# AEM13921-QFN (Component) ## Description Ultra Efficient Dual Sources Energy Manager with Ratio/Constant Voltage Regulation, Regulated Buck Output and 5 V Charger, 120 mV, 135 mA The AEM13921 is a fully integrated and compact power management circuit that extracts DC power from two harvesting sources to store energy in a rechargeable storage element and supply an application circuit. A 5 V input can also be used to charge the storage element (e.g., if it gets depleted). This compact and ultra-efficient PMIC allows for extending battery lifetime and eliminating the primary energy storage in a large range of applications. Both sources implement Maximum Power Point Tracking (MPPT) based on open-circuit voltage ratio as well as constant source voltage regulation features, allowing for harvesting the maximum power available from each source to charge the storage element. With its unique cold-start circuit, it can start operating with an input voltage as low as 275 mV (min. 1.5 µW power). The configurable protection thresholds prevent overcharging and overdischarging the storage element. No external components are required to set those thresholds. The thermal monitoring prevents charging and discharging the storage element outside a configurable temperature range. The Average Power Monitoring (APM) allows the application circuit to get an estimate of the energy harvested from each source to the battery and from the battery to the application circuit. A shipping mode is available to avoid charging and discharging the storage element during shipping or storage. A buck regulator with selectable output voltage allows an application circuit to be supplied with high efficiency. I²C communication allows users to control every setting of the AEM13921 from the application circuit MCU. Features and Benefits Dual sources inputs - Boost operation optimized for each source. - Conversion efficiency above 90 % on each source. - Harvests from 120 mV after cold start. - Simultaneous harvesting from both sources. - Up to 135 mA current extracted from the harvester. Maximum Power Point Tracking - Both sources configurable to constant voltage mode or to open-circuit voltage ratio mode. - Optimal harvesting from a multiple combinations of harvesters (PV cells, RF, vibration, pulsed sources...). Cold start from 275 mV / 1.5 µW input - Startup at ultra-low power from each harvesting source input. Configurable overdischarge & overcharge protection - Supports various types of rechargeable storage elements (LiC, Li-ion, LiPo, Li-ceramic pouch...). Regulated output for application circuit - Buck regulator conversion efficiency up to 96 %. - Selectable output voltage between 0.6 V and 3.3 V. - Output current up to 100 mA. Thermal monitoring - Storage element protection against overtemperature and under-temperature during charging and discharging, independently. Average Power Monitoring - Provides data to determine how much energy has been transferred to the storage from each source and from the 5 V charger, as well as the energy drained from the storage to supply the application circuit. System configuration by GPIO or I²C communication - All settings dynamically configurable through GPIO or I²C (Fast Mode Plus). - System data available through I²C. Shipping mode - Storage element charge and discharge disabling during shipment. External 5 V charging capability - Extra charging input for 5 V power supplies. - Configurable CC and CV modes (max. 135 mA). - Provides a fast charging alternative when no source is available for a long time. #AEM13921 #EnergyHarvesting #PowerManagementIC #PMIC #MPPT #BatteryCharging #EnergyAutonomous #IoT #WirelessSensor #IndustrialMonitoring #EmbeddedSystems #QFN #epeas #LowPowerDesign ## Component Details - **Owner:** adrian95 - **Created:** 6/7/2026 - **Last Updated:** 6/7/2026 - **Visibility:** Public - **Manufacturer Name:** E-PEAS - **Datasheet URL:** https://e-peas.com/documents/AEM13921/DS-AEM13921.pdf - **Package or Case Code:** QFN - **Symbol Style:** parametric-v1 - **Part Type:** Linear Regulator - **License:** https://creativecommons.org/licenses/by/4.0/ - **Manufacturer Part Number:** AEM13921-QFN ## Distributor Pricing (qty 1) *Pricing shown for quantity 1. For price breaks and other quantities, open in Flux.* | Distributor | Unit Price (qty 1) | Stock | |------------|--------------------|-------| | [Mouser](https://www.mouser.com/ProductDetail/e-peas/AEM13921-QFN?qs=FmjOKN4Os84WSudi%2FoqerA%3D%3D) | $4.50 | 682 | - **Part Type:** Other - **MPN:** AEM13921-QFN - **Mount Type:** Base - **Package / Case Code:** QFN - **Pin Count:** 41 ## Pins | Pin | Name | Type | |-----|------|------| | 6 | BUFSRC2 | | | 2 | SRC1 | | | 15 | 5V_IN | | | 13 | STO | | | 3 | BUFSRC1 | | | 12 | SWBUCK | | | 28 | VINT | | | 1 | ZMPP | | | 4 | SWBOOST1 | | | 7 | SRC2 | | | 5 | SWBOOST2 | | | 14 | LOAD | | | 17 | VDDIO | | | 38 | TH_MON | | | 24 | STO_CFG[2] | | | 16 | 5V_IMAX | | | 36 | LOAD_CFG[0] | | | 34 | SRC2_CFG[1] | | | 29 | SRC1_CFG[2] | | | 10 | LOAD_CFG[1] | | | 32 | SRC2_MODE | | | 39 | SRC2_CFG[4] | | | 40 | TH_REF | | | 35 | SRC2_CFG[2] | | | 26 | SRC1_CFG[0] | | | 37 | SRC2_CFG[3] | | | 23 | STO_CFG[1] | | | 27 | SRC1_CFG[1] | | | 22 | STO_CFG[0] | | | 31 | SRC1_CFG[4] | | | 33 | SRC2_CFG[0] | | | 30 | SRC1_CFG[3] | | | 25 | SRC1_MODE | | | 11 | LOAD_CFG[2] | | | 19 | SCL | | | 18 | IRQ | | | 20 | SDA | | | 8 | SHIP_MODE | | | 21 | ST_STO | | | 9 | ST_LOAD | | | 41 | GND | | --- *Generated from [https://www.flux.ai/adrian95/aem13921-qfn](https://www.flux.ai/adrian95/aem13921-qfn)*