2. Application based on PWM dimming

LED1

LED2

LEDn

HM1810

12

3

GND

NC

OUT

DC POWERINPUT

R1

Q1

MOSFETN

Figure 3

As shown in Figure 3, PWM signal controls the conduction and cutting off of

HM1810 via the switch

circuit; when chip works in periodic on-off state, withstand voltage at OUT pin of

HM1810 can achieve 24V,

that is to say, when PWM signal is turned off, voltage at OUT pin of

HM1810 can be DC24.0V; while

conduction duty cycle shouldn’t be too high; and specific application reference is as follows:

HM1810-2：turn-on time duty cycle is less than 50%;

HM1810-3：turn-on time duty cycle is less than 30%.

If the remaining voltage that power voltage deducts overall voltage drop of serial LED lamp is higher,

divider resistance R1 should be serially connected to circuit so as to share voltage and power according to

Figure 3.

3. Notes of PCB design

In order to reduce working temperature of

HM1810 area of PCB copper foil connected with HM1810 pin

should be enlarged go the greatest extent so as to achieve better and quick radiating effect. Please refer to the

figure below.

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4 -

Single-channel LED Constant Current Driver Chip HM1810

Shenzhen H&M Semiconductor Co.Ltd

http：//www.hmsemi.com