MAX16808 Datasheet, PDF (1/21 Pages) Maxim Integrated Products – Integrated 8-Channel LED Drivers with Switch-Mode Boost and SEPIC Controller

19-0655; Rev 0; 10/06
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
♦ Eight Constant-Current Output Channels (Up to
55mA Each)
♦ ±3% Current Matching Among Outputs
♦ Paralleling Channels Allows Higher Current per
LED String
♦ Outputs Rated for 36V Continuous Voltage
♦ Output-Enable Pin for PWM Dimming (Up to 30kHz)
♦ One Resistor Sets LED Current for All Channels
♦ Wide Dimming Ratio Up to 5000:1
♦ Low Current-Sense Reference (300mV) for High
Efficiency
♦ 8V to 26.5V Input Voltage or Higher with External
Biasing Devices
♦ Open LED Detection (MAX16808)
♦ 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 lead-free package.
*Future product—contact factory for availability.
**EP = Exposed paddle.
Typical Operating Circuits
VIN
3V TO 5 5V
CN
CBYP
RSET
L
D
Q
COUT
CC2
RCS
CC1
RC1
OUT CS AGND
VCC
COMP
FB
V+
PGND
LE
DN
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
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