Eiaj-tqfp locking Clips Product Description




Дата канвертавання27.04.2016
Памер23.6 Kb.

EIAJ-TQFP Locking Clips




Product Description

TQFP metric locking test clips are offered in several sizes. These clips allow the user to attach a test instrument such as an emulator or logic analyzer to a surface mounted Thin Quad Flat Pack (TQFP) chip. (Sometimes also referred to as SQFP.)


The locking feature provides additional security for testing with the board under test in the vertical or horizontal position. See the product data sheet or the ET online catalog for ordering information.
The clip locates the corners of the chip body with four corner locator lugs to provide preliminary location for the contacts to accurately locate the chip leads. Secondary alignment is provided by the square or rectangular recess that mates with the top half of the chip body.
It is essential for proper operation of the clip for the chip to have straight and undamaged leads. Any bent leads can lead to improper fit and possible damage to the chip leads.
Specifications




Electrical

Operating Voltage


30 VDC


(60 V peak AC)

Current

0.5 A max.

Insulation


100 MΩ min.


Capacitance


2 pF max.


Self Inductance


40 nH max.


Contact Resistance


100 mΩ max.


Bandwidth

(-3db)

150 MHz typ.


Crosstalk


-19 dB @


75MHz typ.


Operation



Installation


  • Step 1 Turn off power to the system under test.




  • Step 2 Make sure all of the leads of the chip are straight and not covered by any contaminating material such as solder flux dust, oil or conformal coatings.



CAUTION


To avoid damage to the test clip and to the chip under test, do not install the clip on any device that has bent, damaged or misaligned leads.


  • Step 3 Make sure that there is room around the chip for the clip to be seated completely on the board.




  • Step 4 Slide the corner guides over the corners of the chip body and make sure that the clip is parallel to the chip and that all four sides are even and aligned with the clip guides. Press down on the clip with even, firm pressure.



CAUTION


The clip must be parallel to the chip. Do not force the clip over the chip unevenly. You may damage the chip or the clip contacts. All four sides of the clip must slide over the chip leads at the same time. If there is any doubt, remove the clip and try again.
Visually inspect the fit of the clip on the chip leads to assure proper fit. It is possible to check the alignment of the clip to the chip by measuring the resistance on the circuit board between VCC and GND. With the power off, use an ohmmeter to probe between VCC and GND on the board. If the resistance is less than what is nominal for the system, remove the clip and measure the resistance on the system again. Do not apply power until this measurement confirms circuit integrity.


  • Step 5 Press down on the locking button and turn 1/4 turn clockwise. Make sure the locking fingers are completely inserted under the chip corners. If there are any obstructions, improper operation may result.




  • Step 6 Attach the test instrument to the clip with care. Do not apply force to dislodge the clip from the chip.




  • Step 7 Apply power to the system.



CAUTION

Use standard anti-static precautions such as a ground strap, when using this product around static sensitive components.
When using these clips with cables or pods attached to long cables, take care that the cables do not apply any mechanical force to the clip while the clip is attached to the system and power is applied. Whenever possible, tie cables to a mechanical support to isolate the clip from any forces.
Although this clip is designed to operate with the board under test either horizontal or vertical, it is best to provide some means of supporting the weight of cable or wires attached to the clip.
Removal


  • Step 1 Turn off power to the system under test.




  • Step 2 Remove any connecting wires or cables.




  • Step 3 Press down on the center button and turn 1/4 turn counter-clockwise. Allow knob to move up. Hold clip by the sides, and pull straight up.



Maintenance



Inspection
Inspect for bent, broken or damaged contacts. Contacts that are bent will show easily with visual inspection. A thin coating of solder on the contact surface will not affect operation. Excessive solder coating or foreign material that extends past the width of the contact can cause improper operation.
Make sure that there is no foreign material in the chip cavity that would prevent the clip from fully engaging the chip. Slightly bent contacts may not be straightened. Contact the factory for replacement procedure.
Examine the corner guides for excessive wear or abrasion. Any material that is scraped off the guide may prevent proper connection.
Cleaning
Remove foreign material from the lower contacts and locking fingers with low pressure compressed air. Fuzz or lint may be picked out with fine tip tweezers.
Do not use chemicals or abrasive cleaners on the contacts or plastic surfaces.


База данных защищена авторским правом ©shkola.of.by 2016
звярнуцца да адміністрацыі

    Галоўная старонка