Other Parts Discussed in Thread: TPS65381-Q1
This thread applies to all TPS65381-Q1 and TPS65381A-Q1 devices.
When designing a system with these devices it is important to select the correct feedback resistors for the VDD1 LDO controller. Using the below guidelines as well as proper layout techniques will help to ensure proper performance from the VDD1 controller.
1. Using 0.1% resistor tolerance is important to ensure that the regulator output has a minimum shift due to resistor variation. Any resistor tolerance for these feedback resistors will cause some shift in regulator output.
2. The VDD1_SENSE pin (feedback pin for VDD1) requires a minimum amount of bias current to ensure the regulator accuracy remains within the specified values. When selecting the divider values, choose 80.6 Ω for the resistor to ground. After choosing this value the equation in section 6.2.2.2 of the TPS65381A-Q1 datasheet can be used to calculate the value of the resistor to VDD1.