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MAX16822A/MAX16822B
2MHz, High-Brightness LED
Drivers with Integrated MOSFET
and High-Side Current Sense
Typical Operating Characteristics (continued)
(V
IN
= V
DIM
= 48V, C
VCC
= 1µF, R
SENSE
= 0.62Ω, L = 220µH (connected between IN and CS). Typical values are at T
A
= +25°C,
unless otherwise noted.)
LX
RDSON
vs. TEMPERATURE
MAX16822A toc11
TEMPERATURE (°C)
LX
RDSON
(Ω)
1109580655035205-10-25
0.5
0.6
0.7
0.8
0.9
1.0
0.4
-40 125
V
IN
= 6.5V
V
IN
= 65V
V
IN
= 48V
I
TEMP_I
vs. TEMPERATURE
MAX16822A toc12
I
TEMP_I
(μA)
25.5
26.0
26.5
27.0
27.5
28.0
28.5
29.0
29.5
30.0
25.0
TEMPERATURE (°C)
1109580655035205-10-25-40 125
V
IN
= 48V
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.
