AL8808EV1

Issue 1 – January 2013

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© Diodes Incorporated 2013

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AL8808EV1 EVALUATION BOARD REFERENCE DESIGN

The AL8808EV1 is configured to the reference design shown in Figure 2.

The operating voltage is a nominal 30V. The nominal current is set at 680mA with a 0R15 sense

resistor R1. The circuit operates in continuous mode at approximately 188kHz, with a 68uH inductor

and one LED.

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Both DC and PWM dimming can be achieved by driving the CTRL pin. For DC dimming, the

CTRL pin may be driven between 0.5V and 2.5V adjusting the output current from 25% to

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Driving the CTRL pin below 0.4V will shut down the output current.

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A PWM signal (low level ≤ 0.4V and high level > 2.5) allows the output current to be adjusted

above or below the level set by the resistor connected to SET input pin. The PWM frequency

can be between 100Hz to 1kHz, providing a resolution of 10 bits.

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For low frequency PWM, C2 should be removed from the evaluation board, to give a more

accurate duty cycle.

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Shorting R2 will connect the test pin CTRL to device pin CTRL, if required.

For other reference designs or further applications information, please refer to the AL8808 datasheet.

Figure 2. Schematic diagram