Overview
Features and Benefits
- Wide Input Voltage Range: 9V to 32V (40V Absolute Maximum)
- Programmable Charge Current: Up to 2A
- User-Selectable Termination: C/10 or Onboard Termination Timer
- Dynamic Charge Rate Programming/Soft-Start Pin
- Programmable Input Current Limit
- 1MHz Fixed Frequency
- Average Current Mode Control
- 0.5% Float Voltage Accuracy
- 5% Charge Current Accuracy
- 2.5% C/10 Detection Accuracy
- NTC Resistor Temperature Monitor
- Auto-Recharge at 97.5% Float Voltage
- Auto-Precondition at <70% Float Voltage
- Bad Battery Detection with Auto-Reset
- Binary Coded Open-Collector Status Pins
- 3mm × 3mm DFN-12 or MSOP-12 Package
Product Details
The LT3650 is a complete monolithic 2-cell Li-Ion/Polymer battery charger that operates over a 9V to 32V input voltage range (11.5V minimum start-up voltage). The LT3650 provides a constant-current/constant-voltage charge characteristic, with maximum charge current externally programmable up to 2A, set using an external current sense resistor. A precondition feature trickle-charges a low voltage battery, and bad-battery detection provides a signal and suspends charging if a battery does not respond to preconditioning.
The LT3650 can be configured to terminate charging when charge current falls to C/10, or one-tenth the programmed maximum current. Once charging is terminated, the LT3650 enters a low current (85μA) standby mode. An auto-restart feature starts a new charging cycle if the battery voltage drops 2.5% from the float voltage, or if a new battery is inserted into a charging system.
The LT3650 contains a user-programmable internal safety timer (typically set to a three hour full cycle time). The IC can be configured to use this internal timer if a time-based termination scheme is desired in which charging can continue below C/10 until a desired time is reached.
The LT3650 is available in a low profile (0.75mm) 3mm × 3mm 12-pin DFN and 12-pin MSOP packages.
Float Voltage | |
LT3650-4.1 | 4.1V |
LT3650-4.2 | 4.2V |
LT3650-8.2 | 8.2V |
LT3650-8.4 | 8.4V |
Applications
- Industrial Handheld Instruments
- 12V to 24V Automotive and Heavy Equipment
- Desktop Cradle Chargers
- Notebook Computers
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.
Evaluation Kits (2)
Documentation
Reliability Data (1)
Application Notes (1)
Evaluation Kit Manuals (1)
Tools & Simulations
LTspice
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.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

LTspice Simulations
Models for the following parts are available in LTspice:
Reference Materials
Product Selector Card (1)
Press Releases (1)
Technical Articles (1)
Design Resources
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.
PCN-PDN Information
Support & Discussions
LT3650-8.2 Discussions
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.