| Topology | Flyback Converter |
| Input voltage | 90-150 V |
| Switching frequency | 25-300 kHz |
| Output 1 | 18 V / 5 A |
| IC revision | A |
The LT3799 is an isolated flyback controller with power factor correction specifically designed for driving LEDs. The controller operates using critical conduction mode allowing the use of a small transformer. Using a novel current sensing scheme, the controller is able to deliver a well regulated current to the secondary side without using an opto-coupler. A strong gate driver is included to drive an external high voltage MOSFET. Utilizing an onboard multiplier, the LT3799 typically achieves power factors of 0.97. The FAULT pin provides notification of open and short LED conditions.
The LT3799 uses a micropower hysteretic start-up to efficiently operate at offline input voltages, with a third winding to provide power to the part. An internal LDO provides a well regulated supply for the part’s internal circuitry and gate driver.
Order Code | Datasheet | Simulation | Downloads | Status | Product series | VIN | VOut1(V) | IOut1(A) | Vaux(V) | RDC 1(Ω) | RDC 2(Ω) | RDC 3(Ω) | fswitch(kHz) | L(µH) | NPRI : NSEC : NAUX | ISAT(A) | VT(V (AC)) | L(mm) | W(mm) | H(mm) | Mount | Size | SamplesAvailability & Sample | ||
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![]() | SPECWE-OLLT Offline Flyback Transformers, 85 - 265 V (AC), 18 V | Availability – | Status Activei| Production is active. Expected lifetime: >10 years. | Product seriesWE-OLLT Offline Flyback Transformers | Input Voltage 85 - 265 V (AC) | Output Voltage 118 V | Output Current 15 A | Auxiliary Voltage18 V | DC Resistance 10.15 Ω | DC Resistance 20.008 Ω | DC Resistance 30.042 Ω | Switching Frequency 200 | Inductance300 µH | Turns Ratio6:1:1 | Saturation Current4 A | Insulation Test Voltage4500 V (AC) | Length39.6 mm | Width43.18 mm | Height30.48 mm | MountTHT | SizeETD34 | –Check availability |
| Expected Availability | Opening inventory | Quantity |
|---|---|---|
| Current Availability | – | – |