参数资料
型号: MIC2299-15YML TR
厂商: Micrel Inc
文件页数: 9/14页
文件大小: 0K
描述: IC LED DRIVR WHITE BCKLGT 12-MLF
标准包装: 1
恒定电流:
拓扑: PWM,升压(升压)
输出数: 1
内部驱动器:
类型 - 主要: 背光,闪灯/白光
类型 - 次要: 白色 LED
频率: 1.75MHz ~ 2.3MHz
电源电压: 2.5 V ~ 10 V
输出电压: 30V
安装类型: 表面贴装
封装/外壳: 12-VFDFN 裸露焊盘,12-MLF?
供应商设备封装: 12-MLF?(4x4)
包装: 标准包装
工作温度: -40°C ~ 125°C
产品目录页面: 1082 (CN2011-ZH PDF)
其它名称: 576-3052-6
Micrel, Inc.
Over-Voltage Protection
The MIC2299 offers over-voltage protection functionality.
If an LED is disconnected from the circuit or the
feedback pin is shorted to ground, the feedback pin will
fall to ground potential. This will cause the MIC2299 to
switch at full duty cycle in an attempt to maintain the
feedback voltage. As a result, the output voltage will
climb out of control. This may cause the switch node
voltage to exceed its maximum voltage rating, possibly
damaging the IC and the external components. To
ensure the highest level of protection, the MIC2299 OVP
pin will shut the switch off when an over-voltage
condition is detected, saving itself and the output
capacitor from damage. OVP threshold can be increase
by adding a resistor divider between the output and
ground. Be careful not to exceed the 30V rating of the
switch.
Figure 4. Adjustable OVP circuit
Brightness Control
Pin Brightness Functionality
MIC2299
Hence, a 200m ? sense resistor will achieve nominally
1A when both DIM and BRT pins are left open.
PWM control of brightness
A control signal can be driven into the enable pin to vary
average current through the LED for applications not
sensitive to low frequency (~100Hz) light modulation.
For such applications, the SS/DIM pin capacitance
should be minimized to achieve a fast turn on time. An
absent capacitor at the SS pin will achieve a soft start
period of approximately 1ms with a C COMP value of 33nF.
For other applications, where no analog control voltage
is available, the BRT pin can be driven through a low
pass filter (18k ? and 470nF) at a PWM frequency of
>5kHz to set the FB voltage, and therefore, the LED
current from 20% to 100% of Nominal LED current
(Figure 5).
Figure 5. High Frequency PWM Programming
Via BRT Pin
Since the DIM pin is typically utilized for soft start, it is
recommended to use the enable and BRT pins for the
PWM method of adjusting the average LED current.
BRT Pin
OPEN
GND
≥ 20k ? to 100k ?
[R BRT ] to GND
SS/DIM
OPEN
V SS/DIM
V FB (V)
200mV or V SS/DIM
40mV
(10μA × R BRT )/5
V FB (V)
200mV
V SS/DIM
Figures 6 and 7 below show typical results for this
method.
Table 1. BRT and SS/DIM Brightness Control Functionality
The MIC2299 has built in brightness/dimming
functionally for white LED applications. The BRT and
SS/DIM pins are available for brightness/dimming control
functionality. The table in Table 1 illustrates the different
modes of dimming offered by the BRT and SS/DIM pins.
The resulting LED current is then calculated as:
I LED = V FB /R SENSE
Figure 6. Enable Pin PWM Freq = 100Hz
Enable Pin Programming
October 2007
9
M9999-101907-B
相关PDF资料
PDF描述
MIC26603YJL EV BOARD EVAL FOR MIC26603YJL
MIC26901YJL EV BOARD EVAL FOR MIC26901YJL
MIC2841AYMT TR IC LED DRIVR WHITE BCKLGT 10TMLF
MIC2842AYMT TR IC LED DRIVR WHITE BCKLGT 10TMLF
MIC2843YMT TR IC LED DRIVER PWM CONTROL 10TMLF
相关代理商/技术参数
参数描述
MIC23030-4YMT TR 功能描述:直流/直流开关调节器 8MHz 400mA Hyper Light Load Buck Regulator RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MIC23030-4YMT-TR 功能描述:Buck Switching Regulator IC Positive Fixed 1.2V 1 Output 400mA 6-UFDFN Exposed Pad, 6-TMLF? 制造商:microchip technology 系列:HyperLight Load? 包装:剪切带(CT) 零件状态:停产 功能:降压 输出配置:正 拓扑:降压 输出类型:固定 输出数:1 电压 - 输入(最小值):2.7V 电压 - 输入(最大值):5.5V 电压 - 输出(最小值/固定):1.2V 电压 - 输出(最大值):- 电流 - 输出:400mA 频率 - 开关:8MHz 同步整流器:是 工作温度:-40°C ~ 125°C (TJ) 安装类型:表面贴装 封装/外壳:6-UFDFN 裸露焊盘,6-TMLF? 供应商器件封装:6-TMLF?(1.6x1.6) 标准包装:1
MIC23030-AYMT TR 功能描述:直流/直流开关调节器 8MHz 400mA Hyper Light Load Buck Regulator RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5
MIC23030-AYMT-TR 功能描述:Buck Switching Regulator IC Positive Adjustable 0.7V 1 Output 400mA 6-UFDFN Exposed Pad, 6-TMLF? 制造商:microchip technology 系列:HyperLight Load? 包装:剪切带(CT) 零件状态:停产 功能:降压 输出配置:正 拓扑:降压 输出类型:可调式 输出数:1 电压 - 输入(最小值):2.7V 电压 - 输入(最大值):5.5V 电压 - 输出(最小值/固定):0.7V 电压 - 输出(最大值):3.6V 电流 - 输出:400mA 频率 - 开关:8MHz 同步整流器:是 工作温度:-40°C ~ 125°C (TJ) 安装类型:表面贴装 封装/外壳:6-UFDFN 裸露焊盘,6-TMLF? 供应商器件封装:6-TMLF?(1.6x1.6) 标准包装:1
MIC23030-CYMT TR 功能描述:直流/直流开关调节器 8MHz 400mA Hyper Light Load Buck Regulator RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5