The LT3486 is a dual step-up DC/DC converter specifically designed to drive up to 16 White LEDs (8 in series per converter) at constant current from a single Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness. The two independent converters are capable of driving asymmetric LED strings. The dimming of the two LED strings can be controlled independently via the respective CTRL pins. An internal dimming system allows the dimming range to be extended up to 1000:1 by feeding a PWM signal to the respective PWM pins. The LT3486 operating frequency can be set with an external resistor over a 200kHz to 2.5MHz range. A low 200mV feedback voltage (±3% accuracy) minimizes power loss in the current setting resistor for better efficiency. Additional features include output voltage limiting.
The LT3486 is a dual step‑up DC/DC converter designed to drive up to 16 white LEDs (8 per converter) from a single Li‑ion cell or a 12 V supply. It provides independent control of each LED string through separate CTRL pins and can extend the dimming range to 1000:1 using PWM pins. The device operates with a fixed frequency up to 2.5 MHz and offers a low shutdown current below 1 pA.
Typical applications include notebook PC displays, LED camera lights for cell phones, car dashboard lighting, and avionics displays. The part is offered in compact 16‑pin DFN and thermally enhanced TSSOP packages, with built‑in over‑voltage and open‑circuit protection for reliable operation.
| Input Voltage Range | 2.5 V to 24 V |
|---|---|
| PWM Dimming Range | 1000:1 |
| LED Current Programming Accuracy | ±3 % |
| Maximum Duty Cycle | up to 96 % |
| Switch Current Limit | 1.3 A |
| Over‑Voltage Protection Clamp | 36 V (typ) |
| Package Options | 16‑Pin DFN (6 mm × 3 mm × 0.75 mm) and 16‑Pin TSSOP |
It can drive up to 16 white LEDs, with 8 LEDs per independent converter.
Each LED string can be dimmed independently via its CTRL pin, and the PWM pins can extend the dimming range to 1000:1.