JAJSLW7B December 2020 – September 2023 TPS6593-Q1
PRODUCTION DATA
A multi-PMIC synchronization scheme is implemented in the TPS6593-Q1 device to synchronize the power state changes with other PMIC devices. This feature consolidates and simplifies the IO control signals required between the application processor or the microcontroller and multiple PMICs in the system. The control interface consists of an SPMI protocol that communicates the next power state information from the primary PMIC to up to 5 secondary PMICs, and receives feedback signal from the secondary PMICs to indicate any error condition or power state information. Figure 8-43 is the block diagram of the power state synchronization scheme. The primary PMIC in this block diagram is responsible for broadcasting the synchronous system power state data, and processing the error feedback signals from the secondary PMICs. The primary PMIC is the controller device on the SPMI bus, and the secondary PMICs are the target devices on the SPMI bus.
In this scheme, each primary and secondary PMIC runs on its own system clock, and maintains its own register map. Each PMIC monitors its own activities and pulls down the open-drain output of nINT or PGOOD pin when errors are detected. The microprocessor must read the status bits from each PMIC device through the I2C or SPI interface to find out the source of the error that is reported.
To synchronize the timing when entering and exiting from the LP_STANDBY state, the VOUT_LDOVINT of the TPS6593-Q1 device must be connected to the ENABLE input of the secondary PMICs, which are the target devices in the SPMI interface bus. Figure 8-44 illustrates the pin connections between the primary, the secondary, and the application processor or the System-on-Chip.
The power sequencer of the multiple PMICs are synchronized at the beginning of each power up and power down sequence; a variation in the sequence timing, however, is still possible due to the ±5% clock accuracy of the independent system clocks on the primary and secondary PMICs. The worst-case sequence timing variation from different PMIC rails is up to ±10% of the target delay time. Figure 8-45 illustrates the creation of this timing variation between PMICs.