Dear fellow engineers
I am experiencing a problem with a TPS63001 getting hot (like 60 deg Celcius) and consuming a lot of power (300mA @ 4,1V), yet the output voltage is regulated perfectly to 3,3v. I have found this blog post explaining exactly the same problem though with a TPS63000. Unfortunately the blog ends with a private email exchange, thus no solution published.
In my case I have designed the following schematic:
DC/DC Converter Details:
V_IN = 2,9V -> 4,2V (3,7V LiPo Cell)
V_OUT = 3,3V
C_IN = 10uF X7R
C_OUT = 2x 10uF X7R
L = 2,2uH, 1,5A, 87 mOhm
...with a battery voltage monitor to avoid deep discharge and a main switch. PCB Layout:for the DC/DC converter looks like this:
I have measured the current consumption on the battery supply line, the 3,3V output line, the control-circuit input lines and inductor for no-load and 120mA load:
| V_IN=4,1V | No load | 120mA load |
| Battery Supply | 300mA | 420mA |
| 3,3V Supply Output | - | 120mA |
| Control logic | * | * |
| Inductor output | 20mA | 130mA |
* This value is so low that I could not measure it
I can not see any other reason to this problem that the chip is broken, but I am not sure why this has happened. In the referenced blog post it is suggested that a start-up voltage peak in the inductor can damage the DC/DC Converter, but I have not yet been able to measure if my system is exposed to this kind of voltage peak.
If anyone have a suggestion to why this chip consumes so much power, and a suggestion to how I can prevent this to happen I would be very pleased.
