High-Voltage, 350mA, High-Brightness LED
Driver with PWM Dimming and 5V Regulator
Functional Diagram
IN
V5
DIM
REGULATOR
IN
EN
ENABLE
REFERENCE
GENERATOR
I_ REG
OUT
MAX16803
THERMAL
SHUTDOWN
DIFFERENTIAL
SENSE
AMPLIFIER
CS+
CS-
Detailed Description
The MAX16803 is a high-current regulator capable of
providing up to a total of 350mA of current to one or
more strings of HB LEDs. A wide operating input volt-
age range of +6.5V to +40V makes the MAX16803
ideal for automotive applications. A +5V regulated out-
put provides up to 4mA of current to power external cir-
cuitry. In addition, the MAX16803 features thermal and
output short-circuit protection. The wide operating volt-
age range helps protect the MAX16803 against large
transients such as those found in load-dump situations
up to 40V.
The MAX16803 uses a feedback loop to control the out-
put current. The differential voltage across the sense
resistor is compared to a fixed reference voltage, and
the error is amplified to serve as the drive to the internal
power series pass device (see the Functional
Diagram). The regulation point is factory-set at (V CS+ -
V CS- ) = 203mV ±3.5%. The regulated current is user
defined by the value of R SENSE .
The MAX16803 is a current controller internally opti-
mized for driving the impedance range expected from
one or more HB LEDs.
+5V Regulator
The MAX16803 includes a fixed +5V output regulator
that delivers up to 4mA of load current throughout the
+6.5V to +40V input voltage range. Connect a 0.1μF
compensation capacitor from V5 to ground. Shorting
V5 to ground disables the thermal shutdown. When EN
is low, V5 is off. V5 stays on during PWM dimming.
Thermal Protection
The MAX16803 enters a thermal-shutdown mode in the
event of overheating. This typically occurs in overload or
output short-circuit conditions. If the junction tempera-
ture exceeds T J = +155°C (typ), the internal thermal-pro-
tection circuitry turns off the series pass device. The
MAX16803 recovers from thermal-shutdown mode once
the junction temperature drops by 23°C (typ). The part
therefore protects itself by thermally cycling in the event
of a short-circuit or overload condition.
Applications Information
Programming the LED Current
The MAX16803 uses a sense resistor across CS+ and
CS- to set the LED current. The differential sense ampli-
fier connected across R SENSE provides ground-loop
immunity and low-frequency noise rejection. The LED
current is given by
I LED = V SENSE / R SENSE
6
_______________________________________________________________________________________
相关PDF资料
MAX16806EVMAXQUSB+ EVAL KIT FOR MAX16806
MAX16807EVKIT+ EVAL KIT FOR MAX16807
MAX16809EVKIT+ EVAL KIT FOR MAX16809
MAX16814EVKIT+ KIT EAL FOR MAX16814
MAX16816EVKIT+ KIT EVAL FOR MAX16816 LED DRIVER
MAX16818EVKIT+ KIT EVALUATION FOR MAX16818
MAX16820EVKIT+ EVAL KIT FOR MAX16820
MAX16821BEVKIT+ KIT EVAL FOR MAX16821B
相关代理商/技术参数
MAX16803EVKIT+BJT 功能描述:LED 照明开发工具 RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装:
MAX16804ATP+ 功能描述:LED照明驱动器 350mA HB LED Drvr w/analog & PWM Dim RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
MAX16804ATP+T 功能描述:LED照明驱动器 350mA HB LED Drvr w/analog & PWM Dim RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
MAX16805ATP+ 功能描述:LED照明驱动器 EEPROM-Prog 350mA w/Current Foldback RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
MAX16805ATP+T 功能描述:LED照明驱动器 EEPROM-Prog 350mA w/Current Foldback RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
MAX16806ATP+ 功能描述:LED照明驱动器 EEPROM-Prog 350mA w/Current Foldback RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
MAX16806ATP+T 功能描述:LED照明驱动器 EEPROM-Prog 350mA w/Current Foldback RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N
MAX16806EVCMAXQU+ 功能描述:LED 照明开发工具 RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装: