A Fully Integrated 1 GHz 8A Imax Step-Down and Step-Up Switched Capacitor Voltage Regulator in 3 nm FinFET Technology Featuring Auto Mode Transition

This paper presents a fully integrated continuous-scalable conversion-ratio (CSCR) switched-capacitor voltage regulator (SCVR), capable of supporting a wide range of voltage conversion ratios and high load current for SOCs used in computing and other applications. This design can achieve both step-down and step-up voltage conversion and has phase-merged turbo modes to deliver higher output current. It can autonomously and dynamically transition between step-down and step-up modes based on conversion ratio and between regular and turbo modes depending on load current. This SCVR is designed using Intel’s 3nm FinFET technology and is capable of an output voltage range of 0.5V-1.2V from an input of 1.1V. Furthermore, the input voltage can be in the range 1.1-1.3V for the same output voltage range. It can deliver up to 8A of load current at a 1GHz flying capacitor switching frequency and exhibits a peak efficiency of 88%. This design minimizes the added die area for the converter by implementing the flying capacitors over the load domain and achieves a maximum active area power density of 14W/mm2. The converter uses a fast asynchronous voltage droop detector, in combination with auto-transition to turbo modes, to achieve excellent transient response-an output voltage droop of 37.5mV was measured for a fast (100ps) load current step from 0.1A to 6A. It also features configurable maximum switching frequency reduction and clock interleaving to achieve an output voltage ripple of 20mV.