Features and Benefits
- Programmable Charge Current Up to 950mA
- Complete Linear Charger and Dual DC/DC Regulator
- Buck Converter Output Voltage from 0.6V to 5V
- No MOSFET, Sense Resistor or Blocking Diode Required
- Thermal Regulation Maximizes Charge Rate Without Risk of Overheating*
- Charges Directly from a USB Port
- Programmable Charge Current Termination
- Preset 4.2V Charge Voltage with ±1% Accuracy
- Charge Current Monitor Output for Gas Gauging*
- Automatic Recharge
- Charge Status Output
- “Power Present” Output
- 2.9V Trickle Charge Threshold
- Soft-Start Limits Inrush Current
- Low Quiescent Current Buck Converter (40µA)
- Current Mode Operation, Constant Frequency (2.25MHz)
- Low Proﬁle (5mm × 3mm × 0.75mm) DFN Package
The LTC3552 is a complete constant-current/constantvoltage linear charger with a dual DC/DC converter for single cell lithium-ion batteries. Its DFN package and low external component count make the LTC3552 ideally suited for portable applications. Furthermore, the LTC3552 is designed to work within USB power speciﬁ cations.
No external sense resistor or external blocking diode is required due to the internal MOSFET architecture. The charge voltage is ﬁxed at 4.2V and the charge current is programmed with a resistor. The charge cycle terminates when the charge current drops below the programmed termination threshold after the ﬁnal ﬂoat voltage is reached. When the input supply (wall adapter or USB supply) is removed, the LTC3552 enters a low current state dropping the battery drain current to less than 2µA. Thermal regulation maximizes charge rate without risk of overheating.
The synchronous step-down switching regulators generate adjustable output voltages from 5V down to 0.6V. The switching frequency is set at 2.25MHz, allowing the use of small surface mount inductors and capacitors.
|LTC3552||Adjustable (0.6V to 5V)|
|LTC3552-1||1.8V & 1.575V|
- Cellular Telephones, PDAs, MP3 Players
- Bluetooth Applications
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
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.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.