Analog Devices LTC4125

Description

LTC4125 Driving a 24μH Transmit Coil at 103kHz, 119kHz Frequency Limit and 41.5°C Transmit CoilSurface Temperature Limit in a Wireless Power System with LT3652HV as a 1A Single Cell LiFePO4(3.6V Float) Battery Charger at the ReceiverThe LTC®4125 is a simple and high performance monolithicfull bridge resonant driver capable of delivering over 5W ofpower wirelessly to a properly tuned receiver. The devicecontrols the current flow in a series connected transmit coilLC network to create a simple, safe and versatile wirelesspower transmitter.The LTC4125 automatically adjusts its driving frequencyto match the LC network resonant frequency. ThisAutoResonant switching allows the device to delivermaximum power from a low voltage input supply (3V to5.5V) to a tuned receiver. To optimize system efficiency,the LTC4125 employs a periodic transmit power searchand adjusts the transmission power based on the receiverload requirements. The device stops delivering powerduring a fault condition, or if a foreign object is detected.The LTC4125 also includes a programmable maximumaverage input current limit and an NTC input as additionalmeans for foreign object and overload protection. TheLTC4125 is available in a 20-lead low profile (0.75mm)4mm × 5mm QFN package.

Features

Monolithic 5W Wireless Power Transmitternn AutoResonantTM Switching Frequency Adjusts to ResonantCapacitance and Transmit Coil Inductancenn Transmit Power Automatically Adjusts to ReceiverLoadnn Input Voltage Range: 3V to 5.5Vnn Integrated 100mΩ Full Bridge Switchesnn Multiple Foreign Object Detection Methodsnn Programmable Average Input Current Limit andMonitornn NTC Input for System/Component TemperatureQualified Power Transfernn Wide Operating Switching Frequency Range:50kHz to 250kHznn Thermally Enhanced 4mm × 5mm QFN 20-Lead Package

Typical applications

• Military Sensors and Devices
• Industrial Handhelds
• Medical Equipmen
• Hermetically and/or Electrically Insulated Devices

More information

• Datasheet
• IC product information