MAX16822A 데이터 시트보기 (PDF) - Maxim Integrated

부품명

상세내역

제조사

MAX16822A

2MHz, High-Brightness LED Drivers with Integrated MOSFET and High-Side Current Sense

Maxim Integrated 

MAX16822A/MAX16822B

2MHz, High-Brightness LED

Drivers with Integrated MOSFET

and High-Side Current Sense

HYSTERETIC

MODE

fSW

ILED

AVG. LED

CURRENT

ΔI

t

VDIM

t1

t2

t

Figure 2. Current-Regulator Operation

Freewheeling-Diode Selection

For stability and best efficiency, a low forward-voltage

drop diode with fast reverse-recovery time and low

capacitance is recommended. A Schottky diode is a

good choice as long as its breakdown voltage is high

enough to withstand the maximum operating voltage.

PCB Layout Guidelines

Careful PCB layout is critical to achieve low switching

losses and stable operation. Use a multilayer board

whenever possible for better noise immunity. Minimize

ground noise by connecting high-current ground

returns, the input bypass-capacitor ground lead, and

the output-filter ground lead to a single point (star

ground configuration). In normal operation, there are two

power loops. One is formed when the internal MOSFET

is on and the high current flows through IN, RSENSE,

LED load, the inductor, the internal MOSFET, and GND.

The other loop is formed when the internal MOSFET is

off and the high-current circulates through RSENSE, LED

load, the inductor, and the freewheeling diode. Minimize

each loop area to reduce noise interaction.

Place RSENSE as close as possible to CS and IN. For

better noise immunity, a Kelvin connection between CS

and RSENSE is strongly recommended.

www.maximintegrated.com

Maxim Integrated | 8

Share Link: