- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44572 > LM5027AMHX (NATIONAL SEMICONDUCTOR CORP) SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO20 PDF資料下載
參數(shù)資料
| 型號： | LM5027AMHX |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO20 |
| 封裝： | TSSOP-20 |
| 文件頁數(shù)： | 16/28頁 |
| 文件大?。?/td> | 561K |
| 代理商： | LM5027AMHX |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁當前第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁
30111919
FIGURE 15. Resistor Current Sense
Soft-Start
The capacitor on the SS pin determines the time required for
the output duty cycle to increase from zero to its final value
for regulation. The minimum acceptable time is dependent on
the output capacitance and the response of the feedback loop
that controls the COMP pin. If the soft-start time is too quick,
the output could significantly overshoot its intended voltage
before the feedback loop has a chance to regulate the PWM
controller. After power is applied and VCC has passed its up-
per UV threshold (9.5V), the voltage at the SS pin ramps up
as the external capacitor is charged with an internal 20
μA
current source. The voltage at the internal PWM comparator
input node follows the voltage at the SS pin. When the voltage
on the SS pin has reached 1.0V, PWM pulses appear at the
drive output with a very low duty cycle. The voltage at the SS
pin eventually increases to approximately 5.0V. The voltage
at the input to the PWM comparator and the PWM duty cycle
increase to the value required for regulation as determined by
the voltage regulation loop.
Hiccup Mode Current Limit Restart
Hiccup mode operation is described in the Restart Time Delay
(Hiccup Mode) section. In the case of continuous current limit
detection at the CS pin, the time required to reach the 1.0V
RES pin threshold is:
For example, if C
approximately 2.14 ms. After the voltage on the RES pin
reaches 1.0V, the 22 A current source is turned-off and a 5
A current source is turned-on. The Hiccup Mode time is:
where
ΔV is 2.0V. With a C
RES = 0.047 F, the Hiccup Mode
time is 179 ms. After the Hiccup Mode off time is complete,
the RES pin voltage is pulled low and soft-start capacitor is
released allowing a soft-start sequence to commence.
The soft-start time t
restart is set by the internal 22 A current
source, and is equal to:
If C
SS = 0.1 F, trestart is = 6.41 ms
23
www.national.com
LM5027A
相關PDF資料 |
PDF描述 |
|---|---|
| LM5035AMH-1 | SWITCHING CONTROLLER, 2000 kHz SWITCHING FREQ-MAX, PDSO28 |
| LM5045MH | SWITCHING CONTROLLER, 540 kHz SWITCHING FREQ-MAX, PDSO28 |
| LM5045SQ | SWITCHING CONTROLLER, 540 kHz SWITCHING FREQ-MAX, QCC28 |
| LM5046SQ | SWITCHING CONTROLLER, 540 kHz SWITCHING FREQ-MAX, QCC28 |
| LM5046MHX | SWITCHING CONTROLLER, 540 kHz SWITCHING FREQ-MAX, PDSO28 |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| LM5027AMHX/NOPB | 功能描述:電壓模式 PWM 控制器 RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓撲結(jié)構:Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
| LM5027ASQ/NOPB | 功能描述:電壓模式 PWM 控制器 RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓撲結(jié)構:Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
| LM5027ASQX/NOPB | 功能描述:電壓模式 PWM 控制器 RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓撲結(jié)構:Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
| LM5027MH | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Voltage Mode Active Clamp Controller |
| LM5027MH/NOPB | 功能描述:電壓模式 PWM 控制器 Voltage Mode Active Clamp Controller RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓撲結(jié)構:Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復。