30V 1A LED driver with internal switch
General Description
The CL6807 is a continuous mode inductive step-down converter, designed for driving single or multiple series connected LEDs efficiently from a voltage source higher than the LED voltage. The device operates from an input supply between 7V and 30V and provides an externally adjustable output current of up to 1A. Depending upon supply voltage and external components, this can provide up to 35 watts of output power. The CL6807 includes the output switch and a high-side output current sensing circuit, which uses an external resistor to set the nominal average output current. Output current can be adjusted above, or below the set value, by applying an external control signal to the 'ADJ' pin. The ADJ pin will accept either a DC voltage or a PWM waveform. Depending upon the control frequency, this will provide either a continuous or a gated output current. The PWM filter components are contained within the chip.
The PWM filter provides a soft-start feature by controlling the rise of input/output current. The soft-start time can be increased using an external capacitor from the ADJ pin to ground. Applying a voltage of 0.5V or lower to the ADJ pin turns the output off and switches the device
into a low current standby state.
Features
Simple low parts count
Wide input voltage range: 8V to 30V
Up to 1A output current
Single pin on/off and brightness control using DC voltage or PWM
Typical 5% output current accuracy
Inherent open-circuit LED protection
High efficiency (up to 95%)
High-Side Current Sense
Soft-start
Available in SOT89-5 packages
Applications
Low voltage halogen replacement LEDs
Automotive lighting
Low voltage industrial lighting
LED back-up lighting
Illuminated signs
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