The Antona chip test adapters provide the designer with a method to access and monitor (or inject signals) on all of the component pins for socketed PLCC (plastic leaded chip carrier) or PGA (pin grid array) type packages.
PLCC type components
The user need only remove the component from the designer's circuit board socket with a PLCC extraction tool (make sure power to the target circuit card is removed). Follow the component removal instructions for the particular socket on the user's circuit board to insure no damage occurs to the PLCC chip itself. Generally there are slots on opposing corners of the socket into which the end of the component removal tool is pushed under the chip and then gently pried up. Plug the Antona adapter into the component socket and then put the component into the top layer socket before reapplying power to the card. When placing the component into the top layer card, be sure to align the chamfered corner of the PLCC type chips with the chamfered corner of the socket (upper-left, with chamfered corner of adapter circuit board). Probes may now be attached to any component lead by using the numbered goldplated test points provided on the top layer adapter card. Optional top layer cards are available from Antona for different pin numbering, and/or component type. An adhesive backed numbering sheet is also included with each adapter should the user desire to change the top layer numbering to accommodate other pin numbering configurations.
Changing Base Target Chip Type - PLCC to PGA
The adapter is built of stacking plug layers which may be changed to accommodate various types of components. The 20 and 28 pin test adapters do not have a removable base. The 20 and 28-pin PGA is rarely encounter, however we can provide a mating PGA base for the 20 or 28 pin version if needed The PLCC base layer, standard on all other versions of the test adapter, may be removed and a PGA socket installed, for use on that type of socketed component. A PGA socket is included with the purchase of the test adapter to plug into the base unit's pins (providing a level of protection for the 0.018" diameter pins). Note that pin numbering on the PGA target component may be different than the top level silk-screened numbers. The enclosed numbering sheet may be used to apply numbers either temporarily or permanently to the top level. Again, optional layer cards are available to accommodate the different pin numbering (life would be much easier is ALL components were numbered uniformly). To convert back to PLCC type target chip socket use, carefully remove the added PGA socket by prying, with a small blade screwdriver, between each corner of the socket and the base unit's soldered PGA socket. Work slow and just pry a little bit on each side until the 2 pieces come apart. Do not try to pull the 2 pieces apart as damage to the base unit socket pins may occur. Some users may prefer to leave the 2nd PGA socket installed. Align the chamfered corner of the PLCC plug with the chamfered corner of the circuit board and plug the PLCC adapter into the mating matrix of pins on the base adapter card.
Changing Top Layer Chip Type - PLCC, PGA or LCC
The top layer of the test adapter may be changed to accommodate PLCC, PGA or LCC (leadless chip carrier) type components. This means you can "mix and match" component foot prints if required. Contact Antona if additional socket options are desired. When separating or mating the layers, be careful not to bend the pins and double check for proper pin alignment. Avoid using a sharp tool to pry the layers apart as this may cause damage to the traces on the base level. Note that there is a 1/16" space between layers when they are properly pressed together.
Stacking Additional Layers
The design of the "top layer" adapter parts allow stacking of additional levels for use in PLD designs and development. Each new added level provides a full set of numbered test points for monitoring. The attached data sheet gives some additional information relevant to the stacking levels.
Top Level Pin Numbering
The component pin numbering for PLCC type parts normally are numbered starting from pin 1 in the center side and counting up, counter-clockwise. Some PLCC components start with pin 1 located in the corner of the chip. The enclosed adhesive-backed number sheet which may be used by the designer in the event that the chip being worked with has pin numbering beginning at the corner. Alternately, top level adapters may be purchased with silk-screened numbering starting at the corner (or center) of the component.
Updated 01/11/03 12:00
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