Easy DesignSim ™ for Energy Harvesting PMICs Spansion’s Easy DesignSim tool is an online design simulator designed to streamline the process of selecting components for energy harvesting applications. Energy harvesting is essential in converting ambient energy such as light, vibration, thermal and radio waves to electricity for a wide range of industrial, military and consumer applications. Spansion provides highly efficient buck and boost switching regulators for energy harvesting applications. It is critical to select the appropriate capacitors to manage the application’s energy in addition to an accurate estimation of the system development cost. The online Easy DesignSim tool simplifies application design by calculating the energy-budget balance while providing a recommended BOM list. This tool, which is optimized for Spansion’s product portfolio, is based on an online service from Transim Technology Corporation, which offers services around the world. To start using Easy DesignSim, go to: http://www.spansion.com/easydesignsim/ key features This online simulator easily calculates the energy-budget balance and selects the components required for circuit design. Energy-Budget Balance Calculation • After a harvester, parameters for power management, and current consumption have been selected for a system, Easy DesignSim calculates the energy-budget balance. That balance is calculated and shown in a graph, which makes it easy for users to select the input and output capacitors. Selection of Energy Harvesting Power Management IC • An appropriate energy harvesting PMIC can be selected to suit the applications, energy sources and harvesters for each industrial sector. BOM (Bill of Material) List • The BOM list and sample prices are obtained from selected parts distributors. Customers may purchase the parts online from distributors. Circuit Simulation • The simulation is quickly executed to provide the waveforms for each node in the schematic. Display of Results Summary • The results—such as the setting information, BOM list, graph for the energy-budget balance, circuit schematic, and simulation waveform— are downloadable as PDF files. Automatically Generated Circuit Schematic • The circuit schematic is automatically generated from the parameters in the energybudget-balance calculation. energy harvesting power management ics The MB39C811 and MB39C831 are energy harvesting ICs. The MB39C811 is a buck DC/DC converter and the MB39C811 is a boost DC/DC converter. The ICs have the following features. mb39c811 overview mb39c831 overview • Integrates dual-low-loss full-wave bridge rectifiers and an ultra-low-power buck DC/DC converter using the comparator control. • Integrates an ultra-low-voltage boost DC/DC converter and MPPT (Maximum Power Point Tracking), including the protection function to safely charge the Li-ion battery. • Allows the user to select from eight preset output voltages, and supplies up to 100 mA of the output current. applications Light-energy harvesting, piezoelectric-energy harvesting, electromechanical-energy harvesting, wireless HVAC sensors, standalone nano-power buck regulators. • Starts up from 0.35V using the low-voltage process and adapts applications in which a single solar cell is treated as the input. applications Solar-energy harvesting, thermal-energy harvesting, Li-ion batteries using single or multiple solar cell(s), super-capacitor chargers, portable audio players, cellular phones, eBooks, electronic dictionaries, wireless remote controllers, sensor nodes. Table 1: MB39C811 Features Table 2: MB39C831 Features ITEM DESCRIPTION ITEM DESCRIPTION INTEGRATED CIRCUIT Dual-low-loss full-wave bridge rectifier Ultra-low-power buck DC/DC converter INTEGRATED CIRCUIT MPPT (Maximum Power Point Tracking) Ultra-low-voltage boost DC/DC converter QUIESCENT CURRENT 1.5µA (no load, output in regulation) 550nA (VIN=2.5V UVLO) INPUT VOLTAGE 0.3V to 4.75V (start-up from 0.35V) INPUT CURRENT 41µA (no load, output in regulation) INPUT VOLTAGE 2.6V to 23V OUTPUT VOLTAGE OUTPUT VOLTAGE Preset output voltages 1.5V, 1.8V, 2.5V, 3.3V, 3.6V, 4.1V, 4.5V, 5.0V Preset output voltage 3.0V, 3.3V, 3.6V, 4.1V, 4.5V, 5.0V PROTECTION FUNCTION • Shunt for input protection: VIN>21V Up to 100mA pull-down • Over-current limit • I/O “Power-Good” signal