EV-184

AHK1421 EVAL :

EVALUATION BOARD DATASHEET

EV-184.2011.05.1.0

3

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Getting Started

Setup (Figure 3)

1. Connect an input power source (to supply between 2.7V and 5.5V) to the board by placing the jumper, J1 on the

left (Connects DC+ power to AHK1421).

2. Connect the DC+ power to the microcontroller VDD by using the jumper V_MCU.

3. Connect the EN/SET jumper to connect the microcontroller GPIOs to the AHK1421 EN/SET pins.

4. After all jumpers are in the correct position, apply power between 2.7V and 5.5V to the DC+ and DC- terminals to

power on the AHK1421 (U1) and microcontroller (U2). The red LED (LED1) will illuminate when the microcontroller

is powered. The green LED (LED2) will flicker when the three buttons to transfer S²C wire data for AHK1421 are

operated.

5. Use the UP, DOWN and CYCLE buttons to vary the brightness of the 6 white LEDs using the EN/SET serial data

Figure 3: AHK1421 Evaluation Board Measurement Configuration

buttons. The AHK1421 records the number of rising edges which control output current in EN/SET pin and change the

value of output current from 20mA to 0.4mA when RFB is 12.5Ω

• UP button: The UP button increments the number of EN/SET rise edges from 1 to 32 each time this button is pushed.

By holding down the button for more than 0.6 seconds, the microcontroller enters auto-increment mode. The LED

• DOWN button: The DOWN button decrements the number of EN/SET rise edges from 32 to 1 each time this button

is pushed. By holding down the button for more than 0.6 seconds, the microcontroller enters auto-decrement mode.

• CYCLE button: The button increments or decrements the number of EN/SET edges automatically and cyclically after

a single push according to the previous EN edges up or down event.

• UP+DOWN+CYCLE button: EN/SET is set to 0V and the AHK1421 is shut down. All white LEDs are turned off.