41.6.6 Sleep Mode Operation
The OPAMPs can also be used during sleep modes. The 32KHz clock source used by the voltage doubler must remain active. See Voltage Doubler for more details.
Each OPAMP x can be configured to behave differently in different sleep modes. The behavior is determined by the individual Run in Standby and On Demand bits in the OPAMP Control x registers (OPAMPCTRLx.RUNSTDBY, and OPAMPCTRLx.ONDEMAND), as well as the common Enable bit in the Control A register (CTRLA.ENABLE).
| OPAMPCTRLx.RUNSTDBY | OPAMPCTRLx.ONDEMAND | CTRLA.ENABLE | Sleep Behavior |
|---|---|---|---|
| - | - | 0 | Disabled |
| 0 | 0 | 1 | Always run in all sleep modes except STANDBY sleep mode |
| 0 | 1 | 1 | Only run in all sleep modes except STANDBY sleep mode if requested by a peripheral. |
| 1 | 0 | 1 | Always run in all sleep mode |
| 1 | 1 | 1 | Only run in all sleep modes if requested by a peripheral. |
When OPAMPCTRLx.ONDEMAND=1, the analog block is powered off for the lowest power consumption if it is not requested.
When requested, a start-up time delay is necessary when the system returns from sleep. The start-up time is depending on the Bias Selection bits in the OPAMP Control x register (OPAMPCTRLx.BIAS) and the corresponding speed/current consumption requirements.