Because leaded paste is better.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
Not yet. I'm designing a 600 MHz oscillator, and I plan to coarse-tune it with a digital capacitor and then fine-tune it with a varicap.
These Peregrine parts look nice. There is a range of capacitance spreads in drop-in variations. One of the parts has 50 fF steps.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Not for tin-ball BGAs.
Tim
-- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
I'd try instead an OPA861; the 'emitter' and 'collector' are true and inverse current outputs, just resistor-bias and capacitor load each one. Don't worry about the gain dropping off at high frequency, to convert an input square wave to a triangle wave you WANT that to happen.
I'm going to shape a differential PECL square wave into a differential triangle with an RLC network, basically a balanced lowpass filter. That looks pretty good. The LVDS idea was cute but we didn't think it would be the way to go; the output amplitude would be poorly defined anyhow. It was just a goofy experiment.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
My guess is that they polish the bottom of the chip after molding to remove any plastic flash from the pins. This likely causes some small amount of recess of the plastic since it will polish away more easily than the metal. Then the metal pins may be coated or plated which could further accentuate the delta.
If the delta was more than 0 and less than 50 um, would you really notice?
-- Rick C
I think that is why this conversation is happening. When used in the context stated, it is not clear leaded solder is *better* than lead free.
-- Rick C
Yes-- I've measured my touch sensitivity, and I can feel about a 1 thou (0.04mm) step in an otherwise-smooth surface.
Plating is a good point. I wonder if platings are thicker than NiPdAu or Sn?
Tim
-- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
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