LTC4120

LTC4120/LTC4120-4.2 Wireless Power Receiver and 400mA Buck Battery Charger Features n Dynamic Harmonization Control Optimizes Wireless Charging Over a Wide Coupling Range n Wide Input Voltage Range: 12.5V to 40V n Adjustable Float Voltage: 3.5V to 11V n Fixed 4.2V Float Voltage Option: LTC4120-4.2 n 50mA to 400mA Charge Current Programmed with a Single Resistor n ±1% Feedback Voltage Accuracy n Programmable 5% Accurate Charge Current n No Microprocessor Required n No Transformer Core n Thermally Enhanced, Low Profile 16-Lead (3mm × 3mm × 0.75mm) QFN Package Applications n Handheld Instruments n Industrial/Military Sensors and Devices n Harsh Environments n Portable Medical Devices n Physically Small Devices n Electrically Isolated Devices L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Description The LTC®4120 is a constant-current/constant-voltage wireless receiver and battery charger. An external programming resistor sets the charge current up to 400mA. The LTC4120-4.2 is suitable for charging Li-Ion/Polymer batteries, while the programmable float voltage of the LTC4120 accommodates several battery chemistries. The LTC4120 uses a Dynamic Harmonization Control (DHC) technique that allows high efficiency contactless charging across an air gap. The LTC4120 regulates its input voltage via the DHC pin. This technique mo...