METHODS AND APPARATUS TO PROVIDE TRANSIENT EVENT PROTECTION FOR CIRCUITS

摘要

Methods and apparatus to provide transient event protection for circuits are disclosed. An example apparatus includes a first clamp circuit. The first power circuit provides a first reference voltage. The first clamp circuit directs energy from a signal node to the first power circuit in response to a transient resulting in a voltage at the signal node being lower than a second reference voltage. The apparatus also includes a second clamp circuit. The second clamp circuit includes a transistor. A collector terminal of the transistor is prevented from having a lower voltage than the second reference voltage. A second power circuit provides the second reference voltage, which is lower than the first reference voltage. The second clamp circuit directs energy from the signal node to the second power circuit in response to a transient resulting in the voltage at the signal node being higher than the first reference voltage.

主权项

1. An apparatus, comprising:
a first junction isolated clamp circuit to be coupled between a first power circuit and a signal node, the first power circuit to provide a first reference voltage, and the first clamp circuit to direct energy from the signal node to the first power circuit in response to a transient event resulting in a voltage at the signal node being lower than a second reference voltage; and a second junction isolated clamp circuit to be coupled between a second power circuit and the signal node, the second junction isolated clamp circuit comprising at least a junction isolated transistor, a collector terminal of the junction isolated transistor to be prevented from having a lower voltage than the second reference voltage, the second power circuit to provide the second reference voltage, the second reference voltage to be a lower voltage than the first reference voltage, and the second clamp circuit to direct energy from the signal node to the second power circuit in response to a transient event resulting in the voltage at the signal node being higher than the first reference voltage.