Patent ID: 8503141

Claim:
A transient voltage suppressing (TVS) device supported on a semiconductor substrate comprising: a snapback circuit disposed in a semiconductor region between two oxide blocks disposed near a top surface of said semiconductor substrate wherein the semiconductor region includes alternating N-dopant and P-dopant regions disposed near the top surface of said semiconductor substrate encompassed in an N-well and adjacent P-well wherein the N-dopant regions and the P-dopant regions combined with the N-well and P-well constituting a Zener diode connected in parallel with a PNPN silicon controlled rectifier of said snapback circuit; a snapback suppressing circuit disposed in a separate semiconductor region separated from the snapback circuit by one of said oxide blocks wherein the snapback suppressing circuit comprises another set of P-dopant and N-dopant regions to function as a snapback suppressing diode in the separate semiconductor region; and the snapback circuit includes the Zener diode connected between a ground terminal and an I/O node for conducting a transient voltage current with a snapback current-voltage (I-V) characteristic upon turning on of said snapback circuit and the snapback suppressing diode connected to a Vcc terminal further conducting a current with an I-V characteristic complementary to the snapback-I-V characteristic for clamping a snapback voltage.