Hardware; Power Supply; Led Drivers; Figure 1: Ev-K0-Hcd Board (Top View) - NEC 78K0 User Manual

78K0 - Shine It!

2. Hardware

The EV-K0-HCD board measures 3.15 × 3.15 inches or 80 × 80 millimeters (mm). This small form factor
is enabled by the use of components such as inductors that are small in size thanks to the µPD78F8024
MCU's constant-current drives with high switching frequency.
The board is designed with four layers. The top layer contains most of the components, the first middle
layer serves as the power plane, the second middle layer adds additional space for traces, and the
bottom layer serves as the ground plane and assembly for the temperature sensor and high-power LEDs.
The heat generated by the LEDs is dissipated through the pads and vias surrounding the LEDs, and LED
temperature is sensed by the temperature sensor mounted on top of the dissipation pad.

Figure 1: EV-K0-HCD Board (Top View)

Figure 2: EV-K0-HCD Board (Bottom View)

2.1 Power Supply

The EV-K0-HCD board requires a 10 to 24 V power supply with output wattage of at least 5 watts (W)
DC
to light the high-power LEDs. The barrel-type power jack mounted on the board accepts a 2.1 mm center
pole connector (center positive).

2.2 LED Drivers

The board's four-channel LED drivers are set in buck topology for 350 milliamps (mA) of constant output
current. However, you can increase output current up to 700 mA by changing the current sensor's
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