PT4205E89E

PT4205 is a continuous inductor current conduction mode buck constant current source designed to drive one or more series-connected LEDs. Its input voltage ranges from 5V to 30V, with a 200mV ±3% reference voltage. The output current is set via an external resistor, with a maximum of 1.2 amperes. Depending on the input voltage and external components, the PT4205 can drive LEDs with power up to tens of watts. The PT4205 integrates a power switch and uses high-side current sensing to set the average LED current. The DIM pin accepts both analog dimming and wide-range PWM dimming. A built-in over-temperature soft protection function automatically reduces the LED current when the temperature is too high, improving system reliability and avoiding flickering issues that may occur during high-temperature operation. The PT4205 is available in SOT89-5 and ESOP8 packages.

Applications

• Low-voltage LED spotlights (halogen lamp replacement)
• Automotive LED lighting
• LED backup lights
• LED signal lights

Key features

• Minimal external components
• Input voltage range: 5V to 30V
• Maximum output current up to 1.2A
• 3% output current accuracy
• Multiplexed DIM pin for LED on/off switching, analog dimming, and PWM dimming
• Natural protection against LED open circuit
• Peak efficiency up to 97%
• Adjustable output constant current control
• Over-temperature automatic current reduction for soft protection
• ESOP8 package with enhanced thermal dissipation for high-power driving