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 Categories
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 & Resources
-
R541 Reliability Data3/26/2018PDF17 K
-
DC1473A - Demo Manual9/24/2009PDF397K
-
20V Battery Gas Gauge10/22/2013PDF522K
Tools & Simulations
LTspice
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.