LED driver LT3465ES6#TRMPBF ? Drives six 3.6V supply LEDs Requires no external Schottky diodes 1.2MHz switching frequency (LT3465) 2.4MHz switching frequency higher than AM broadcast band (LT3465A) VIN range: 2.7V to 16 v ■ Output voltage (MAX) = 30 v ■ Automatic soft start (LT3465) ■ Open LED protection ■ High efficiency: 81%_(LT3465) 79%_(LT3465A) typical ■ Only 0.22µf output capacitor required ■ Low profile SOT-23 (1mm) LED Driver LT3465ES6#TRMPBF

1.2MHz/2.4MHz White LED Driver Built-in Schottky in ThinSOTLED Driver LT3465ES6#TRMPBF

The LT3465 and LT3465A have internal open circuit protection circuitry. LED driver LT3465ES6#TRMPBF With the output open, VOUT is clamped at 30V when the LED is disconnected from the circuit or when the LED fails. The LT3465 and LT3465A will then switch at a very low frequency to minimize input current. VOUT and input current exhibit typical performance characteristics with the output open.

Board Layout Considerations As with all switching regulators, careful attention must be paid to the layout of the PCB and placement of components. To maximize efficiency, switch rise and fall times as short as possible. To prevent electromagnetic interference (EMI) problems, high-frequency switching paths must be properly placed. Place COUT next to the VOUT and GND pins. Always use the ground plane under the switching regulator to minimize interplane coupling. In addition, feedback to ground

Resistor R1 should be connected directly to the GND pin and not shared with any other components, ensuring a clean, noisy connection. Recommended component locations are shown in Figure 8.

Startup Input Current (LT3465A) As mentioned earlier, the LT3465A has no internal soft-start circuitry. Therefore, when driving 4 LEDs, the magnetizing inrush current can rise to about 400mA, as shown in Figure 9. The LT3465 has an internal soft-start circuit, which is recommended if inrush current must be minimized.

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The LT3465/LT3465A is a step-up DC/DC converter designed to drive up to 6 LEDs in series from a Li-Ion battery. LEDs in series provide the same LED current and do not require ballast resistors. These devices integrate Schottky diodes required external to competing devices. Additional features include output voltage limiting when the led is disconnected, onepin off and dimming control. The LT3465 has internal soft-start. The LT3465 switches at 1.2MHz, allowing the use of tiny external components. The faster LT3465A switches at 2.4MHz. Constant frequency switch, low input noise and small output capacitance. Only 0.22µf is required for 3-, 4- or 5-LED applications. The LT3465 and LT3465A are available in a low profile (1mm) 6-lead SOT-23 (ThinSOTTM) package