Datasheet Linear Technology LTC4121IUD#TRPBF
40 V 400 mA Synchronous Step-Down Battery Charger.
A constant- current/constant-voltage 400 mA charger for Lithium-Ion, LiFePO4 and lead-acid batteries. The LTC4121’s high efficiency, synchronous step-down topology accepts a wide 4.4 V to 40 V input.
- Wide Input Voltage Range: 4.4 V to 40 V
- Adjustable Battery Charge Voltage: 3.5 V to 18 V
- Temperature Compensated Input Voltage
- Regulation for Maximum Power Point Tracking (MPPT)
- Fixed 4.2 V Charge Voltage Option: LTC4121-4.2
- High Efficiency: Up to 94%
- 50 mA to 400 mA Programmable Charge Current
- ±1% Feedback Voltage Accuracy
- Programmable ±5% Accurate Charge Current
- Thermally Enhanced, Low Profile (0.75mm) 16-Lead 3 mm × 3 mm QFN Package
- Download » Datasheet, PDF, 355 Kb
LTC4121/LTC4121-4.2 40V 400mA Synchronous Step-Down Battery Charger FeaTures
n n n DescripTion
The LTC®4121 is a 400mA constant-current/constantvoltage (CC/CV) synchronous step-down battery charger. In addition to CC/CV operation, the LTC4121 regulates its input voltage to a programmable percentage of the input open-circuit voltage. This technique enables maximum power operation with high impedance input sources such as solar panels. An external resistor programs the charge current up to 400mA. The LTC4121-4.2 is suitable for charging Li-Ion/ Polymer batteries, while the programmable float voltage of the LTC4121 is suitable for several battery chemistries. The LTC4121 and LTC4121-4.2 include an 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 LTC4121 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%. n n n n n n Wide Input Voltage Range: 4.4V to 40V Adjustable Float Voltage (3.5V to 18V): LTC4121 Temperature Compensated Input Voltage Regulation for Maximum Power Point Tracking (MPPT) Fixed 4.2V Float Voltage Option: LTC4121-4.2 High Efficiency: Up to 95% 50mA to 400mA Programmable Charge Current ±1% Feedback Voltage Accuracy Programmable 5% Accurate Charge Current Thermally Enhanced, Low Profile (0.75mm) 16-Lead (3mm × 3mm) QFN Package applicaTions
n n n Handheld Instruments Solar Powered Devices Industrial/Military Sensors and 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. Typical applicaTion
High Efficiency, Wide Input Voltage Range Charging with LTC4121
IN 10µF 10k RUN MPPT LTC4121 SW CHGSNS BAT 1.96M FB PROG FREQ RPROG GND FBG 787k 22µF VIN VBAT + 200mV TO 40V INTVCC BOOST 22nF EFFICIENCY (%) SLF6025T-470MR48 2.2µF 95 LTC4121 Efficiency vs VIN at VFLOAT = 8.4V
97 200mA, PROG = 6.04k 400mA, PROG = 3.01k 93 + 91 +
Li-Ion 89 VBAT = 8.3V 5 10 15 20 25 VIN (V) 30 35 40 87
4121 TA01a 4121 TA01b For more information www.linear.com/LTC4121 1 4121f LTC4121/LTC4121-4.2 absoluTe MaxiMuM raTings
(Note 1) IN, RUN, CHRG, FAULT, MPPT . 0.3V to 43V BOOST . VSW 0.3V to (VSW + 6V) SW (DC) . 0.3V to (VIN + 0.3V) SW (Pulsed <100ns) .1.5V to (VIN + 1.5V) CHGSNS, BAT, FB/BATS ...
Other Names: LTC4121IUDTRPBF, LTC4121IUD TRPBF
Docket:LTC4121/LTC4121-4.2 40V 400mA Synchronous Step-Down Battery Charger FeaTures
n n n DescripTion
The LTC®4121 is a 400mA constant-current/constantvoltage (CC/CV) synchronous step-down battery charger. In addition to CC/CV operation, the LTC4121 regulates its input voltage to a programmable percentage of the input open-circuit voltage. This technique enables ...
- Series: LTC4121 / LTC4121-4.2 (8)