LT3045 and LT3094 almost always DOA

I have a design that uses two LT3045's and an LT3094, and most of these LDOs never work.

An LT3045 configured for 4.99V out (49.9k set resistor) typically sees 1.96V on the set pin.  I have verified that the current source simply isn't working.  The LDO is also supplied with 8V.

The output doesn't even match that, putting out about 0.36V instead.  I removed the chip and tried a brand new one, and I observe the same behavior and voltages.  I have verified that all the passives surrounding the chip are correct and working.

The LT3094 generally goes with a different approach, outputting nothing on either the set pin or the output.  This one is the same as the first, but everything is negative.

Out of 5 LT3094s, 5 did not work.  Two were soldered properly in a reflow oven, so they weren't cooked.

Out of 6 LT3045s, 4 did not work.  Four were soldered in a reflow oven.  One set for 4.99V does work correctly.

Here's the LTSpice of the actual circuit, which works just fine.

Parents Reply Children
No Data