1.2A LED driver with internal switch
The CL6808 is a continuous mode inductive step-down converter, designed for driving single
or multiple series connected LE Ds efficiently from a voltage s ource higher than the LED voltage.
The device operates from an i nput supply betw een 7V an d 40V and p rovides an extern ally
adjustable output current of up to 1.2 A. Depending upon supply voltage and external components,
this can provide up to 35 watts of output power.
The CL6808 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.
◆ Simple low parts count
◆ Wide input voltage range: 8V to 40V
◆ Up to 1.2A 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
◆ Available in SOT89-5 packages
◆ Low voltage halogen replacement LEDs
◆ Automotive lighting
◆ Low voltage industrial lighting
◆ LED back-up lighting
◆ Illuminated signs