Varnum S Holland

Title: Varnum S. Holland: Innovator in Semiconductor Technology

Introduction

Varnum S. Holland is a notable inventor based in Amherst, NH (US), recognized for his contributions to semiconductor technology. He holds a total of four patents, showcasing his innovative approach to electrical engineering and circuit design.

Latest Patents

One of his latest patents is the Transformer Isolated Drive Circuit. This invention features a transformer that is driven with a high-frequency Pulse Width Modulated (PWM) signal. The design allows the PWM carrier to supply the necessary power for high gate current pulses, while different duty cycles control the 'on' or 'off' state of the power device. The circuit prevents transformer saturation by sensing primary current and returning it to zero once per PWM cycle. This innovation enables fast 'on-off' switching of large N- or P-channel devices without the need for auxiliary power supplies. Additionally, it includes provisions for rapid output current limiting, essential for short circuit protection.

Another significant patent is the Integrated Circuit Under-Voltage Lockout. This low voltage lockout circuit provides a lockout signal when the internally generated reference voltage is insufficient. The invention produces a reference voltage by passing a constant current through a reference voltage element, such as a zener diode. It detects insufficient reference voltage caused by low power supply input voltage by sensing the saturation of the constant current source. The resulting lockout signal indicates the minimum usable power supply input voltage, enhancing the reliability of integrated circuits.

Career Highlights

Varnum S. Holland has worked with several companies throughout his career, including Unitrode Corporation and Solid State Chargers Research and Development Limited. His experience in these organizations has contributed to his expertise in semiconductor technology and circuit design.

Collaborations

He has collaborated with notable professionals in the field, including Claudio De Sa E Silva and Jeffrey D. Putsch. These collaborations have likely enriched his work and led to further advancements in his inventions.

Conclusion

Varnum S. Holland's innovative contributions to semiconductor technology, particularly through his patents, demonstrate his significant impact on the field. His work continues to influence the development of efficient and reliable electronic circuits.