ZHCSKK3B December 2019 – February 2022 TPS6594-Q1
PRODUCTION DATA
The LDOVRTC voltage regulator supplies always-on functions, such as wake-up functions. This power resource is active as soon as a valid VCCA is present. The LDOVRTC voltage regulator is dedicated for internal use only, and cannot be used to support external loads. An output filtering capacitor must be connected at the VOUT_LDOVRTC pin. Do not connect any other components or external loads to this VOUT_LDOVRTC pin.
This voltage regulator is enabled in normal mode or backup mode. The LDOVRTC voltage regulator functions in normal mode when supplied from the main system power rail and is able to supply the input buffers of GPIO3 and GPIO4, the digital components, the crystal, and the RTC calendar module of the TPS6594-Q1 device. The LDOVRTC voltage regulator remains on in BACKUP state when VCCA is below the VCCA_UVLO level, and the backup power source is above the LDOVRTC_UVLO level.
Only the 32 kHz crystal and the RTC counter are activated in the BACKUP state. The RTC calendar function remains active in the LP_STANDBY state, but the interrupt functions are reduced to maintaining the wake up functions only. The RTC calendar and interrupt functions are fully activated in the mission states.
The customer has the option to enable the shelf mode by setting the LDORTC_DIS bit to 1 while the device is in the MISSION state and the I2C bus is in operation and ramp down VCCA to 0 V immediately after the I2C write has completed. This shelf mode forces the device to skip the BACKUP state and enters the NO SUPPLY state under VCCA_UVLO condition. This mode is useful to prevent the continual draining of the backup power source when the 32 KHz crystal and RTC counter functions are no longer needed.