MAX16807_07 Datasheet, PDF (1/21 Pages) Maxim Integrated Products – Integrated 8-Channel LED Drivers with Switch-Mode Boost and SEPIC Controller

19-0655; Rev 1; 4/07
EVAALVUAAILTAIOBNLEKIT
Integrated 8-Channel LED Drivers with
Switch-Mode Boost and SEPIC Controller
General Description
The MAX16807/MAX16808 are integrated, high-efficien-
cy white or RGB LED drivers. They are designed for
LCD backlighting and other LED lighting applications
with multiple strings of LEDs. The MAX16807/
MAX16808’s current-mode PWM controller regulates
the necessary voltage to the LED array. Depending on
the input voltage and LED voltage range, it can be
used with boost or buck-boost (SEPIC) topologies. The
MAX16807/MAX16808 feature an 8V to 26.5V input volt-
age range. A wide range of adjustable frequency
(20kHz to 1MHz) allows design optimization for efficien-
cy and minimum board space.
The MAX16807/MAX16808 LED drivers include eight
open-drain, constant-current-sinking LED driver outputs
rated for 36V continuous operation. The LED current-
control circuitry achieves ±3% current matching among
strings and enables paralleling of outputs for LED string
currents higher than 55mA. The output-enable pin is
used for simultaneous PWM dimming of all output chan-
nels. Dimming frequency range is 50Hz to 30kHz and
dimming ratio is up to 5000:1. The constant-current out-
puts are single resistor programmable and the LED cur-
rent can be adjusted up to 55mA per output channel.
The MAX16807/MAX16808 operate either in stand-alone
mode or with a microcontroller (µC) using an industry-
standard, 4-wire serial interface. The MAX16808 includes
circuitry that automatically detects open-circuit LEDs.
The MAX16807/MAX16808 include overtemperature
protection, operate over the full -40°C to +125°C tem-
perature range, and are available in a thermally
enhanced, 28-pin TSSOP exposed paddle package.
Pin Configurations appear at end of data sheet.
Features
o Eight Constant-Current Output Channels (Up to
55mA Each)
o ±3% Current Matching Among Outputs
o Paralleling Channels Allows Higher Current per
LED String
o Outputs Rated for 36V Continuous Voltage
o Output-Enable Pin for PWM Dimming (Up to 30kHz)
o One Resistor Sets LED Current for All Channels
o Wide Dimming Ratio Up to 5000:1
o Low Current-Sense Reference (300mV) for High
Efficiency
o 8V to 26.5V Input Voltage or Higher with External
Biasing Devices
o Open LED Detection (MAX16808)
o 4-Wire Serial Interface to Control Individual
Output Channels
Applications
LCD White or RGB LED Backlighting:
LCD TVs, Desktop, and Notebook Panels
Automotive Navigation, Heads-Up,
and Infotainment Displays
Industrial and Medical Displays
Ambient, Mood, and Accent Lighting
Ordering Information
PART
T EM P
RANGE
PIN-PACKAGE
PKG
CODE
MAX16807AUI+ -40°C to +125°C 28 TSSOP-EP* U28ME-1
MAX16808AUI+ -40°C to +125°C 28 TSSOP-EP* U28ME-1
+Denotes a lead-free package.
*EP = Exposed paddle.
Typical Operating Circuits
VIN
3V TO 5.5V
CIN
CBYP
RSET
L
D
Q
COUT
CC2
RCS
CC1
RC1
OUT CS AGND
VCC
COMP
FB
V+
PGND
LE
DIN
CLK
DOUT
OE
SET
REF
OUT0
OUT1
MAX16807
OUT2
MAX16808
OUT3
OUT4
OUT5
OUT6
OUT7
RTCT
RT
CREF
CT
VOUT
R1
LEDs
R2
STAND-ALONE OPERATION
Typical Operating Circuits continued at end of data sheet.
________________________________________________________________ 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.