detection output PROTECTION FUNCTION • Current protection function • Output voltage monitoring in the charge mode • State notification (DET0, DET1) PACKAGE QFN40 (6.0x6.0x0.85mm) PACKAGE QFN40 (6.0x6.0x0.85mm) using easy designsim The following explains the features and use of Easy DesignSim with the MB39C811 and MB39C831. The process consists of the seven steps shown in Figure 1. Figure 1: Easy DesignSim Usage Flow 1 Login & Registration 2 3 Product Selection Energy Budget Calculation & Parameter Setup 4 5 6 7 Energy Budget Result Graph Display Simulation & Circuit Schematic Generation BOM List Buy-in Part Summary & PDF Download select the pmic for energy harvesting system energy budget calculation Either the buck converter (MB39C811) or the boost converter (MB39C831) can be selected by the harvester, or selected for each application and energy source (Figure 2). Click the product part number and move to the next step. To develop an energy harvesting system, the storing energy needs to be considered because the harvester’s energy supply is low and unstable. The size of the input and output capacitors should be calculated for the energy requirements of the system. This complicated calculation is implemented in Easy DesignSim. After a harvester, parameters for power management, and current consumption have been selected for a system, Easy DesignSim calculates the energy-budget balance. The result is shown in a graph. (Refer to Figures 3, 4, 5, 6, 7, 8, and 9.) Figure 2: Easy DesignSim usage flow To set the parameters of the IC and select the input and output capacitors, click the button and the “help” window will appear. Figure 3: Energy flow in system Cloud Environmental Energy (solar, vibration, thermal, RF) Environmental Information Gateway Wireless Network Sensor Module Data Flow Harvester Piezoelectric Peltier Electromagnetic Solar Cell Harvester Block Energy Flow Energy Flow Sensor PMIC RF MCU Capacitor Capacitor Power Management Block Memory System Control Block Figure 4: Breakdown of current consumption in system Figure 8: Results of energy-budget balance in a system Figure 5: Setup for current consumption in a system Figure 9: Graph of an energy-budget balance in a system Figure 6: Setup for harvester (e.g., a solar cell) Figure 7: Setup for a power management block This graph shows the output voltage of the PMIC and the system’s minimum voltage. When the output voltage is above the system’s minimum voltage, enough energy has been stored on the input and output capacitors. Note: Spansion has verified these simulation results, based on actual measurements. However, operation of the device based on this simulation tool is not guaranteed. Circuit designers are advised to confirm operation with the actual applications. check-circuit operation The circuit schematic is automatically generated based on the parameters in the energy-budget-balance calculation (Figure 10). The simulation is executed quickly, and provides the waveforms for each node in the schematic. The parameters in the schematic are changeable. The BOM list and the sample prices are obtained, and access to the distributors provided. This estimates the BOM cost quickly and easily (Figure 12). Figure 12: BOM List Figure 10: MB39C811 circuit-schematic generation future development To supply energy to a system (e.g., a battery-less wireless sensor node), energy harvesting power management ICs need to effectively collect various kinds of environmental energy. Spansion will focus on developing more efficient, energy harvesting power management ICs with lower power consumption and lower start-up energy requirements. The company will also continue to upgrade its online simulation tools. The circuit schematic is automatically generated based on the parameters in the energy-budget calculation. The parameters are changeable. http://www.spansion.com/easydesignsim/ Figure 11: MB39C811 simulation waveform Spansion: 915 DeGuigne Drive, PO Box 3453, Sunnyvale, CA 94088-3453 USA +1 (408) 962-2500 | 1 866 SPANSION | www.spansion.com © 2014 Spansion®, the Spansion logo, MirrorBit®, MirrorBit® Eclipse™ and combinations thereof, are trademarks and registered trademarks of Spansion LLC in the United States and other countries. 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