1. Program name:

Save freewheeling diode, bridge stack package DOB special chip IC latest solution PT4558

Second, the main description

PT4558 is a high-precision non-isolated step-down LED constant current driver chip. The chip works in quasi-resonant mode and is suitable for non-isolated step-down LED constant current power supply with a full range of input voltage from 85Vac to 265Vac.

PT4558 integrates 500V power MOS, high-voltage power supply circuit, freewheeling diode and sampling circuit on a single chip, without start-up resistor and VDD capacitor, the system only needs few peripheral components, which greatly saves system cost and volume.

The PT4558 adopts a high-reliability constant current control method to achieve excellent linear regulation, load regulation and temperature characteristics. The output current mass production deviation is within +/-5%.

PT4558 provides complete protection functions: including LED short-circuit protection and over-temperature drop current protection.

PT4558 is available in SOP-4/SOP-8 package.

3. Features

*_ High voltage single chip integrated 500V power tube, high stability

*_ Internal integrated freewheeling diode

*_ No startup resistor and VDD capacitor required

*_ Quasi-resonant mode (QR) of inductor current to reduce switching losses

*_ Efficiency up to 93%_

*_ +/-5% current accuracy

*_ Excellent line regulation, load regulation and temperature characteristics

*_ LED short circuit protection

*_ Over temperature drop current protection

*_ Available in SOP-4/SOP-8 package

Fourth, the scope of application

*_ LED candle light, bulb light*_ LED down light, fluorescent light*_ Other LED lighting