RT8470应用电路 (1.2A/1A，迟滞，高亮度LED驱

RT8470应用电路 (1.2A/1A，迟滞，高亮度LED驱动器) The RT8470 is a high efficiency, continuous mode inductive step-down converter, designed for driving single or multiple series connected LEDs from a voltage source higher than the LED voltage. It operates from an input voltage of 7V to 30V and employs hysteretic control with a high side current sense resistor to set the constant output current. The RT8470 includes an output switch and a high side output current sensing circuit, which uses an external resistor to set the nominal average output current. LED brightness control is achieved with PWM dimming from an analog or PWM input signal. The RT8470 is available in a small TSOT-23-5 package or a more thermal efficient SOP-8 (Exposed Pad) package.

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Ordering Info

Note : Richtek Green products are : ► RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. ► Suitable for use in SnPb or Pb-free soldering processes.

Features

• 7V to 30V Input Voltage Range • Hysteretic Control with High Side Current Sensing • Internal N-MOSFETs with 350mW Low RDS(ON) • 1A Output Current (For TSOT-23-5 Only) • 1.2A Output Current (For SOP-8 (Exposed Pad) Only) • Up to 95% Efficiency • Typical ±3% LED Current Accuracy • Analog or PWM Control Signal for LED Dimming • 300Hz On-Board Ramp Generator • Input Under Voltage Lockout • Thermal Shutdown Protection • RoHS Compliant and Halogen Free

Application

• Automotive LED Lighting • High Power LED Lighting • Indicator and Emergency Lighting • Architectural Lighting • Low Voltage Industrial Lighting • Signage and Decorative LED Lighting

Pin Configurations

( VIEW) TSOT-23-5 SOP-8 (Exposed Pad)

Typical Applications Circuit