# Sleep Current vs. Wake-Up Time

The Low-Power Sleep mode can be selected by setting the VREGPM bits as following:
• VREGPM = ‘b00; the voltage regulator is in High Power mode. In this mode, the voltage regulator and reference circuitry remain in the normal configuration while in Sleep. Hence, there is no delay needed for these circuits to stabilize after wake-up (fastest wake-up from Sleep).
• VREGPM = ‘b01; the voltage regulator is in Low Power mode. In this mode, when waking up from Sleep, an extra delay time is required for the voltage regulator and reference circuitry to return to the normal configuration and stabilize (faster wake-up from Sleep).
• VREGPM = ‘b10; the voltage regulator is in Ultra-Low Power mode. In this mode, the voltage regulator and reference circuitry are in the lowest current consumption mode and all the auxiliary circuits remain shut down. Wake-up from Sleep in this mode needs the longest delay time for the voltage regulator and reference circuitry to stabilize (lowest current consumption).
• VREGPM = ‘b11; this mode is the similar to the Ultra-Low Power mode (VREGPM = ‘b10), and is recommended ONLY for extended temperature ranges at or above 70℃.