- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄377657 > LQH2MCN100K02 (Linear Technology Corporation) 20mA LED Driver and OLED Driver with Integrated Schottky in 3mm x 2mm DFN PDF資料下載
參數(shù)資料
| 型號： | LQH2MCN100K02 |
| 廠商： | Linear Technology Corporation |
| 英文描述： | 20mA LED Driver and OLED Driver with Integrated Schottky in 3mm x 2mm DFN |
| 中文描述： | 20mA的LED驅(qū)動器和3毫米的OLED驅(qū)動器集成肖特基x 2mm DFN封裝 |
| 文件頁數(shù)： | 12/24頁 |
| 文件大?。?/td> | 449K |
| 代理商： | LQH2MCN100K02 |
LT3498
12
3498f
LED CURRENT (mA)
50
E
60
70
80
55
65
75
4
8
12
16
20
2
0
6
10
14
18
3498 F07
V
= 3.4V
4 LEDs
100Hz = PWM
Direct PWM Dimming
Changing the forward current flowing in the LEDs not only
changes the intensity of the LEDs, it also changes the color.
The chromaticity of the LEDs changes with the change in
forward current. Many applications cannot tolerate any
shift in the color of the LEDs. Controlling the intensity of
the LEDs with a direct PWM signal allows dimming of the
LEDs without changing the color. In addition, direct PWM
dimming offers a wider dimming range to the user.
Dimming the LEDs via a PWM signal essentially involves
turning the LEDs on and off at the PWM frequency. The
typical human eye has a limit of ~60 frames per second.
By increasing the PWM frequency to ~80Hz or higher,
the eye will interpret that the pulsed light source is con-
tinuously on. Additionally, by modulating the duty cycle
(amount of “on-time”), the intensity of the LEDs can be
controlled. The color of the LEDs remains unchanged in
this scheme since the LED current value is either zero or
a constant value.
Figure 5 shows a Li-Ion powered driver for four white
LEDs. Direct PWM dimming method requires an external
NMOS tied between the cathode of the lowest LED in the
string and ground as shown in Figure 5. A simple logic
level Si2304 MOSFET can be used since its source is
connected to ground. The PWM signal is applied to the
CTRL1 pin of the LT3498 and the gate of the MOSFET.
The PWM signal should traverse between 0V to 5V, to
ensure proper turn-on and -off of the driver and the NMOS
transistor Q1. When the PWM signal goes high, the LEDs
are connected to ground and a current of I
LED
= 200mV /
R
SENSE1
flows through the LEDs. When the PWM signal
goes low, the LEDs are disconnected and turn off. The
MOSFET ensures that the LEDs quickly turn off without
discharging the output capacitor which in turn allows the
LEDs to turn on faster. Figure 6 shows the PWM dimming
waveforms for the circuit in Figure 5.
APPLICATIONS INFORMATION—LED DRIVER
Figure 7. PWM Dimming Efficiency
Figure 5. Li-Ion to Four White LEDs
with Direct PWM Dimming
Figure 6. Direct PWM Dimming Waveforms
CAP1
S
W1
CAP2 V
OUT2
V
IN
LT349
8
GND1
GND2
S
W2
C
IN
1
μ
H
R
S
EN
S
E1
10
Q1
S
i2304BD
S
349
8
F05
C
OUT1
μ
F
V
IN
3V TO 5V
L1
15
μ
H
LED1
CTRL1
CTRL2
FB2
100k
0V
PWM
FREQ
5V
2m
s
/DIV
I
20mA/DIV
I
L
200mA/DIV
PWM
5V/DIV
349
8
F06
V
= 3V
4 LED
s
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LQH2MCN150K02 | 20mA LED Driver and OLED Driver with Integrated Schottky in 3mm x 2mm DFN |
| LQH32CN100K53 | 20mA LED Driver and OLED Driver with Integrated Schottky in 3mm x 2mm DFN |
| LQH32CN150K53 | 20mA LED Driver and OLED Driver with Integrated Schottky in 3mm x 2mm DFN |
| LQH31C | Dual Micropower DC/DC Converters with Schottky Diodes |
| LQH32C | Dual Micropower DC/DC Converters with Schottky Diodes |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LQH2MCN100K02L | 功能描述:固定電感器 Choke Circuit Coated 10uH RoHS:否 制造商:AVX 電感:10 uH 容差:20 % 最大直流電流:1 A 最大直流電阻:0.075 Ohms 工作溫度范圍:- 40 C to + 85 C 自諧振頻率:38 MHz Q 最小值:40 尺寸:4.45 mm W x 6.6 mm L x 2.92 mm H 屏蔽:Shielded 端接類型:SMD/SMT 封裝 / 箱體:6.6 mm x 4.45 mm |
| LQH2MCN100K02p | 制造商:MURATA 制造商全稱:Murata Manufacturing Co., Ltd. 功能描述:Chip Inductor (Chip Coil) Power Inductor (Wire Wound Type) LQH2MC_02 Series (0806 Size) |
| LQH2MCN100M52 | 制造商:MURATA 制造商全稱:Murata Manufacturing Co., Ltd. 功能描述:DESIGN ENGINEERING KITS |
| LQH2MCN100M52L | 功能描述:固定電感器 10uH 20% 1MHz RoHS:否 制造商:AVX 電感:10 uH 容差:20 % 最大直流電流:1 A 最大直流電阻:0.075 Ohms 工作溫度范圍:- 40 C to + 85 C 自諧振頻率:38 MHz Q 最小值:40 尺寸:4.45 mm W x 6.6 mm L x 2.92 mm H 屏蔽:Shielded 端接類型:SMD/SMT 封裝 / 箱體:6.6 mm x 4.45 mm |
| LQH2MCN120K02 | 制造商:MURATA 制造商全稱:Murata Manufacturing Co., Ltd. 功能描述:Chip Inductor (Chip Coil) Power Inductor (Wire Wound Type) LQH2MC_02 Series (0806 Size) |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。