- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄382355 > MX841 (IXYS Corporation) White LED Step-Up Converter PDF資料下載
參數(shù)資料
| 型號(hào)： | MX841 |
| 廠商： | IXYS Corporation |
| 英文描述： | White LED Step-Up Converter |
| 中文描述： | 白光LED升壓轉(zhuǎn)換器 |
| 文件頁數(shù)： | 4/6頁 |
| 文件大小： | 202K |
| 代理商： | MX841 |
Preliminary
MX841
Drawing No. 17023
03/10/05
www.ixys.net
MX841
Functional Description
The MX841 is specifically designed to be
operated from a single cell battery source. The
step-up voltage necessary for the constant
current source to drive up to 5 white LED’s in
series, or multiple strings of white LED’s, is
achieved with minimal external components. (See
Application Schematics on pages 1&4).
Setting the LED Current
The regulated output current is determined by the
selection of the sense Resistor connected from
the I
SENSE
input to ground, and the maximum user
defined voltage of the CTRL input. The desired
output current, (typically 15mA to 20mA for white
LEDs), is derived using the following formula for
the R
SENSE
value: R
SENSE
= (V
CTRL
X 1/13) / I
LED
.
Current Regulation / Light Intensity Control
The
I
SENSE
voltage
ErrorAmp/Comparator. The user defined Control
Voltage applied at the CTRL input is scaled by a
gain factor of 1/13 and compared to the I
SENSE
voltage. If the scaled control voltage is greater
than the I
SENSE
voltage, the 1.0MHz oscillator
signal driving the N-Channel MOSFET will be
enabled. Once the I
SENSE
voltage reaches the
scaled CTRL voltage the oscillator signal is
modulated
on
and
ErrorAmp/Comparator to maintain the desired
regulated output current.
IXYS
is
fed
into
an
off
by
the
Light intensity is controlled by reducing the
voltage at the CTRL input. As the CTRL input
voltage is reduced below the user defined
maximum value, the oscillator signal driving the
N-Channel MOSFET is interrupted by the
ErrorAmp/Comparator. The pulse skip modulating
of the N-Channel MOSFET causes a reduction in
the regulated current equal to the ratio of the
reduced CTRL voltage to the maximum CTRL
voltage.
Sleep Mode
The MX841 goes into sleep mode when the V
CTRL
input is less than 100mV. All circuits except V
CTRL
detection are shutdown and the supply current
falls to 6uA. Once the V
CTRL
input rises above
260mV the MX841 resumes normal operation.
Over Voltage Detection
The MX841 will go into a shutdown state to avoid
an over voltage condition if the current path
between the SW output and the R
SENSE
input is
interrupted. A voltage reference and comparator
circuit evaluates the voltage potential at the OVD
input and shuts down the oscillator and N-
Channel MOSFET if an over voltage condition is
detected. Normal operation is resumed once the
OVD input voltage falls below the reference
voltage, (20V typical).
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MX88L284AEC | Highly integration chip for Flat Panel Display application |
| MXA2500U | Ultra Low Noise, 1g Dual Axis Accelerometer with Analog Outputs |
| MXA28A | MOLDED TSSOP JEDEC |
| MXA6500EP | Low Profile, Low Consumption 0.5 g Dual Axis Accelerometer with Absolute Analog Outputs |
| MXF10A | 1W Monaural, 85mW Stereo Headphone Audio Amplifier |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MX841BE | 功能描述:LED照明驅(qū)動(dòng)器 Amps V RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SO-16N |
| MX841BETR | 功能描述:LED照明驅(qū)動(dòng)器 Amps V RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SO-16N |
| MX842RS | 制造商:BCM Advanced Research 功能描述:ATI RS842 CHIPS SEMPRON/TURION 1GIG DDR 10/100 2COM 8USB - Bulk |
| MX844 | 制造商:IXYS 制造商全稱:IXYS Corporation 功能描述:12 BIT, MULTI-CHANNEL POWER & TEMP SENSOR FOR MONITOR & CONTROL SYSTEMS |
| MX844R | 功能描述:板上安裝溫度傳感器 12-Bit Power & Temp Sensor QFN-28 RoHS:否 制造商:Omron Electronics 輸出類型:Digital 配置: 準(zhǔn)確性:+/- 1.5 C, +/- 3 C 溫度閾值: 數(shù)字輸出 - 總線接口:2-Wire, I2C, SMBus 電源電壓-最大:5.5 V 電源電壓-最小:4.5 V 最大工作溫度:+ 50 C 最小工作溫度:0 C 關(guān)閉: 安裝風(fēng)格: 封裝 / 箱體: 設(shè)備功能:Temperature and Humidity Sensor |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。