Hey guys, I created this circuit that takes a single coin cell battery (panasonic lithium cr2477) and run it into a AAT1217ICA-3.3 which boosts the battery voltage to 3.3V, and maintains the 3.3V as the battery drains. The AAT1217ICA-3.3 also has a SHDN pin (high keeps the regulator running, low shuts down the regulator). I have a timer IC (TPL5111) connected up to the AAT1217ICA-3.3 SHDN pin.
This works by on initial startup, and every 3 minutes, the timer activates the AAT1217ICA-3.3 SHDN pin. The microcontroller does some work, then signals its done to the timer. The timer will then deactivate the AAT1217ICA-3.3 and wait 3 more minutes before re-activating it, and this is an endless loop.
If I remove the battery, and connect up a 3.3V power source, everything works just fine; 3.3v rail is regulated, microcontroller does work and signals to timer its done, and timer shuts down regulator. However... If I try to take a current draw measurement with a volt meter (by intercepting the power wire), the regulator won't start up and it continuously resets. If I use the coin cell battery like normal, I get the same problem... the regulator won't start up and it continuously resets.
Here is my circuit schematic:
Here is monitoring the lithium coin cell voltage right at the battery (continuously resetting):
Here is monitoring the timers DRVn pin that activates the AAT1217ICA-3.3 SHDN pin (continuously resetting):
Here is monitoring the 3.3V rail (continuously resetting):
If anyone could offer any help or advice on how to troubleshoot this thing, it would be greatly appreciated, thanks!
This works by on initial startup, and every 3 minutes, the timer activates the AAT1217ICA-3.3 SHDN pin. The microcontroller does some work, then signals its done to the timer. The timer will then deactivate the AAT1217ICA-3.3 and wait 3 more minutes before re-activating it, and this is an endless loop.
If I remove the battery, and connect up a 3.3V power source, everything works just fine; 3.3v rail is regulated, microcontroller does work and signals to timer its done, and timer shuts down regulator. However... If I try to take a current draw measurement with a volt meter (by intercepting the power wire), the regulator won't start up and it continuously resets. If I use the coin cell battery like normal, I get the same problem... the regulator won't start up and it continuously resets.
Here is my circuit schematic:
Here is monitoring the lithium coin cell voltage right at the battery (continuously resetting):
Here is monitoring the timers DRVn pin that activates the AAT1217ICA-3.3 SHDN pin (continuously resetting):
Here is monitoring the 3.3V rail (continuously resetting):
If anyone could offer any help or advice on how to troubleshoot this thing, it would be greatly appreciated, thanks!