- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384598 > LM3407MY (NATIONAL SEMICONDUCTOR CORP) 350 mA, Constant Current Output Floating Buck Switching Converter for High Power LEDs PDF資料下載
參數(shù)資料
| 型號： | LM3407MY |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 顯示驅(qū)動器 |
| 英文描述： | 350 mA, Constant Current Output Floating Buck Switching Converter for High Power LEDs |
| 中文描述： | LED DISPLAY DRIVER, PDSO8 |
| 封裝： | PLASTIC, MSOP-8 |
| 文件頁數(shù)： | 9/16頁 |
| 文件大小： | 321K |
| 代理商： | LM3407MY |
30046620
FIGURE 2. LM3407 Switching Waveforms
The switching frequency and duty ratio of the converter equal:
By comparing the area of V
and V
over the ON period,
an error signal is generated. Such a comparison is function-
ally equivalent to comparing the middle level of I
to V
during the ON-period of a switching cycle. The error signal is
fed to a PWM comparator circuit to produce the PWM control
pulse to drive the internal power N-MOSFET.
Figure 3
shows
the implementation of the PWM switching signal. The error
signal is fed to a PWM comparator circuit to produce the PWM
control pulse to drive the internal power N-MOSFET.
Figure
3
shows the implementation of the PWM switching signal.
In closed loop operation, the difference between V
and
V
is reflected in the changes of the switching duty cycle of
the power switch. This behavior is independent of the induc-
tance of the inductor and input voltage because for the same
set of I
* R
ISNS
, ON time, and switching period, there exists
only one V
shows two sets of current sense sig-
nals named V
and V
that have identical frequencies
and duty cycles but different shapes of trapezoidal wave-
forms, each generating identical PWM signals.
30046623
FIGURE 3. Pulse-Level Transformation
When V
is higher than V
, the peak value of V
, the
switching duty cycle of the power switch will be reduced to
lower V
. When V
is lower than the peak value of V
,
the switching duty cycle of the power switch will be increased
to raise V
. For example, when I
is decreased, V
will
become lower than V
. In order to maintain output current
regulation, the switching duty cycle of the power switch will
be increased and eventually push up V
until V
MSL
equals
V
REF
. Since in typical floating buck regulators V
is equal
to I
* R
, true average output current regulation can be
achieved by regulating V
.
Figure 5
shows the waveforms
of V
ISNS
and V
RP
under closed loop operation.
9
www.national.com
L
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM3407MYX | 350 mA, Constant Current Output Floating Buck Switching Converter for High Power LEDs |
| LM3410YSDX | 525kHz/1.6MHz, Constant Current Boost and SEPIC LED Driver with Internal Compensation |
| LM3410 | 525kHz/1.6MHz, Constant Current Boost and SEPIC LED Driver with Internal Compensation |
| LM3410XMF | 525kHz/1.6MHz, Constant Current Boost and SEPIC LED Driver with Internal Compensation |
| LM3410XMFX | 525kHz/1.6MHz, Constant Current Boost and SEPIC LED Driver with Internal Compensation |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM3407MY/NOPB | 功能描述:開關(guān)變換器、穩(wěn)壓器與控制器 350MA,CONST CRNT OUT SWITCHING CONVERTER RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關(guān)頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel |
| LM3407MYX | 制造商:Texas Instruments 功能描述:Conv DC-DC Single Step Down 4.5V to 30V 8-Pin MSOP EP T/R |
| LM3407MYX/NOPB | 功能描述:開關(guān)變換器、穩(wěn)壓器與控制器 RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關(guān)頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel |
| LM3409 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:PFET Buck Controller for High Power LED Drives |
| LM3409_10 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:PFET Buck Controller for High Power LED Drives |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。