Microchip Technology MCP651, Руководство пользователя

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MCP651 Input Offset Evaluation Board User’s Guide
DS51834A-page 22
©
2009 Microchip Technology Inc.
3.3.3 Single Op Amps in SOIC-8 Package
Solder onto the SOIC-8 pad shown in Figure 3-2. Pin 1 is on the top left (next to the U1
label). To avoid soldering and de-soldering many times, for slower parts, it may be
better to use the option discussed in
Section 3.3.5 “Other Single Op Amps” .
3.3.4 Single Op Amps in PDIP-8 Package
Remove the original SOIC-8 packaged part. Solder a DIP-8 IC Socket in the PDIP-8
location shown on Figure 3-2; this makes it easy to change PDIP-8 parts. It also is
helpful for parts for other package and pinout options; see
Section 3.3.5 “Other
Single Op Amps” . Figure 3-3 shows this board after the DIP-8 IC socket has been
installed.
FIGURE 3-3: PCB with SOIC-8 Part Removed and DIP-8 IC Socket Installed.
The socket may not work well in two cases (solder directly to the PCB instead):
• Very fast op amps (i.e., GBWP > 100 MHz)
• Very accurate op amps (i.e., V
OST
< ±50 µV)
3.3.5 Other Single Op Amps
With a DIP-8 IC Socket on the evaluation board (see Section 3.3.4 “Single Op Amps
in PDIP-8 Package” ), it is relatively easy to adapt the MCP651 Input Offset Evaluation
Board to many other op amps. An adaptor board is stacked on top using headers that
solder to the adaptor board, using PDIP-8 through holes, and are inserted into the
DIP-8 socket on the evaluation board. The adaptor board can accommodate:
• Different packages
• Different pinout options (can be dealt with on the adaptor board)
• Parts with multiple op amps
The adaptor boards approach may not work well in two cases:
• Fast op amps (i.e., GBWP > 10 MHz); adding bypass capacitors to the adaptor
board may help
• Accurate op amps (i.e., V
OST
< ±50 µV)