LTC4121
LTC4121-4.2
RECOMMENDED FOR NEW DESIGNS
40V 400mA Synchronous Step-Down Battery Charger
- Part Models
- 8
- 1ku List Price
- Starting From $3.98
Overview
- Wide Input Voltage Range: 4.4V to 40V
- Temperature Compensated Input Voltage Regulation for Maximum Power Point Tracking (MPPT)
- Adjustable Float Voltage 3.5V to 18V (LTC4121)
- 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
The LTC4121 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 maintains maximum power transfer 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%.
Applications
- Handheld Instruments
- Solar Powered Devices
- Industrial/Military Sensors and Devices
Documentation
Data Sheet 1
User Guide 1
Brochure 1
Product Selector Card 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| LTC4121EUD#PBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC4121EUD#TRPBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC4121EUD-4.2#PBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC4121EUD-4.2#TRPBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC4121IUD#PBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC4121IUD#TRPBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC4121IUD-4.2#PBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) | ||
| LTC4121IUD-4.2#TRPBF | 16-Lead QFN (3mm x 3mm x 0.75mm w/ EP) |
This is the most up-to-date revision of the Data Sheet.
