MP2410A

– 24V, 2A, 1MHZ, SYNCHRONOUS, STEP-DOWN, LED DRIVER

MP2410A Rev. 1.0

www.MonolithicPower.com

14

4/25/2016

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

© 2016 MPS. All Rights Reserved.

APPLICATION INFORMATION

Setting the LED Current

A current sense resistor is inserted between the

anode of LED and GND. The current sense

resistor value can be calculated with Equation

(1):

S

LED

0.1V

R

I



(1)

Selecting the Inductor

An inductor less than 100µH with a nominal DC

current rating at least 25% higher than the

maximum load current is recommended for most

applications. For the highest efficiency, the

inductor’s DC resistance should be less than

1

00mΩ.

For

most

designs,

the

required

inductance value can be derived from Equation

(2):

OUT

IN

OUT

IN

L

SW

V

(V

V

)

L

V

I

f





  

(2)

Where

∆I

Choose the inductor ripple current to be 30% of

the

maximum

load

current.

The

maximum

inductor peak current can be calculated with

Equation (3):

L

L(MAX)

LED

I

II

2





(3)

Selecting the Input Capacitor

The input capacitor reduces the surge current

drawn from the input supply and the switching

noise from the device. The input capacitor

impedance at the switching frequency should be

less than the source impedance to prevent the

high-frequency switching current from passing

through the input. Ceramic capacitors with X5R

or X7R dielectrics are highly recommended

because of their low ESR and small temperature

coefficients. For most applications, a 10µF

capacitor is sufficient.

Selecting the Output Capacitor

The output capacitor keeps the output current

ripple small and ensures feedback loop stability.

The output capacitor impedance should be low at

the switching frequency. Ceramic capacitors with

X5R or X7R dielectrics are recommended for

their

low

ESR

characteristics.

For

most

applications,

a

10µF

ceramic

capacitor

is

sufficient.

PCB Layout Guidelines

Efficient

PCB

layout

is

critical

for

stable

operation. For best results, refer to the guidelines

below.

SW) very close to the device with short,

direct, and wide traces.

2. Place the input capacitor as close to IN and

GND as possible.

3. Place the external feedback resistors next to

FB.

4. Keep the switch node traces short and away

from the feedback network.

For more information, please refer to the related

evaluation board datasheet.