SLVSCO4D July 2015 – February 2019 TPS65917-Q1
The TPS65917-Q1 device integrates an embedded power controller (EPC) that fully manages the state of the device during power transitions. According to the four defined types of requests (ON, OFF, WAKE, and SLEEP), the EPC executes one of the five predefined power sequences (OFF2ACT, ACT2OFF, SLP2OFF, ACT2SLP, and SLP2ACT) to control the state of the device resources. Any resource can be included in any power sequence. When a resource is not controlled or configured through a power sequence, the resource is left in the default state as pre-programmed by the OTP.
Each resource is only configured through register bits. Therefore, the user can statically control the resource through the control interfaces (I2C or SPI), or the EPC can automatically control the resource during power transitions which are predefined sequences of registers accesses.
The EPC is powered by an internal LDO which is automatically enabled when VSYS is available to the device. Ensuring that the VSYS pin (which is connected to VCCA, VCC_SENSE, SMPSx_In and LDOx_IN as suggested in the device block diagram) is the first supply available to the device is important to ensure proper operation of all the power resources provided by the device. Ensuring that the VSYS pin is stable prior to the VIO supply becoming available is important to ensure proper operation of the control interface and device IOs.