- 您現(xiàn)在的位置：買(mǎi)賣(mài)IC網(wǎng) > PDF目錄384597 > LM3103MH (NATIONAL SEMICONDUCTOR CORP) SIMPLE SWITCHER㈢ Synchronous 1MHz 0.75A Step-Down Voltage Regulator PDF資料下載
參數(shù)資料
| 型號(hào)： | LM3103MH |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類(lèi)： | 穩(wěn)壓器 |
| 英文描述： | SIMPLE SWITCHER㈢ Synchronous 1MHz 0.75A Step-Down Voltage Regulator |
| 中文描述： | SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO16 |
| 封裝： | PLASTIC, TSSOP-16 |
| 文件頁(yè)數(shù)： | 11/16頁(yè) |
| 文件大小： | 304K |
| 代理商： | LM3103MH |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)當(dāng)前第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)
(5)
The LM3103 can be remotely shut down by pulling the voltage
of the EN pin below 1.6V. In this shutdown mode, the SS pin
is internally grounded, the on-timer is disabled, and bias cur-
rents are reduced. Releasing the EN pin allows normal oper-
ation to resume because the EN pin is internally pulled up.
30029726
FIGURE 1. Shutdown Implementation
Current Limit
Current limit detection is carried out during the off-time by
monitoring the re-circulating current through the synchronous
MOSFET. Referring to the Functional Block Diagram, when
the main MOSFET is turned off, the inductor current flows
through the load, the PGND pin and the internal synchronous
MOSFET. If this current exceeds 0.9A, the current limit com-
parator toggles, and as a result the start of the next on-time
period is disabled. The next switching cycle starts when the
re-circulating current falls back below 0.9A (and the voltage
at the FB pin is below 0.6V). The inductor current is monitored
during the on-time of the synchronous MOSFET. As long as
the inductor current exceeds 0.9A, the main MOSFET will re-
main inhibited to achieve current limit. The operating frequen-
cy is lower during current limit owing to a longer off-time.
Figure 2 illustrates an inductor current waveform. On aver-
age, the output current I
is the same as the inductor
current I
, which is the average of the rippled inductor current.
In case of current limit (the current limit portion of Figure 2),
the next on-time will not initiate until that the current drops
below 0.9A (assume the voltage at the FB pin is lower than
0.6V). During each on-time the current ramps up an amount
equal to:
(6)
During current limit, the LM3103 operates in a constant cur-
rent mode with an average output current I
OUT(CL)
equal to
0.9A + I
LR
/ 2.
30029728
FIGURE 2. Inductor Current - Current Limit Operation
11
www.national.com
L
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM3103MHX | SIMPLE SWITCHER㈢ Synchronous 1MHz 0.75A Step-Down Voltage Regulator |
| LM3204 | Miniature, Adjustable, Step-Down DC-DC Converter with Bypass Mode for RF Power Amplifiers |
| LM3204TL | Miniature, Adjustable, Step-Down DC-DC Converter with Bypass Mode for RF Power Amplifiers |
| LM3204TLX | Miniature, Adjustable, Step-Down DC-DC Converter with Bypass Mode for RF Power Amplifiers |
| LM3205 | 650mA Miniature, Adjustable, Step-Down DC-DC Converter for RF Power Amplifiers |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM3103MH/NOPB | 功能描述:直流/直流開(kāi)關(guān)轉(zhuǎn)換器 SYNC 1MHZ 0.75A STEP DOWN VLTG REG RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開(kāi)關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT |
| LM3103MHX | 制造商:Texas Instruments 功能描述:Conv DC-DC Single Step Down 4.5V to 42V 16-Pin TSSOP EP T/R |
| LM3103MHX/NOPB | 功能描述:直流/直流開(kāi)關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開(kāi)關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT |
| LM310H | 制造商:National Semiconductor 功能描述:310 NSC'83 SB51C 制造商:Texas Instruments 功能描述: 制造商:Rochester Electronics LLC 功能描述: |
| LM310H/A+ | 制造商:未知廠家 制造商全稱(chēng):未知廠家 功能描述:Analog Buffer/Voltage Follower |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。