Datasheet Details
| Part number | UM1661 |
|---|---|
| Manufacturer | Union Semiconductor |
| File Size | 170.16 KB |
| Description | High Efficiency Low Noise PFM Step-Up DC/DC Converter |
| Datasheet |
 UM1661 Datasheet
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General Description
The UM1661 PFM step-up DC/DC Converter drives white LEDs with a constant current to provide backlight in cell phones, PDAs, and other hand-held devices.
Key Features
- allowing series connection of the white LEDs so that the LED currents are identical for uniform brightness. An enable input can be pulsed repeatedly to adjust LEDs brightness. The fast 500kHz to 2MHz operation frequency allows for smaller capacitor and inductor. Fault condition protection uses cycle-by-cycle current limiting to sense maximum inductor current and over-voltage protection. The 0.2V low reference voltage minimizes the power loss across the current sense resistor. The converter can o.