LTC4057-4.2 - Linear Li-Ion Battery Charger with Thermal Regulation in ThinSOT
Features
- Programmable Charge Current up to 800mA
- No External MOSFET, Sense Resistor or Blocking Diode Required
- Constant-Current/Constant-Voltage Operation with Thermal Regulation Maximizes Charge Rate Without Risk of Overheating*
- Charges Single Cell Li-Ion Batteries Directly from USB Port
- Preset 4.2V Charge Voltage with ±1% Accuracy
- Current Monitor Pin for Charge Termination
- 25µA Supply Current in Shutdown Mode
- Low Battery Charge Conditioning (Trickle Charging)
- Soft-Start Limits Inrush Current
- Available in a Low Profile (1mm) SOT-23 Package
Typical Application
Description
The LTC™4057 is a constant-current/constant-voltage linear charger for single-cell lithium-ion batteries. Its ThinSOT� package and low external component count make the LTC4057 especially well suited for portable applications. Furthermore, the LTC4057 is specifically designed to work within USB power specifications.
No external sense resistor is needed and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback prevents overheating by regulating the charge current to limit the die temperature during high power operation or high ambient temperature conditions. The charge voltage is preset at 4.2V and the charge current can be programmed externally with a single resistor.
When the input supply (wall adapter or USB supply) is removed, the LTC4057 automatically enters a low current state, dropping the battery drain current to less than 2µA. With power applied, the LTC4057 can be put into shutdown mode, reducing the supply current to 25µA.
For the standalone version (on-board charge termination) of the LTC4057, refer to the LTC4054.
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LTC4057ES5-4.2#PBF | SOT-23 | S5 | E | 05-08-1635 | Yes |
| LTC4057ES5-4.2#TRMPBF | SOT-23 | S5 | E | 05-08-1635 | Yes |
| LTC4057ES5-4.2#TRPBF | SOT-23 | S5 | E | 05-08-1635 | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC4057ES5-4.2#PBF | SOT-23 | E | $2.14 | Yes | ||
| LTC4057ES5-4.2#TRMPBF | SOT-23 | E | $2.14 | $1.43 | Yes | |
| LTC4057ES5-4.2#TRPBF | SOT-23 | E | $2.14 | $1.41 | Yes | |
| Buy Now • Request Samples | ||||||
Demo Boards
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC654A | LTC4057ES5-4.2 | Li-Ion Battery Charger, 4.25 to 6.5Vin, 600mA | $75.00 | |
| Buy Now | |||
Applications
- Wireless PDAs
- Cellular Phones
- Portable Electronics
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Design Tools
Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:
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- And More!
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
