MAX16822A_10 Datasheet, PDF (1/10 Pages) Maxim Integrated Products – 2MHz, High-Brightness LED Drivers with Integrated MOSFET and High-Side Current Sense

19-4141; Rev 3; 1/10
EVAALVUAAILTAIOBNLEKIT
2MHz, High-Brightness LED Drivers with
Integrated MOSFET and High-Side Current Sense
General Description
The MAX16822A/MAX16822B step-down constant-cur-
rent high-brightness LED (HB LED) drivers provide a
cost-effective design solution for automotive
interior/exterior lighting, architectural and ambient light-
ing, LED bulbs, and other LED illumination applications.
The MAX16822A/MAX16822B operate from a +6.5V to
+65V input-voltage range and can provide an output
current up to 350mA, if operated up to a temperature of
+125°C, or up to 500mA, if operated up to a tempera-
ture of +105°C. A high-side current-sense resistor
adjusts the output current and a dedicated pulse-width
modulation (PWM) input enables pulsed LED dimming
over a wide range of brightness levels.
These devices are well suited for applications requiring
a wide input-voltage range. The high-side current sens-
ing and an integrated current-setting circuitry minimize
the number of external components while delivering an
average output current with ±3% accuracy. A hysteretic
control method ensures excellent input supply rejection
and fast response during load transients and PWM dim-
ming. The MAX16822A allows 10% current ripple and
the MAX16822B allows 30% current ripple. Both
devices operate up to a switching frequency of 2MHz,
thus allowing the use of small-sized components.
The MAX16822A/MAX16822B offer an analog dimming
feature that reduces the output current by applying an
external DC voltage below the internal 2V threshold volt-
age from TEMP_I to GND. TEMP_I also sources 25µA to
a negative temperature coefficient (NTC) thermistor con-
nected between TEMP_I and GND, thus providing an
analog thermal-foldback feature that reduces the LED
current when the temperature of the LED string exceeds
a specified temperature point.
An additional feature includes thermal-shutdown pro-
tection that turns off the LX driver when the junction
temperature exceeds +165°C.
The MAX16822A/MAX16822B operate over the -40°C to
+125°C automotive temperature range and are available
in an 8-pin SO package.
Applications
Architectural, Industrial, and Ambient Lighting
Automotive RCL, DRL, and Fog Lights
Heads-Up Displays
Indicator and Emergency Lighting
Pin Configuration appears at end of data sheet.
Features
o High-Efficiency Solution
o 6.5V to 65V Input-Voltage Range
o Output Current Up to 500mA
o On-Board 65V, 0.85Ω Power MOSFET
o Hysteretic Control: Up to 2MHz Switching
Frequency
o ±3% LED Current Accuracy
o 200mV Current-Sense Reference
o Resistor-Programmable Constant LED Current
o Integrated High-Side Current Sense
o Thermal-Foldback Protection/Linear Dimming
o Thermal-Shutdown Protection
o Available in an 8-Pin SO Package
o -40°C to +125°C Operating Temperature Range
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
MAX16822AASA+
-40°C to +125°C 8 SO
MAX16822AASA/V+ -40°C to +125°C 8 SO
MAX16822BASA+
-40°C to +125°C 8 SO
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
Typical Application Circuit
D1
HB LEDs
VIN
RSENSE
L1
C2
1 _CS
TEMP_I ⁸
NTC*
ON
2 _IN
DIM ⁷
OFF
MAX16822A
C1
3 _GND ^MAX16822B _LX 6
4 _PGND
LX ⁵
*OPTIONAL
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.