want to send a clock signal too all at the same time, is there a general rule of tumb of how many devices a pine output can drive at once?
Thanks!
I should mention I'm clocking a dozen or so ADC0832's, they are all reading hall effect sensors
Always refer to the datasheet.
... having said that, typical fanout is about 10. Depending on TTL or CMOS technology. TTL is a current sinking logic so fanout is more constricted. Each device by logic type is somewhat different.
If you are concerned about it, then use an inverter | driver or just an hex driver buffer between your devices and the clock output signal. A half dozen or so should not be a problem regardless.
Read the datasheet.