Chapter 3: AT Commands Reference
June 30, 2008 AT Commands Reference Manual 3-233
OK
AT+MVREF=2 //The user set STANDBY and the Vref regulator will enter into ON
mode.
OK
ATS24=2 //Vref regulator will enter into Low Power mode.
OK
ATS24=0 //Vref regulator back into ON mode.
OK