Electrostatic Discharge Protection for Chip I/O Resistors
Original Publication Date: 1983-Apr-01
Included in the Prior Art Database: 2005-Feb-07
In a bipolar input circuit, a base diffusion region C is added to form an additional electrostatic discharge (ESD) diode to protect the p-resistor R. The subcollector is extended to the region below the added base diffusion. Since point C is closer to the input than point A, the ESD current from the input to ground (subcollector) will mostly go through the diode C. Therefore, the p-resistor R between A and B is protected from this type of ESD damage.