2MHz, High-Brightness LED Drivers with

Integrated MOSFET and High-Side Current Sense

_______________________________________________________________________________________

5

Typical Operating Characteristics (continued)

unless otherwise noted.)

vs. TEMPERATURE

TEMPERATURE (

°C)

110

95

80

65

50

35

20

5

-10

-25

0.5

0.6

0.7

0.8

0.9

1.0

0.4

-40

125

vs. TEMPERATURE

25.5

26.0

26.5

27.0

27.5

28.0

28.5

29.0

29.5

30.0

25.0

TEMPERATURE (

°C)

110

95

80

65

50

35

20

5

-10

-25

-40

125

Pin Description

PIN

NAME

FUNCTION

1

CS

Current-Sense Input. Connect a resistor between IN and CS to program the LED current.

2

IN

Positive Supply Voltage Input. Bypass with a 1μF or higher value capacitor to GND.

3

GND

Ground

4

PGND

Power Ground

5, 6

LX

Switching Node

7

DIM

Logic-Level Dimming Input. Drive DIM low to turn off the current regulator. Drive DIM high to

enable the current regulator.

8

TEMP_I

Thermal Foldback Control and Linear Input. Bypass with a 0.01μF capacitor to GND if thermal

foldback or analog dimming is used. See the Thermal Foldback section for more details.

Detailed Description

The MAX16822A/MAX16822B are step-down, constant-

current, high-brightness LED (HB LED) drivers. These

devices operate from a +6.5V to +65V input-voltage

range. The maximum output current is 500mA, if the

part is used at temperatures up to +105°C, or 350mA, if

it is used up to +125°C. A high-side current-sense

resistor sets the output current and a dedicated PWM

dimming input enables pulsed LED dimming over a

wide range of brightness levels.

A high-side current-sensing scheme and an on-board

current-setting circuitry minimize the number of exter-

nal components while delivering LED current with ±3%

accuracy, using a 1% sense resistor. See Figure 1 for

an internal block diagram.