F4901 1.1a 24v Schematic !!top!! -

When Q1 turns OFF, the magnetic field collapses. The secondary winding of T1 releases energy through D1 (Schottky diode) into output capacitor C3. The output voltage rises toward 24V.

Always consult the thermal derating curve in the manufacturer’s datasheet to ensure your hold current matches your expected environmental conditions. 5. PCB Layout Guidelines

: An open or damaged inductor (L1) can cause massive voltage spikes on the output line, causing downstream microcontrollers or sensors to reset. f4901 1.1a 24v schematic

Look for blistering, discoloration, or a cracked ceramic body on the SMD fuse itself. A charred casing indicates a catastrophic over-current event. 2. Continuity Testing

Once the fault is removed and the circuit cools down, the polymer contracts, restores the conductive path, and resets automatically. Topology B: Surface Mount Device (SMD) Fast-Acting Fuse When Q1 turns OFF, the magnetic field collapses

Do not use in 36V or 48V topologies; ideal for industrial 12V/24V systems.

Help you find the for specific manufacturers of the F4901. Always consult the thermal derating curve in the

: Always measure the resistance across a suspected blown fuse in-circuit. A good fuse will read near 0 ohms. If you read several hundred ohms, it is likely conducting through a parallel path. Do not remove a fuse from the board to test it; test it in-circuit first.

The most common failure point in designs utilizing the F4901 schematic is ignoring . Because PPTCs rely on thermal energy to trip, their performance is heavily dependent on ambient room temperature.

High Voltage Input (48V max) ----+----[Input Cap]----+----[F4901 VIN Pin] | | +----[Startup Resistor]---+ | [Freewheeling Diode]---[SW Pin (F4901)] | +----[Inductor L1]-------> Output (+24V) | [Output Cap] ---+----[FB Resistor Divider] | GND