參數資料
型號: MP1518DJE
廠商: MONOLITHIC POWER SYSTEMS INC
元件分類: 顯示驅動器
英文描述: Fixed Frequency White LED Driver
中文描述: LED DISPLAY DRIVER, PDSO6
封裝: MO-193AB, TSOT-23, 6 PIN
文件頁數: 7/9頁
文件大?。?/td> 260K
代理商: MP1518DJE
MP1518 – FIXED FREQUENCY WHITE LED DRIVER
MP1518 Rev. 1.6
7/25/2006
www.MonolithicPower.com
7
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
2006 MPS. All Rights Reserved.
TM
Other applications need to use a logic signal to
do the dimming. This can be seen in Figure 7.
The PWM signal is applied to the EN pin of the
MP1518. The LEDs will switch between full load
to completely shut off. The average current
through the LEDs will increase proportionally to
the duty cycle of the PWM signal. The PWM
signal used in Figure 7 should be 1KHz or
below due to the soft-start function.
PWM
MP1518
LED1
LED2
LED3
FB
EN
Figure 7—PWM Dimming Control Using a
Logic Signal
If the PWM signal is above 1KHz, dimming can
be achieved by using the circuit shown in
Figure 8.
PWM
MP1518
LED1
LED2
LED3
FB
Figure 8— Dimming Control Using a Filtered
PWM Signal
Open Load Protection
Open Load protection will shut off the MP1518
if the output voltage goes too high when the OV
pin is tied to the output. In some cases an LED
may fail, this will result in the feedback voltage
always being zero.
The part will run at maximum duty cycle
boosting the output voltage higher and higher.
By tying the OV pin to the top of the LED string
the MP1518 checks this condition and if the
output ever exceeds 28V the MP1518 will shut
down. The part will not switch again until the
power is recycled. Figure 9 shows the behavior
of the MP1518 into an open load.
V
EN
5V/div.
V
10V/div.
V
10V/div.
Startup Waveforms into
an Open Load
V
IN
= 3.6V
Figure 9—Startup Waveforms into an Open
Load
Layout Considerations
Careful attention must be paid to the PCB
board layout and component placement. Proper
layout of the high frequency switching path is
critical to prevent noise and electromagnetic
interference problems. Due to the high
frequency switching the length and area of all
the traces connected to the switch node should
be minimized. Refer to the evaluation board
EV0056 for a sample layout of the MP1518.
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相關代理商/技術參數
參數描述
MP1518DJE-LF-P 制造商:Monolithic Power Systems 功能描述:6 LED, 2.6-6VIN SWITCH DRIVER, BETTER EMI VERSION OF MP1518D - Tape and Reel 制造商:Monolithic Power Systems 功能描述:6 LED, 2.6 - 6Vin Switch Driver
MP1518DJE-LF-Z 制造商:Monolithic Power Systems 功能描述:LED DRVR 6SEGMENT 2.5V TO 6V 6PIN TSOT-23 - Tape and Reel 制造商:Monolithic Power Systems 功能描述:LED DRVR 6SEGMENT 2.5V TO 6V 6PIN TSOT-23 - Cut TR (SOS) 制造商:Monolithic Power Systems 功能描述:6 LED, 2.6 - 6Vin Switch Driver
MP1518DJ-LF-P 功能描述:電源開關 IC - 配電 6 LED, 2.6 - 6Vin Switch Driver RoHS:否 制造商:Exar 輸出端數量:1 開啟電阻(最大值):85 mOhms 開啟時間(最大值):400 us 關閉時間(最大值):20 us 工作電源電壓:3.2 V to 6.5 V 電源電流(最大值): 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:SOT-23-5
MP1518DJ-LF-Z 功能描述:電源開關 IC - 配電 6 LED, 2.6 - 6Vin Switch Driver RoHS:否 制造商:Exar 輸出端數量:1 開啟電阻(最大值):85 mOhms 開啟時間(最大值):400 us 關閉時間(最大值):20 us 工作電源電壓:3.2 V to 6.5 V 電源電流(最大值): 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:SOT-23-5
MP1519 制造商:MPS 制造商全稱:Monolithic Power Systems 功能描述:1x, 1.5x, 2x High Efficiency Charge Pump 4 White LED Driver