A surge clamp circuit that may be implemented with DAA circuitry to limit
the total voltage developed across one or more line side capacitors due
to charge pumping phenomenon during a multi-transient events such as
lightning strikes. The surge clamp circuit is capable of electronically
sensing a transient event (e.g., lightning strike) and of momentarily
turning on one or more components of a DAA hookswitch circuit during on
hook mode to discharge the voltage developed across one or more line side
capacitors before it reaches critical breakdown levels. The surge clamp
circuit may be configured with a clamping sensitivity selected so that
the DAA hookswitch circuitry is only activated or turned on upon
occurrence of relatively large and potentially damaging transient events,
and not upon occurrence of non-damaging transient events, such as
operational signals.