On-chip ESD protection design for automotive vacuum-fluorescent-display (VFD) driver IC to sustain high ESD stress

A new electrostatic discharge (ESD) protection structure of high-voltage p-type silicon-controlled rectifier (HVPSCR) that is embedded into a high-voltage p-channel MOS (HVPMOS) device is proposed to greatly improve the ESD robustness of the vacuum-fluorescent-display (VFD) driver IC for automotive electronics applications. By only adding the additional n+ diffusion into the drain region of HVPMOS, the transmission-linepulsing-measured secondary breakdown current of the output driver has been greatly improved to be greater than 6 A in a 0.5-μm high-voltage complementary MOS process. Such ESD-enhanced VFD driver IC, which can sustain human-body-model ESD stress of up to 8 kV, has been in mass production for automotive applications in cars without the latchup problem. Moreover, with device widths of 500, 600, and 800 μm, the machine-model ESD levels of the HVPSCR are as high as 1100,1300, and 1900 V, respectively.