Dear TI,
When I designed the LM22676 originally I was using the National datasheet. Now I see TI has updated the LM22676 with specific recommendations on using the enable pin and suggests not leaving it floating. I assume the TI datasheet is the correct one to following, but wanted specific guidance as to why this recommendation changed?
From TI Datasheet:
Although an internal pull-up is provided on the EN pin, it is good practice to pull the input high, when this feature
is not used, especially in noisy environments. This can most easily be done by connecting a resistor between
VIN and the EN pin. The resistor is required, since the internal zener diode, at the EN pin, will conduct for
voltages above about 6V. The current in this zener must be limited to less than 100 μA. A resistor of 470 kΩ will
limit the current to a safe value for input voltages as high 42V. Smaller values of resistor can be used at lower
input voltages.
From National Datasheet:
When enable control is not required,
the EN pin should be left floating. The precision feature enables
simple sequencing of multiple power supplies with a
resistor divider from another power supply.
