A 100 MHZ Above 80% Efficiency Multi-Phase Switching Regulator
Performance per Watt has become increasingly important metric for microprocessors used in today’s mobile
devices. Dynamic voltage frequency scaling (DVFS) is widely used approach to improve on the performance/Watt. In this
paper, integrated voltage regulator (IVR) type multiphase buck converter switching at 100 MHz providing a maximum load
current of 2.0 A is presented, useful in DVFS applications. To realize such high switching frequency converter, all the
components including the low-pass filter passives namely inductor and capacitor where made on-chip. In-house magnetic
core based inductor for higher inductive density and MOSFET based capacitor are used to realize ASIC with no components
on board. Thus, eliminating bottlenecks arising from bond-wire parasitic restricting the response time to few 10s of μs range.
The converter output voltage settles within 5-7 clock cycles roughly around 50-70 ns timescale for a step load current change
of ΔIL = 1.0 A. The converter output ripple is also curtailed to few 10s of mV mainly through ripple cancellation using
multiphase, plus lower inductor current ripple on account of operating at high switching frequency.
Keywords - Multiphase Buck Converter, Switching Mode Power Supply, Integrated Voltage Regulator, Dynamic Voltage
Frequency Scaling, Voltage-mode Controller.