An ESD-Protected, One-Time Programmable Memory Front-End Circuit for High-Voltage, Silicon-on-Insulator Technology

An electrostatic discharge (ESD)-protected one-time-programmable (OTP) memory front-end circuit, for high-voltage (HV) applications, designed and manufactured in silicon-on-insulator (SOI) technology, is presented. The SOI technology meets HV functional-isolation and level-shifting requirements but is not suitable for advanced analog circuits. The presented OTP memory is discussed as an introduction to digital programmability in the considered technology. The memory element consists of an antifuse type structure and is implemented using a 5-V nMOS with L=1 μm and W=1.2 μm. The cell memory allows for significant area and power savings in the adopted HV technology. Conditions for this require that an efficient ESD protection will guarantee safe operation, even in the presence of a small and fragile on-chip element whose undesired burning would compromise the programming mechanism, and consequently the reliability, of the circuit. Details about the circuit design implementation of the front-end circuit for both read and write circuits and ESD protection are described with experimental results validating the proposed implementation.