Digitally Controlled Single-inductor Multiple-output Synchronous DC-DC Boost Converter with Smooth Loop Handover Using 55 nm Process

Abstract

This paper reports on a single-inductor multiple-output step-up converter with digital control. A systematic analog-to-digital-controller design is explained. The number of digital blocks in the feedback path of the proposed converter has been decreased. The simpler digital pulse-width modulation (DPWM) architecture is then utilized to reduce the power consumption. This architecture has several advantages because counters and a complex digital design are not required. An initially designed unit-delay cell is adopted recursively for the construction of coarse, intermediate, and fine delay blocks. A digital limiter is then designed to allow only useful code for the DPWM. The input voltage is 1.8 V, whereas output voltages are 2 V and 2.2 V. A co-simulation was also conducted utilizing PowerSim and Matlab/Simulink, whereby the 55 nm process was employed in the experimental results to evaluate the performance of the architecture.

Single Inductor-Multiple Output DPWM DC-DC Boost Converter with a High Efficiency and Small Area

“…However, ADCs, digital controllers and counters, error amplifiers, external memories, reference voltage sources, large filter capacitors, and higher inductances that can lower switching frequencies require a large area. To avoid so many blocks, [18] presents smooth loop handover (SLH) technique, solving the problems of close loop performance in digitally controlled SIMO converters.…”

“…However, because of the use of a conventional delay cell in [18], the die area is very large. Also, the number of outputs of this architecture is limited up to two.…”

“…DPWM plays a key role in terms of the digital controllers that convert the digital-limiter code to duty cycles. As area is a key factor of electronic devices, it was not used for both [18] and this work. In [16], a SIMO converter was designed having a share control loop in the analog domain.…”