Tool/software:
Hi!!
Used TI webench power designer for a 3.3V to 2.5V LDO using TPS74901.
Why does the circuit output show Enable pin as connected to ground through a capacitor.
Settings chosen in webench:
Vin (min & max) = 3.3V
Vout (min & max) = 2.5V
Iout Max = 2A
"Maximum efficiency" option chosen in design consideration
Thanks!!
Sathyadev,
I don't know why the connections appear as they do in the schematic. I believe the configuration that Webench is trying to display is the 1uF capacitor is tied to the bias rail/pin. En is then shorted to this connection as well. I don't know why the dot showing this is missing though. The datasheet for this device has a better schematic that shows the correct connections. EN can be tied to either IN/BIAS as long as it is above the EN threshold value of 1.1V as listed in the datasheet.
One other note, in your design VOUT is set to 2.5V. However the feedback resistors currently shown in Webench would provide a VOUT of 2.4V. Once again, I don't know why Webench displayed it like this, but if you are a seeking a 2.5V output below is one correct configuration as per the datasheet.
Best,
Jaime
