User's Manual

4 ELECTRICAL INTERFACE

Phone / TCU System Mechanization

4.1 Design Guidelines

4.1.1 Component Derating

4.1.1.1 Ceramic Capacitors / Parallel Plate Capacitors

Ceramic capacitors or parallel plate capacitors on power lines shall be two devices in

series to protect against capacitor shorts.

4.1.1.2 Electrolytic Capacitors

Electrolytic capacitors shall be rated at 2x the maximum voltage for a given circuit.

4.1.1.3 Tantalum Capacitors

Tantalum capacitors shall be rated at 3x the maximum voltage for a given circuit on a

power supply. They shall be rated at 2X for applications on signal lines.

Tantalum capacitors shall not be placed on circuits with currents that exceed a current of

1A or the current shall be limited to 1A.

4.1.2 Communication Pins and Unused Pins

Serial communications signals shall be terminated per manufacturers specifications.

Unused IC pins should be terminated according to manufacturer’s recommendations.

4.2 Supply Voltage

Supply Voltage (From TCU to Phone)

Min Max Units

Max

Ripple

Max