C. PIA System Setup Considerations
145
them to conduct and allowing the majority of energy to flow through them instead of
through the diode clamps. The 39 pF capacitor, in conjunction with the ferrite bead,
forms an additional low pass filter, and is entirely optional. The 1k
Ω
pullup ensures
adequate rise time on the signal. The fuse acts as additional insurance against
catastrophic events that might destroy the TransZorb and diode clamps.
ADDITIONAL INFORMATION
You can find additional design information in the
Advanced CMOS Logic Designer's
Handbook published by Texas Instruments.
