ZHCSI59I July 2009 – May 2018 TPS65070 , TPS65072 , TPS65073 , TPS650731 , TPS650732
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
At first power-up (start-up from OFF state), the voltage for VDD_PDN is ramped at the same time than VDD_PRE. This is defined by Bit MASK_EN_DCDC3 in register CON_CTRL2 which is “1” per default. For enabling SLEEP mode, Prima needs to clear this Bit, so the EN_DCDC3 pin takes control over the DCDC3 converter. Prima SLEEP mode is initialized by Prima pulling its X_PWR_EN pin LOW which is driving the EN_DCDC3 pin of TPS6507x. This will turn off the power for VDDPLL (LDO1) and also for VDD_PDN (DCDC3). All other voltage rails will stay on. Based on a “keypress” with PB_OUT going LOW, Prima will wake up and assert EN_DCDC3=HIGH. This will turn DCDC3 and LDO1 back on and Sirf PRIMA will enter normal operating mode.