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参数资料
| 型号： | MAX16834ATP+ |
| 厂商： | Maxim Integrated |
| 文件页数： | 10/23页 |
| 文件大小： | 0K |
| 描述： | IC LED DRIVR HIGH BRIGHT 20-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 特色产品： | MAX16834 High-Power LED Driver |
| 标准包装： | 75 |
| 拓扑： | PWM，SEPIC，降压（降压），升压（升压） |
| 输出数： | 1 |
| 内部驱动器： | 无 |
| 类型 - 主要： | 车载，背光 |
| 类型 - 次要： | 高亮度 LED（HBLED），RGB |
| 频率： | 100kHz ~ 1MHz |
| 电源电压： | 4.75 V ~ 28 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 20-WFQFN 裸露焊盘 |
| 供应商设备封装： | 20-TQFN-EP |
| 包装： | 管件 |
| 工作温度： | -40°C ~ 125°C |
MAX16834
High-Power LED Driver with Integrated High-Side LED
Current Sense and PWM Dimming MOSFET Driver
Internal Transconductance Error Amplifier
The MAX16834 has a built-in transconductance amplifi-
er used to amplify the error signal inside the feedback
loop. The amplified current-sense signal is connected
to the negative input of the g m amplifier with the current
reference connected to REFI. The output of the op amp
is controlled by the input at PWMDIM. When the signal
at PWMDIM is high, the output of the op amp connects
to COMP; when the signal at PWMDIM is low, the out-
put of the op amp disconnects from COMP to preserve
the charge on the compensation capacitor. When the
voltage at PWMDIM goes high, the voltage on the com-
pensation capacitor forces the converter into a steady
state. COMP is connected to the negative input of the
PWM comparator with CMOS inputs, which draw very
little current from the compensation capacitor at COMP
and thus prevent discharge of the compensation
capacitor when the PWMDIM input is low.
Internal Oscillator
The internal oscillator of the MAX16834 is programma-
ble from 100kHz to 1MHz using a single resistor at
RT/SYNC. Use the following formula to calculate the
switching frequency:
grammed by the external capacitor connected at SC.
The current source charging the capacitor is 100μA.
Overvoltage Protection (OVP+)
OVP+ sets the overvoltage threshold limit across the
LEDs. Use a resistive divider between output OVP+
and LV to set the overvoltage threshold limit. An internal
overvoltage protection comparator senses the differen-
tial voltage across OVP+ and LV. If the differential volt-
age is greater than 1.435V, NDRV is disabled and FLT
asserts. When the differential voltage drops by 200mV,
NDRV is enabled and FLT deasserts. The PWM dim-
ming MOSFET is still controlled by the PWMDIM input.
Fault Indicator ( FLT )
The MAX16834 features an active-low, open-drain fault
indicator ( FLT ). FLT asserts when one of the following
occurs:
1) Overvoltage across the LED string
2) Short-circuit condition across the LED string, or
3) Overtemperature condition
When the output voltage drops below the overvoltage
set point minus the hysteresis, FLT deasserts. Similarly
during the short-circuit period, the fault signal
f OSC (kHz) =
5000k ?
RT(k ? )
× (kHz)
deasserts when the dimming MOSFET is on, which
happens every hiccup cycle during short circuit. During
overtemperature fault, the FLT signal is the inverse of
where RT is the resistor from RT/SYNC to SGND.
The MAX16834 synchronizes to an external clock signal
at RT/SYNC. The application of an external clock dis-
ables the internal oscillator allowing the MAX16834 to
use the external clock for switching operation. The
internal oscillator is enabled if the external clock is
absent for more than 50μs. The synchronizing pulse
minimum width for proper synchronization is 200ns.
Switching MOSFET
Current-Sense Input (CS)
CS is part of the current-mode control loop. The switch-
ing control uses the voltage on CS, set by R CS , to termi-
nate the on pulse width of the switching cycle, thus
achieving peak current-mode control. Internal leading-
edge blanking is provided to prevent premature turn-off
of the switching MOSFET in each switching cycle.
Slope Compensation (SC)
The MAX16834 uses an internal-ramp generator for
slope compensation. The ramp signal also resets at the
beginning of each cycle and slews at the rate pro-
10
the PWM input.
Applications Information
Setting the UVLO Threshold
The UVLO threshold is set by resistors R1 and R2 (see
Figure 2). The MAX16834 turns on when the voltage
across R2 exceeds 1.435V, the UVLO threshold. Use
the following equation to set the desired UVLO thresh-
old:
V UVEN = 1 . 435 V ( R 1 + R 2 ) R 2
In a typical application, use a 10k ? resistor for R2 and
then calculate R1 based on the desired UVLO threshold.
Setting the Overvoltage Threshold
The overvoltage threshold is set by resistors R4 and R9
(see Figure 2). The overvoltage circuit in the MAX16834
is activated when the voltage on OVP+ with respect to
LV exceeds 1.435V. Use the following equation to set
the desired overvoltage threshold:
V OV = 1 . 435 V ( R 4 + R 9 ) R 9
Maxim Integrated
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX16834ATP/V+ | 功能描述:LED照明驱动器 w/Int Hside Crnt Sns & PWM Dim MOSFET 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 |
| MAX16834ATP/V+CEU | 制造商:Maxim Integrated Products 功能描述:HIGH-POWER LED DRIVER WITH INTEGRATED HIGH-SIDE LED CURRENT - Rail/Tube |
| MAX16834ATP/V+T | 功能描述:LED照明驱动器 w/Int Hside Crnt Sns & PWM Dim MOSFET 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 |
| MAX16834ATP/V+TCEU | 制造商:Maxim Integrated Products 功能描述:HIGH-POWER LED DRIVER WITH INTEGRATED HIGH-SIDE LED CURRENT - Tape and Reel |
| MAX16834ATP+ | 功能描述:LED照明驱动器 w/Int Hside Crnt Sns & PWM Dim MOSFET 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 |
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