In the LTC2977, are the enable pins VOUT_EN [0:7] mapped to VSENSE[0:7] and VDAC[0:7].
If I'm using VSENSEP0,VSENSEM0 and VDACP0,VDACM0 for controlling the 5V POL, can I use VOUT_EN1 for enabling the 5V POL?
Generally no, we do not recommend you mix channel resources. This doesn't mean that it can't be done, just that it gets tricky. It depends a number of things.
If CH0 get enabled with the VOUT_EN1, then what are Vsense1 pins to? And what is VOUT_EN0 connected to? You must set all output voltage fault responses to 'ignore', otherwise the OV/UV/TON_MAX limits will be exceeded and a fault detected. ALERT will pull low and status will be updated even if the channel is not shut down. Also how is Vdac0 first connected to 5V POL? That is, you can't use soft-connect mode since you're not using the enable. I might be missing something else, but as you can see, there are a number of items that you must take care of. Maybe we can arrange to have a look at your schematics to get better context.
You might find the entry in the FAQ that covers channels that are used only for monitoring useful. See sections 1.1.6 and 1.1.3.http://ltpowerplay.com/help/PSM-FAQ.pdf
I did not clearly explain the question before. I was reusing the power management portion from another design which is not tested yet. In that design, I observe that the enable pins are not in accordance with the Sense and DAC pins. For example: Sense0 and DAC0 pins are connected to the 5V POL, Sense1 and DAC1 are connected to the 3.3V POL, Sense2 and DAC2 are connected to the 1.8V POL but Vout_en0 is connected to 3.3V POL, Vout_en1 is connected to 1.8V POL, Vout_en2 is connected to 5V POL. Is this a correct configuration? Is there any register that allows us to configure Vout_en1 pin to work with Channel0 etc?
Unfortunately, I could not share the schematic.
The numbered Vout_en/Vsense/DAC pins should be tied to the same channel. In your case, VOUT_EN0 should be tied to the RUN/enable of the 5V POL, VOUT_EN1 should be tied to the 3V3 supply, and so on. If CH0 detects a fault based on the Vsense pin, it will shut down the 3.3V POL which is unexpected. And if Vsense2 (1.8V POL) detects a problem, the chip will shut down the 5V POL, again unexpected.
There are no register settings to re-map the enables, unfortunately. Can you re-route the enables?
Thank you, Mike. I've rerouted the signals.