Is it detrimental to an SMPS to turn it on and off frequently


I've got a 5V SMPS powering two separate servos:

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The smps is a tps562200

The application is an autonomous sail boat (3 feet long). One's a winch, the other a rudder. I have code that scans various sensors and when appropriate makes adjustments, anywhere between every 2 seconds and every 30 seconds (depending on how stable things are). The two servos never need to be active at the same time. To not waste power on the switcher's quiescent current, I pull its EN line low whenever not in use.

I'm looking at two possible options:

  • disable the switcher in between each servo access
  • be a little smarter about it, and keep it enabled during the autopilot cycle

From an power savings standpoint, turning off the switcher more than makes up for the energy lost in recharging the caps on the servos, but does this much cycling do any damage to the switcher / associated circuitry?

Best Answer

No, there is mo problem in using the enable lead to turn on and off the SMPS as often as you want to. In fact, internally, that is how a buck converter works:

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The switch between the supply and the rest of the TPS562200 buck converter is being turned on and off 650,000 times a second.

I have connected up the enable lead of a SMPS boost converter to a PWM output of a LCD controller, thus turning it on and off several times a second, without any issues.