Question
Part Number: AD8237
Can the BW pin of AD8237 be controlled with a GPIO on a MCU?
Answer
We see no problem with this. Advisable to use a pull-up resistor of about
4.7k ohms to the BW pin and interface to a microprocessor to control this
pin. e.g. control and output high or low to simulate this Vs or -Vs (gnd)
The BW pin is one input of a comparator. It is high-Z, there are no current
driving requirements, and there are no minimum rise/fall time requirements. The
other input of the comparator is at a resistor divider from +Vs to –Vs, which
creates a half-supply voltage for comparison.
Threshold voltages: High is (+VS + (–VS))/2 + 60mV min, Low is (+VS + (–VS))/2
– 60mV max (this takes into account worst-case process variation and also 30mV
of hysteresis)
Propagation delay: typically 10µs comparator propagation delay + the settling
time of AD8237 in the final configuration