Greetings we are using the TPS2411 for a redundant power supply design and during the test process we encounter some unusual behavior from the oring controllers. A shcematic of the circuit is below:
Rset = 100k
which allows Vca of 1.56mv before shut down. with an Ron of 7 mOhms it allows a revers current of 222 mA of revers current. The problem is that we have an input voltage of 3.4V to one of the oring controllers and 3.2V to a second one connected in parallel. the differences in voltages is to have an additional margin and to establish a preferred power supply. at no load or relatively high load (around 3.7K) we see the 3.4 output. but as we try to extract more current we get and unexpected voltage drop:
@120mA: Vout = 3.34V
@435mA: Vout = 3.15V
@1A : Vout = 3.0V
to try to solve this problem we have tried the following:
1) testing only one Oring controller at once, almost same result
2) increasing FLTR up to 100uF, almost same result
3) changing from resistor loads, constant current loads and even the system we expect to power as a load, no changes
4) changing the ICs and Fets
5) removing the LEDs from the system
the jumper are only to enable the LEDs, debugging purposes or reading the Stat pin. We have tried every thing that we could think was the problem but had no results, any help or advice will be Greatly Appreciated.
Thanks
