Buzby
Senior Member
Hi All,
The 20mA output capability of the PICAXE is not enough for my next project, I need about 200mA source and sink for each pin.
Designing a buffer with two MOSFETS, ( one P one N ), for each pin is quite easy, - but I need tristate as well.
The 'normal' way would be to use another pin and a bit of gating to 'turn off' both FETS.
But I want the FETs to go tristate when the PICAXE pin goes tristate, without using an extra signal.
I'm fairly certain it could be done with some clever biasing or a couple of diodes, but I don't want to spend time re-designing if it's already been done.
There may even be a buffer IC somewhere, but I don't know where to start looking.
Any ideas ?
Thanks,
Buzby
The 20mA output capability of the PICAXE is not enough for my next project, I need about 200mA source and sink for each pin.
Designing a buffer with two MOSFETS, ( one P one N ), for each pin is quite easy, - but I need tristate as well.
The 'normal' way would be to use another pin and a bit of gating to 'turn off' both FETS.
But I want the FETs to go tristate when the PICAXE pin goes tristate, without using an extra signal.
I'm fairly certain it could be done with some clever biasing or a couple of diodes, but I don't want to spend time re-designing if it's already been done.
There may even be a buffer IC somewhere, but I don't know where to start looking.
Any ideas ?
Thanks,
Buzby