Multimode high-resolution DPWM for RF class-D amplifiers

Abstract

This paper describes a multimode high-resolution digital pulse width modulator. This modulator, based on a novel hybrid structure, not only has a programmable duty cycle but also realizes phase modulation. A 576 ps pulse resolution is achieved based on a 13.56 MHz switching frequency for near field communication. Fabricated in a SMIC 0.18-μm EEPROM CMOS process, the total area of modulator is only 130 × 180 μm2. Measurement results validate the multi-mode modulation function and high pulse resolution.