Other Parts Discussed in Thread: TPS2113, TPS22930A, LM66100
I have an application where I’m using TI’s TPS2113A power mux to select between a battery source (3XAAA) or a USB wall adapter, maximum current will be 1A. We don’t care about nor need the “seamless supply transition” feature, meaning that there is no requirement for the system to maintain power while transitioning from one power source to another. With this in mind, I have the following questions:
- The datasheet shows 0.1uF caps at IN1 & IN2 pins, which I’ve added for now in my attached schematic (C7 and C8). For my case, the output of the power mux goes to 2 back-to-back LDOs (3.3V LDO and then 2.8V LDO). Each of those LDOs already has the TI recommended caps at the inputs and outputs. In that case, do I still require the 0.1uF caps at the power mux IN1 and IN2? What’s the impact of removing those caps? I do want a clean power supply but I don’t care about the time it takes to switch from one power supply to another.
- If I don’t require the use of the “STAT” pin, what should I do with it? Should I keep it floating or is it safer/recommended to tie it off or ground, either directly or through a resistor?
- Just to confirm, this power mux does provide reverse voltage protection? Ie. If the user inserts batteries in reverse polarity, will this power mux protect against damage?
- I’m confused about the power rating of the two different packages (SON-8 vs TSSOP-8) on page 2 of the datasheet. Isn’t the power consumed by TPS2113A just a function of the current and the Ron? If my current is set to 1A and Ron is a maximum of 110mOhm, then power will be 0.110 Watts (p=i^2R). Since for most temperatures, SON-8 package power rating is much less than 0.110 Watts (only 2.5mWatt at 25 degrees), does that mean, I must use the TSSOP-8 package, or am I interpreting that table incorrectly?