US 8,149,553 B2 · Electrostatic discharge event protection for an integrated circuit

Abstract

An integrated circuit 2 is provided with a clamp transistor 20 for providing electrostatic discharge event protection. A detector circuit 28 produces a clamp control signal for switching the clamp transistor 20 to a conductive state so as to provide the electrostatic discharge protection. The detector circuit 28 also generates an electrostatic discharge event signal 36 which is distributed elsewhere within the integrated circuit 2 and controls a protection circuit element 60, 64, 44 to force a processing control signal 40, 52 of a signal processing transistor 38, 54 into a state in which the signal processing transistor 38, 54 is more resistant to electrostatic discharge damage. The signal processing transistors 38, 54 may be P-type field effect transistors associated with a receiver 14 or a transmitter 12 connected to an external signal communication line. The use of this active protection controlled by the electrostatic discharge event signal 36 permits smaller protection diodes 22, 24 to be use with such communication signal lines and/or provide for increased electrostatic discharge protection.

Claims10

Dependent claims

An integrated circuit comprising:

a power supply rail;
a ground rail;
at least one signal processing transistor controlled by a processing control signal to perform signal processing;
a clamp transistor coupled between said power supply rail and said ground rail and controlled by a clamp control signal to provide a current path between said power supply rail and said ground rail;
and
a detector circuit coupled to said power supply rail and said ground rail and generating said clamp control signal, said detector circuit being responsive to a change in voltage difference between said power supply rail and said ground rail indicative of an electrostatic discharge event to generate said clamp control signal with a value that switches said clamp transistor to a conductive state in which current flow through said clamp transistor suppresses said change in voltage difference;
wherein
said detector circuit generates an electrostatic discharge event signal when said electrostatic discharge event is detected;
and
said electrostatic discharge event signal controls a protection circuit element to force said processing control signal to a protection state in which said signal processing transistor has an increased resistance to damage from said electrostatic discharge event.

7 more elements

Dependencies are inferred from the claim text.

Electrostatic discharge event protection for an integrated circuit

Life of this patent

Electrostatic discharge event protection for an integrated circuit

Life of this patent

Abstract

Claims10