A Novel Low Dynamic Resistance Dual-Directional SCR With High Holding Voltage for 12 V Applications

Abstract

The excellent area efficiency of dual-directional SCRs (DDSCRs) have made them desirable for low-voltage and high-voltage applications. However, to implement the required symmetrical structure, conventional DDSCRs have to lengthen their ESD discharge path. In addition, the low holding voltage of existing DDSCRs is not suitable for high-voltage applications. In this study, a novel DDSCR with a high holding voltage and low dynamic resistance is proposed and its electrical characteristics are verified. The proposed DDSCR has two additional internal parasitic bipolar transistors compared to a conventional low-triggering voltage DDSCR (LTDDSCR). Self-gate biasing reduces latch-mode feedback between the parasitic bipolar transistors in the SCR. The device is fabricated using 0.13 um BCD processes and implements a segment layout resulting in a very low dynamic resistance of 2.2 Ω and excellent holding voltages of up to 17.2 V. The proposed DDSCR demonstrates improved reliability and area efficiency for 12 V applications.

Keywords

• Electrostatic discharge
• holding voltage
• silicon-controlled rectifier
• dual-direction
• LTDDDCR
• LDRDSCR