DatasheetsPDF.com

LTC4120 Dataheets PDF



Part Number LTC4120
Manufacturers Linear Technology
Logo Linear Technology
Description Wireless Power Receiver and 400mA Buck Battery Charger
Datasheet LTC4120 DatasheetLTC4120 Datasheet (PDF)

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 .

  LTC4120   LTC4120



Document
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 modulates the resonant frequency of a receiver tank to automatically adjust the power received as well as the power transmitted to provide an efficient solution for wirelessly charging battery-powered devices. Wireless charging with the LTC4120 provides a method to power devices in harsh environments without requiring expensive failure-prone connectors. This allows products to be charged while locked within sealed enclosures, or in moving or rotating equipment, or where cleanliness or sanitation is critical. This full featured battery charger includes accurate RUN pin threshold, low voltage battery preconditioning and bad battery fault detection, timer termination, auto-recharge, and NTC temperature qualified charging. The FAULT pin provides an indication of bad battery or temperature faults. Once charging is terminated, the LTC4120 signals end-ofcharge via the CHRG pin, and enters a low current sleep mode. An auto-restart feature starts a new charging cycle if the battery voltage drops by 2.2%. Typical Application 26.7nF Tx CIRCUITRY 6.5nF 5µH 47µH IN RUN 10µF INTVCC FREQ BOOST LTC4120 SW DHC CHGSNS NTC FAULT BAT CHRG FB GND PROG FBG 2.2µF 22nF 33µH 1.01M 1.35M Li-Ion + 4.2V T Wireless Rx Voltage/Charge Current vs Spacing 40 35 VIN 30 25 NOT CHARGING ICHARGE MAX 400 333 267 200 VIN(RX) (V) CHARGE CURRENT (mA) 20 CHARGING 15 133 67 3.01k 22µF 4120 TA01a 10 0.4 0.6 0.8 1.0 1.2 1.4 SPACING (cm) 0 1.6 1.8 4120 TA01b 4120fd For more information w.


TM4953FS LTC4120 LTC4120-4.2


@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site.
(Privacy Policy & Contact)