I want to buy some 7135 chips.
After having troubles with defective chips I need a reliable source.
Since I only need few chips I prefer a site with no (or cheap) postage fees.
What make of 7135s are Emisar using these days?
Does Emisar still use 7135s based drivers ? In the D18 ?
LCSC has the MEL7135 (”raptor claw”)
MEL7135 (and other makes of 7135 as well) caused a lot of recalls and issues from 2018-present.
I recently contacted Emisar, Convoy, and MTN, and asked which are the good 7135s to use now. None of them responded. Previously Emisar claimed to be using “the good ones,” and so I wonder which ones those are.
I don’t have any recent emisar 7135 based driver, but Fireflies use these :
!https://i.postimg.cc/2Y0zqPVn/20221023-214951.jpg !:https://i.postimg.cc/2Y0zqPVn/20221023-214951.jpg
Though maybe several manufacturer makes ones with the same logo ?
FearOfTheDark, which chips did you find to be defective?
I got bunches from Fasttech æons ago.
Given a choice, you’d want raptor-claw over crappy-sailboat, but it’s nigh impossible to specify which when ordering, as whatever comes in, comes in.
How was the defect discovered?
Does your application use pwm or some other switching scheme on the input power pin?
Maybe this “raptor-claw” and “crappy sailboat” naming convention should be revisited. I’m not sure that anyone ever actually scoped out the various 7135s and compared them, or tested the dropout voltage, etc. It could very well be that the sailboats or other makes of 7135 are better in terms of dropout voltage, but may simply require a <6,000Hz switching frequency to operate optimally.
Until someone with a scope steps up and tests several different 7135s, we won’t know.
The raptor claws were among the defective chips. These chips caused Lexel and others a lot of trouble a few years back.
Few years ago ordered from this seller. In pics original and mystical AMC7135, but seller send MEL7135 “raptor claw”.All fine.
The chip was leaking, the light was on while no voltage was applied on the input power pin and even while it was pulled down to GND
That “leak” could be that the internal FET failed short-circuit in the drain-source path => always “on”.
Measure the resistance from pin 1- pin 2 to verify; normally should be open circuit (no continuity), but failed may read a few dozen Ohms to 1 Ohm or less.
If the ic measures as shorted when new before using in a circuit, then it is definitely defective from the vendor. If it happens after usage, then the circuit board is likely poorly designed.