Other Parts Discussed in Thread: UCC39002
Please clarify the differences btw the UCC29002D and the UCC29002D/1 bec E2E responses differ and the data sheet is a bit ambiguous. One e2e response says the difference btw the parts is only in the package. I'm leaning toward this. However, another e2e response says the difference is in the Start up and Adjust Logic block being present in the UCC29002 and not present in the UCC29002D/1. But the data sheet doesn't say that. Per the data sheet:
7.3.8 Start-Up and Adjust Logic
The start-up and adjust logic responds to unusual operating conditions during start up, fault and disable. Under
these circumstances the information obtainable by the error amplifier of the UCC39002 is not sufficient to make
the right output voltage adjustment, therefore the adjust amplifier is forced to certain known states. Similarly, the
driver amplifier of UCC39002 is disabled during these conditions.
In the UCC39002 and UCC29002, during start-up, the load share driver amplifier is disabled by the disconnect
switch and the adjust amplifier is forced to sink the maximum current through the adjust resistor. This operating
mode ensures that the module controlled by the UCC39002 will be able to quickly engage in sharing the load
current since its output will be adjusted to a sufficiently high voltage immediately at turnon. Both the load share
driver and the adjust amplifiers revert to normal operation as soon as the measured current exceeds 80% of the
average per module current level represented by the LS bus voltage. The UCC29002 and UCC29001 does not
have this logic at start up. In this way, the UCC2900x does not adjust the output of the module to its maximum
adjustment range at turn on and engages load sharing at more moderate rate.
The UCC29001 p/n referenced above appears to be a typo as well. This looks like it should be UCC29002-1. And I'm assuming the UCC29002-1 references in the data sheet align with the UCC29002/1 p/n.
Looking forward to clarity here!
Thanks & regards, John Garrett TI-AFA
