TPS2116: TPS2116 – Clarification on Priority Behavior When Input Voltages Are Equal / Close & Deterministic Priority Configuration

Part Number: TPS2116
Other Parts Discussed in Thread: TPS2121

Hello TI Team,

I am using the TPS2116 as a dual-input power multiplexer between USB 5 V (VIN1) and a regulated 5 V battery rail (VIN2) for a flight controller design.

I would like clarification on the following points:

1. How does TPS2116 determine priority when both inputs are equal or very close in voltage?

For example, if VIN1 = 5.02 V and VIN2 = 5.01 V, or both are exactly 5.0 V, what are the internal decision criteria used by the part?

Does the part rely purely on voltage comparison, or is there an internal hysteresis or timing mechanism that decides which input becomes active?

2. What is the recommended method to enforce deterministic priority (e.g., always VIN1 preferred over VIN2) even when the voltages are nearly identical?

Should we use D0/D1 configuration for forced priority, or is there a specific recommended configuration for stable switching in equal-voltage conditions?

3. Any additional layout or design guidance

If there are TI app notes or known best practices regarding:

• priority behavior tuning

• transitions when both rails are nearly identical

• avoiding unnecessary toggling between inputs

…please share them.

Thank you for your guidance.
— Sushant Chaturvedi