MP24833 – 3A, 55V, PROGRAMABLE FREQUENCY WHITE LED DRIVER

NOTICE:

The information in this document is subject to change without notice. Users should warrant and guarantee that third

party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not

assume any legal responsibility for any said applications.

MP24833 Rev. 1.0

www.MonolithicPower.com

15

11/28/2009

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2013 MPS. All Rights Reserved.

The inductance is 75uH, select a 68uH inductor,

the current ripple of inductor is about 0.88A. The

peak current of inductor is:

L_peak

L_AVG

L

1

II

ΔI

2

=+

The peak current is about 2.5A. Select an

inductor with saturation current around 3A.

Select Input and Output Capacitor

The input capacitor reduces the surge current

drawn from the input supply and the switching

noise from the device. Select a capacitance that

can limit the input voltage ripple

normally less than 5% to 10% of the DC value.

LED

OUT

IN

sIN

IN

OUT

IV

C

fV

(V

V

)

⋅

>

⋅Δ

⋅

+

The output capacitor keeps the output voltage

ripple

of the DC value) and ensures feedback loop

stability.

LED

OUT

OUT

sOUT

IN

OUT

IV

C

fV

(V

V

)

⋅

>

⋅Δ

⋅

+

Use two 2.2uF/50V X7R ceramic capacitors in

parallel as the input capacitor, and use a

4.7uF/50V X7R ceramic capacitor as the output

capacitor.

Select Rectifier Diode

Use a Schottky diode as the rectifier diode.

Select a diode that can withstand voltage stress

higher than 48V, and the current limit higher than

the output current. Use B360 in this application.

Setting Open Voltage Protection

Set the OVP point 20% higher than maximum

output voltage by voltage divider.

OVP1

OVP2

OVP

OVP2

RR

V1.2V

R

+

=×

The OVP setting resistor is R9=10kΩ and

R8=226kΩ

PCB LAYOUT

Layout is based on EV24833-N-00A

Figure 7—Top Layer

Figure 8—Bottom Layer