MAX16801A Datasheet, PDF (1/15 Pages) Maxim Integrated Products – Off-Line and DC-DC PWM Controllers for High-Brightness LED Drivers

19-3880; Rev 0; 10/05
Off-Line and DC-DC PWM Controllers for
High-Brightness LED Drivers
General Description
The MAX16801A/B/MAX16802A/B high-brightness (HB)
LED driver-control ICs contain all the circuitry required
for the design of wide-input voltage range LED drivers
for general lighting and display applications. The
MAX16801 is well suited for universal input (rectified
85VAC to 265VAC) LED drivers, while the MAX16802 is
intended for low-input-voltage (10.8VDC to 24VDC) LED
drivers.
When the LED current needs to be tightly regulated, an
additional on-board error amplifier with 1% accurate ref-
erence can be utilized. A wide dimming range can be
implemented by using low-frequency PWM dimming.
The MAX16801/MAX16802 feature an input undervoltage
lockout (UVLO) for programming the input-supply start
voltage, and to ensure proper operation during brownout
conditions. The MAX16801 has an internal-bootstrap
undervoltage lockout circuit with a large hysteresis that
simplifies off-line LED driver designs. The MAX16802
does not have this internal bootstrap circuit and can be
biased directly from a +12V rail.
The 262kHz fixed switching frequency is internally
trimmed, allowing for optimization of the magnetic and fil-
ter components, resulting in a compact, cost-effective
LED driver.The MAX16801A/MAX16802A are offered with
50% maximum duty cycle. The MAX16801B/MAX16802B
are offered with 75% maximum duty cycle. These devices
are available in an 8-pin µMAX^® package and operate
over the -40°C to +85°C temperature range.
Applications
Off-Line and DC-DC
LED Drivers
Commercial and
Industrial Lighting
RGB Back Light for LCD
TVs and Monitors
Decorative and
Architectural Lighting
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Features
♦ Suitable for Buck, Boost, Flyback, SEPIC, and
Other Topologies
♦ Up to 50W or Higher Output Power
♦ Universal Off-Line Input Voltage Range: Rectified
85VAC to 265VAC (MAX16801)
♦ IN-Pin Directly Driven From 10.8VDC to 24VDC
Input (MAX16802)
♦ Internal Error Amplifier with 1% Accurate
Reference for Precise LED Current Regulation
♦ PWM or Linear Dimming
♦ Fixed Switching Frequency of 262kHz ±12%
♦ Thermal Shutdown
♦ Digital Soft-Start
♦ Programmable Input Startup Voltage
♦ Internal Bootstrap UVLO with Large Hysteresis
(MAX16801)
♦ 45µA (typ) Startup Supply Current, 1.4mA (typ)
Operating Supply Current
♦ 50% (MAX16801A/MAX16802A) or 75%
(MAX16801B/MAX16802B) Maximum Duty Cycle
♦ Available in a Tiny 8-Pin µMAX Package
Ordering Information
PART
TEMP
RANGE
PIN-
PACKAGE
MAX16801AEUA+
-40°C to +85°C
8 µMAX
MAX16801BEUA+
-40°C to +85°C
8 µMAX
MAX16802AEUA+* -40°C to +85°C
8 µMAX
MAX16802BEUA+
-40°C to +85°C
8 µMAX
+Denotes lead-free package.
*Future product–contact factory for availability.
Typical Operating Circuit
10.8VDC TO 24VDC
ENABLE
PWM
UVLO/EN
IN
DIM/FB
VCC
MAX16802B
COMP
CS
U1
NDRV
GND
L1
C3
LEDs
D1
Q1
C1
C2
R1
GND
Warning: The MAX16801/MAX16802 are designed to work with high voltages. Exercise caution.
________________________________________________________________ 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.