參數(shù)資料
型號(hào)： LM3311SQ
廠商： NATIONAL SEMICONDUCTOR CORP
元件分類： 穩(wěn)壓器
英文描述： Step-Up PWM DC/DC Converter with Integrated LDO, Op-Amp, and Gate Pulse Modulation Switch
中文描述： 2.6 A SWITCHING REGULATOR, 1280 kHz SWITCHING FREQ-MAX, QCC24
封裝： LLP-24
文件頁(yè)數(shù)： 18/29頁(yè)
文件大?。?/td> 2052K
代理商： LM3311SQ
Operation
CONTINUOUS CONDUCTION MODE
The LM3311 contains a current-mode, PWM boost regulator.
A boost regulator steps the input voltage up to a higher
output voltage. In continuous conduction mode (when the
inductor current never reaches zero at steady state), the
boost regulator operates in two cycles.
In the first cycle of operation, shown in
Figure 1
(a), the
transistor is closed and the diode is reverse biased. Energy
is collected in the inductor and the load current is supplied by
C
OUT
.
The second cycle is shown in
Figure 1
(b). During this cycle,
the transistor is open and the diode is forward biased. The
energy stored in the inductor is transferred to the load and
output capacitor.
The ratio of these two cycles determines the output voltage.
The output voltage is defined approximately as:
where D is the duty cycle of the switch, D and D' will be
required for design calculations.
SETTING THE OUTPUT VOLTAGE (BOOST
CONVERTER AND LDO)
The output voltage is set using the feedback pin and a
resistor divider connected to the output as shown in the
typical operating circuit. The feedback pin voltage is 1.263V
for both the boost regulator and the LDO, so the ratio of the
feedback resistors sets the output voltage according to the
following equations:
SOFT-START CAPACITOR
The LM3311 has a soft-start pin that can be used to limit the
inductor inrush current on start-up. The external SS pin is
used to tailor the soft-start for a specific application (see the
Linear Regulator (LDO)
section for the minimum value of
C
SS
). When used, a current source charges the external
soft-start capacitor C
SS
until it reaches its typical clamp
voltage, V
SS
. The soft-start time can be estimated as:
T
SS
= C
SS
*V
SS
/I
SS
THERMAL SHUTDOWN
The LM3311 includes thermal shutdown. If the die tempera-
ture reaches 145C the device will shut down until it cools to
a safe temperature at which point the device will resume
operation. If the adverse condition that is heating the device
is not removed (ambient temperature too high, short circuit
conditions, etc...) the device will continue to cycle on and off
to keep the die temperature below 145C. The thermal shut-
down has approximately 20C of hysteresis. When in ther-
mal shutdown the boost regulator, LDO, Op-Amp, and GPM
blocks will all be disabled.
20126302
FIGURE 1. Simplified Boost Converter Diagram
(a) First Cycle of Operation (b) Second Cycle Of Operation
L
www.national.com
18
相關(guān)PDF資料
PDF描述
LM3354MMX-5.0 Regulated 90mA Buck-Boost Switched Capacitor DC/DC Converter
LM3354MMX-4.1 Regulated 90mA Buck-Boost Switched Capacitor DC/DC Converter
LM3354MM-1.8 Regulated 90mA Buck-Boost Switched Capacitor DC/DC Converter
LM3354MM-3.3 Regulated 90mA Buck-Boost Switched Capacitor DC/DC Converter
LM3354MM-3.7 Regulated 90mA Buck-Boost Switched Capacitor DC/DC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LM3311SQ/NOPB 功能描述:IC REG BOOST ADJ 2A DL 24LLP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:- 類型:降壓（降壓） 輸出類型:固定 輸出數(shù):1 輸出電壓:3.3V 輸入電壓:4.5 V ~ 24 V PWM 型:- 頻率 - 開關(guān):- 電流 - 輸出:125mA 同步整流器:無(wú) 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SOT-23-6 包裝:Digi-Reel® 供應(yīng)商設(shè)備封裝:SOT-6 其它名稱:MAX1836EUT33#TG16DKR
LM3311SQ-HIOP 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
LM3311SQ-HIOP/NOPB 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
LM3311SQX 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
LM3311SQX/NOPB 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*