Justin Shi

A robust digital DC-DC converter with rail-to-rail output range in 40nm CMOS

The growing complexity and small form factors of hand-held consumer electronics are the driving force of more integration. This increases the need for truly embedded DC-DC converters in advanced processes. Traditional analog DC-DC converter architectures do not fit well with low supply voltages. Digital architectures are attractive, but require an analog-to-digital converter (ADC), which can be challenging to design [1–3].

Practical Considerations for a Digital Inductive-Switching DC/DC Converter With Direct Battery Connect in Deep Sub-Micron CMOS

This paper describes design considerations for a digital inductive-switching DC/DC converter suitable for direct battery connection in a deep sub-micron CMOS process. Digital control techniques and robust circuit design methods take advantage of the advanced process technology while avoiding the barriers to direct battery connection and high efficiency, high power density voltage conversion. The approach is verified on a prototype converter, implemented in 40 nm standard bulk CMOS. The design achieves a peak efficiency of 95% for an input range of up to 5.5 V. The transient response is optimized for typical mobile SoC operating conditions and achieves step response times as fast as 35 μs/V under load.

A wide-range DC/DC converter with 2 nd order digital compensation and direct battery connection in 40nm CMOS

This paper presents a digital DC-DC converter with 2nd order compensation and direct battery connect capability in 40nm CMOS. A combination of circuit and process technology is used to achieve an input range up to 5.5V with peak efficiencies of 95%. It also outlines an approach to optimize a control loop based on a sigma-delta ADC and higher order digital filter, which is demonstrated on a prototype achieving step response times under load below 38µs/V.