A P&O MPPT With a Novel Analog Power-Detector for WSNs Applications

This brief presents a perturb and observe (P&O) maximum power point tracking (MPPT) with a novel analog power detector for wireless sensor nodes (WSNs) applications. The proposed analog power detector can judge the output power variation only by the voltage measurements, which eliminates the use of current measurements or microcontroller unit (MCU), so that its complexity and power consumption are greatly reduced. The proposed P&O MPPT circuit with the analog power detector has the advantages of simple structure, low power consumption, and high power efficiency. The proposed MPPT is used in a discontinuous conduction mode (DCM) buck-boost converter with fixed duty cycle to improve the efficiency performance. This design has been implemented in a 0.18 mu m CMOS process occupying an active area of 0.98x0.9mm(2). The input voltage range can be from 2V to 7.2V. The peak conversion efficiency and peak tracking efficiency are 86% and 98% respectively, with power consumption about 9 mu W.