Fig. 3: Power management circuit and its characteristics.
From: Sweat-activated biocompatible batteries for epidermal electronic and microfluidic systems
a, Simplified block diagram of the electronic module. b, Magnified schematic of the start-up circuit. GND, circuit ‘common’ or ground; EN, enable pin of the regulator; FB, feedback node that sets the regulated voltage VE. c, Photograph of the flexible electronic module. d, Node voltages during start-up for a battery with an internal resistance of 200 Ω. VA, ideal battery voltage; VC, voltage of a typical sweat-activated battery with Rs = 200 Ω; VD, enable pin voltage of the regulator; VE, regulated system voltage; IB, battery current. e, Real-time voltage and current draw from the SAC-based battery during start-up. f, Battery voltage versus time plot acquired during continuous powering of the electronics with the SAC-based battery. Flow rate 1 µl min−1.
