The FS8205A is a dual N-channel enhancement-mode power MOSFET designed primarily for lithium-ion and lithium-polymer battery protection applications. Manufactured by several semiconductor vendors including Fortune Semiconductor, this device integrates two low on-resistance MOSFETs within a compact surface-mount package, enabling efficient bidirectional current control for battery charging and discharging systems. The device is commonly paired with single-cell battery protection controller ICs such as the DW01A to provide overcharge, overdischarge, overcurrent, and short-circuit protection in portable electronic products. Its low drain-to-source resistance minimizes conduction losses and improves overall battery efficiency while maintaining compact PCB layout requirements. The FS8205A is widely used in battery management systems, portable consumer electronics, rechargeable battery packs, USB-powered devices, IoT hardware, and embedded power management circuits requiring reliable load switching and battery protection functionality. Engineering Specification Device Type Dual N-channel power MOSFET Transistor Technology Enhancement-mode MOSFET architecture Channel Configuration Dual independent N-channel MOSFETs Switching Characteristics Low on-resistance for efficient power switching Gate Characteristics Logic-level gate drive compatibility Current Handling Optimized for battery charge and discharge current control Power Efficiency Low conduction loss for improved battery runtime Protection System Compatibility Designed for lithium battery protection controller integration Thermal Characteristics Compact thermal-efficient surface-mount structure Package Type SOP-8 surface-mount package Mounting Style Surface mount technology Reliability Features Stable switching performance and robust load handling capability Applications Lithium-ion battery protection Battery management systems Portable electronics Rechargeable battery packs USB-powered devices Power path switching Embedded systems Consumer electronics IoT hardware Load switching circuits Manufacturer Commonly manufactured by Fortune Semiconductor and compatible vendors #commonpartslibrary #mosfet #dualmosfet #nchannelmosfet #batteryprotection #batterymanagement #powermanagement #powerelectronics #embeddedhardware #consumerelectronics #surfaceountcomponents #electronicsdesign #lithiumbattery #loadswitch #portableelectronics

Battery Multi-Function Controller IC Lithium Ion/Polymer 32-VFQFPN (5x5) L9961 is part of a complete battery pack monitoring, balancing, and protecting system for Li-Ion and Li-Polymer cells in 3, 4 or 5 series configurations. The L9961 uses a high precision ADC to provide cell voltage, stack voltage and temperature conversion via external NTC. Voltage monitoring functions are cyclically performed with a programmable loop time. Stack current is also monitored via a high accuracy CSA, continuously running and performing also Coulomb counting. Cell balancing is available and can be simultaneously activated on all cells. IC configuration and information exchange for SOC/SOH estimation are performed via I2C peripheral. The IC also integrates a dual pre-driver programmable in both HS/LS configurations for driving pack relays. L9961 also implements battery pack fuse protection to prevent fire and explosion hazards. A 3.3 V regulator with a high current capability is available for supplying pack controller and other external circuitry in both standby and normal operation modes. The IC protects the battery pack against over/under voltage conditions and monitors for over/ under temperature. It also features protection against overcurrent (both directions) and short-circuit in discharge events. Safety-relevant configurations can be stored in the internal NVM to avoid re-programming the device at each wake-up. Features • 2 μA shipment - DEEP SLEEP mode current and 5 μA standby consumption (with VREG LDO active) standby consumption (with VREG LDO active) • Integrated 3.3 V VREG LDO for supplying MCU and LEDs • Measures cell voltage (3 to 5 cells), with over/undervoltage detection and balance undervoltage protection • 12-bit voltage measurement with maximum error of ±15 mV in the [1.5 – 4.5] V range, for -40 °C < TJ < 105 °C • Measures stack voltage, with over/under voltage detection and plausibility check vs. sum of cells • Measures pack temperature via NTC, with over/undertemperature detection • Ratiometric temperature measurement with ±0.8% max. gain error in the [0.2 – VREG] V range, for -40 °C < TJ < 105 °C • Measures battery current, with Coulomb counting, overcurrent (both directions) and short-circuit in discharge protection. • 16-bit signed current measurement with 0.1% full scale error at room temperature • I 2C peripheral for device programming and data transfers over I2C bus • Cell balancing supporting up to 70 mA per cell • Dual configurable HS/LS predriver for pack relay management • Pack fuse management • Embedded NVM for configuration parameters storage • High hotplug robustness Applications • Cordless power tools • Backup energy storage systems and UPS • Light electric vehicles (e-bikes, scooters, etc.) • Portable and semi-portable equipment • Medical equipment #L9961TR #BatteryManagement #BMS #LiIonBattery #LiPoBattery #STMicroelectronics #BatteryProtection #CellBalancing #CoulombCounting #PowerManagement #EmbeddedSystems #EnergyStorage #EBike #PowerTools #ElectronicsDesign