LTC3490
LTC3490 is Single Cell 350mA LED Driver manufactured by Linear Technology.
Single Cell 350m A LED Driver
Features
- 350m A Constant Current Output
- 2.8V to 4V Output pliance
- 1- or 2-Cell Ni MH or Alkaline Input
- Synchronous Rectification: Up to 90% Efficiency
- Fixed Frequency Operation: 1.3MHz
- Low Quiescent Current: <1m A
- Very Low Shutdown Current: <50µA
- Open LED Output Limited to 4.7V
- VIN Range: 1V to 3.2V
- Dimming Control
- Undervoltage Lockout to Protect Batteries
- Low Profile (0.75mm) 3mm × 3mm Thermally
Enhanced 8-Lead DD and S8 Packages
U APPLICATIO S
- Portable Lighting
- Rechargeable Flashlights
DESCRIPTIO
The LTC®3490 provides a constant current drive for 1W LED applications. It is a high efficiency boost converter that operates from 1 or 2 Ni MH or alkaline cells and generates 350m A of constant current with up to 4V of pliance. It contains a 100mΩ NFET switch and a 130mΩ PFET synchronous rectifier. The fixed switching frequency is internally set to 1.3MHz.
The LTC3490 limits the output voltage to 4.7V if the output load is disconnected. It also Features an analog dimming capability that reduces the drive current proportional to the CTRL/SHDN pin voltage. A low-battery logic output signals when the battery has dropped below 1V/cell. An undervoltage lockout circuit shuts down the LTC3490 when the battery voltage drops below 0.85V/cell. The feedback loop is internally pensated to minimize ponent count.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
Single Cell Minimum ponent LED Driver
3.3µH
1 Ni MH OR +
ALKALINE CELL
ON/OFF
350m A
CTRL/SHDN...
