LMR14030 Abs Max input voltage: 44V
TPSMA6L36A Max breakdown voltage: 44.2V
TPSMA6L36A Max clamping voltage: 58.1V
Do you see the problem? The TPSMA6L36A doesn't clamp low enough to protect the LMR14030.
You'd need to either go down to a TPSMA6L26A to get the clamping voltage under 44V:- Vr: 26.0V, Vbr_min: 28.90V, Vbr_max: 31.90V Vc: 42.1V @14.3A,
or add a MOSFET over-voltage disconnect circuit after the TVS and before the bulk capacitor.
The resistor needs to be in series with the feed, before the TVS as its purpose is to limit the energy into the TVS. Without a resistor, if the TVS clamping voltage is below that of the central protection it has to be able to handle anything up to the full worst case load dump (pulse 5B) with the only limits on the pulse energy being the max alternator output current and the wiring resistance.
If you are building this as a permanently installed one-off, you can check the specs for the central clamping used in the specific vehicle and design the protection based on that clamping voltage. However if its a portable device you need worst case any vehicle protection.
There's also the matter of the value of the device and anything attached to it. So far we have an android phone, a uC board and unspecified peripheral boards. Put a dollar value on that lot and estimate what its worth spending on protection circuits to insure against damage due to the rare fault of your battery ground strap or terminals working loose while driving along.
(If either are loose initially, odds are you'll have starting problems., so you wont get as far as causing a load dump)One final point on vehicle maintenance, which has had the finger of suspicion pointed at it in this thread. There has been the suggestion that if the battery is maintained, and all the connections then there should not be a problem. Speaking from, my limited, experience the hardest thing to track and most common problem is bad earth connections to the vehicle chassis. I'm not sure that can be ignored and called something that should not happen. It just does. Be great if there was a sensor of some sort that warned you that spikes are starting to occur and you should check your connections and battery.
The nightmare one is the ground strap from the engine block or bellhousing to the chassis. The engine itself will be on rubber mounts, so that strap flexes every time you accelerate, brake, corner or shift gear. Eventually it will fatigue, and if it breaks while running with a high load on the electrical system *BAD* things happen. Its often in a really awkward place to get to to inspect, and with the usual dirt buildup you are unlikely to spot its got broken strands before it totally fails even if you are absolutely anal about maintenance. If you are lucky, the strands will break gradually a few at a time and when it gets too weak it will pop like a fuse one morning when you try to crank the starter.