MAX16805_07 Datasheet, PDF (1/19 Pages) Maxim Integrated Products – EEPROM-Programmable, High-Voltage, 350mA LED Drivers with LED Current Foldback

19-0625; Rev 1; 1/07
EVAALVUAAILTAIOBNLEKIT
EEPROM-Programmable, High-Voltage,
350mA LED Drivers with LED Current Foldback
General Description
The MAX16805/MAX16806 LED drivers eliminate the
need for microcontrollers or switch-mode converters for
automotive interior dome, map, and courtesy light
applications. An EEPROM-programmable LED current-
sense reference simplifies production by using one
sense resistor to set the LED current for all LED bins. A
dual-mode DIM pin and an on-board 200Hz ramp gen-
erator allow for PWM dimming with an analog or PWM
control signal. The analog control signal at dimming
input DIM allows for the “theater dimming” effect to be
implemented. Fast turn-on/-off times ensure a wide-
range PWM operation, while waveshaping circuitry min-
imizes EMI. EEPROM-programmable LED current
foldback makes it possible to operate at a high input
voltage, while saving the cost and space associated
with having a large heatsink. The MAX16806 works with
an external thermal sensor to maintain maximum LED
junction temperature by folding back the LED current.
The thermal foldback temperature knee and slope are
EEPROM programmable. The MAX16806 SW pin sup-
plies necessary wetting current to a momentary switch.
Applications
Automotive Interior: Map, Dome, and Courtesy
Lighting
Automotive Exterior:
Rear Combination Light (RCL)
Daytime Running Light (DRL)
Adaptive Front Light
Emergency Vehicle Warning Lights
Navigation and Marine Indicators
Features
♦ EEPROM or I²C Dynamically Programmable:
LED Current Foldback for High Input Voltage
LED Current Reference
LED Current Thermal Foldback (MAX16806)
♦ On-Board 200Hz Ramp Generator Eliminates the
Need for µC PWM Signal
♦ Flexible Analog or PWM Control for PWM or
Theater Dimming
♦ Wetting Current and Debounce for Momentary
Switch (MAX16806)
♦ 5.5V to 40V Input with Up to 39V Output Capability
♦ 35mA to 350mA Adjustable LED Current
♦ Waveshaping Minimizes EMI During Dimming
♦ Output Short-Circuit and Overtemperature
Protection
♦ -40°C to +125°C Operating Temperature Range
Ordering Information
PART
TEMP RANGE
PIN
PACKAGE
PKG
CODE
MAX16805ATP+ -40°C to +125°C 20 TQFN-EP** T2055M-5
MAX16806ATP+ -40°C to +125°C 20 TQFN-EP** T2055M-5
+Denotes lead-free package.
**EP = Exposed pad.
Pin Configurations appear at end of data sheet.
Typical Operating Circuits
+5.5V TO +40V
IN
0.1μF
EN
SERIAL CLOCK
SCL
SERIAL DATA
SDA
V5
MAX16805
I_LED
OUT
+5V REG
V5
0.1μF
CS+
LEDs
RSENSE
CS-
DIM
GND
+5.5V TO +40V
IN
V5
0.1μF
EN
V_CC
MAX6613^† OUT
MAX16806
TFP/SCL
I_LED
OUT
+5V REG
V5
0.1μF
CS+
TFN/SDA
GND
CS-
SW
PWM DIMMING
DIM
GND
LEDs
RSENSE
ANALOG CONTROL PWM DIMMING
†_{MAX6613 THERMAL SENSOR IS OPTIONAL.}
PWM CONTROL DIMMING
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.