Download BitsyXb User`s Manual

BitsyXb User’s Manual
For reliable ground connections, use locking washers (star or split) when securing a BitsyXb in an
enclosure. Make sure that washers do not extend beyond the limits of the pads provided.
6.1.3
Clearances
The BitsyXb has a low profile. It can fit in an enclosure with inside dimensions as thin as
0.759 inch (19.3 mm). Key clearances are as follows:
•
Highest component: 0.425 inch (10.8 mm), top
0.172 inch (4.4 mm), bottom
•
Board thickness: 0.062 inch (1.6 mm)
• Clearance over top/bottom: 0.05 inch (1.3 mm)
Note: Selection of connectors, personality board and wiring harnesses will determine height of
final assembly.
6.1.4
Production Options
The BitsyXb has a number of production options detailed throughout this manual. This section
describes options that most significantly affect the mechanical design of the board. These options
are generally available only for volume production orders.
Mating Headers on Underside of Board
The four system signal headers—J1, J3, J9 and J10—can be mounted on the underside of the
BitsyXb. This allows the BitsyXb to sit on top of another board. Note that J7 can only be
populated on top side of the BitsyXb.
Important! When the headers are placed on the underside of the board, the pin numbers will not
correspond to the signals as described in this manual. Lay out the mating board with this in mind.
PCMCIA Rails with no Ejector
In applications where the PCMCIA ejector causes clearance problems, ADS can populate a
PCMCIA slot that has rails but no ejector.
Removal of PCMCIA Header
BitsyXb systems can be built without the PCMCIA header, which can result in significant cost
savings. The base, surface-mount connector remains on the board for factory programming at
ADS and at your facility.
Connector Plating
Connectors on the BitsyXb come standard with gold plating. ADS can populate headers with
different platings as required.
Microphone Gain
The BitsyXb microphone circuitry can be configured for different gain. The most likely reason is
to support "line in" inputs (1 Vrms with no electret pull-ups), but other gain and filtering settings
are possible as well.
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ADS document # 110118-00013, preliminary