Hello, TimeNutters- Silicon Labs [1]http://www.silabs.com/products/clocksoscillators/pages/default.aspx offers a large assortment of various types of oscillator chips: XO, VCXO, programmable XO, clock generators, clock distribution chips, Jitter Attenuators, Clock cleaners, etc, etc.... I have a need for a 110 MHz VCXO in a 1.8GHz to 7.5GHz tracking generator I am building for my Tek 494 spectrum analyzer. I bought a pair of Silicon Labs 110 MHz VCXO chips for less than $25 for the pair from Cramer Distributors. The Si595 VCXO chips are in an "industry standard" 5mm X 7mm surface-mount package. Yikes! I knew I was going to have trouble (for lack of thru-hole leads) breadboarding this chip. However, I managed (using a magnifier-loupe and a v-e-r-r-r-y tiny soldering iron tip) to get some "legs" soldered onto the surface-mount pads. Great... I inserted the critter into the socket-strips of my breadboard, hooked up the required 3.3vdc Vdd and ground and checked to see what it's output looks like. No joy. Drat. It has a set of complementary output pins. One sits at around 50% of Vdd and the other is low. When I pull the Output Enable pin high, the 50% output pin goes low. The other (complementary) pin just stays low. If I pull the Output Enable pin low, neither output pin changes. Drat. I must have destroyed the little critter during the leg soldering process. These chips are supposed to be pretty static from normal handling and-- here in humid Flori-DUH, handling problems from static build-up is almost a non-existent problem. Even so, I do all my breadboarding on a 3-foot X 2-foot static-drain pad. Sooooo.... I used the utmost care in soldering legs to the second chip. The surface-mount pads are gold-plated and it is super easy to just momentarily tap them with the soldering iron tip and leave a very teensy blob of solder on each one. Using pre-tinned gold-plated legs stripped from some surplus 1/8 Watt resistors, I fastened the legs on the chip with only the briefest time of soldering-iron tip contact; less than one second, I am guessing. Same result with the second chip; the outputs appear to be dead. I guess this sad saga boils down to my question for the Time-Nutters List: How do you deal with breadboarding when it comes to parts that are ONLY available in surface-mount configuration (and are just at the size limit for hand soldering? Thanks for any input on this! Mike Baker Micanopy, FL ------------------------
References 1. http://www.silabs.com/products/clocksoscillators/pages/default.aspx _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.