- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44546 > LM25574Q0MT (NATIONAL SEMICONDUCTOR CORP) SWITCHING REGULATOR, PDSO16 PDF資料下載
參數(shù)資料
| 型號： | LM25574Q0MT |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SWITCHING REGULATOR, PDSO16 |
| 封裝： | TSSOP-16 |
| 文件頁數(shù)： | 7/20頁 |
| 文件大?。?/td> | 394K |
| 代理商： | LM25574Q0MT |
24.9k
. These values configure the compensation network
zero at 290Hz. The error amp gain at frequencies greater than
f
Z is: R4 / R5, which is approximately 5 (14dB).
30071016
FIGURE 10. Error Amplifier Gain and Phase
The overall loop can be predicted as the sum (in dB) of the
modulator gain and the error amp gain.
30071017
FIGURE 11. Overall Loop Gain and Phase
If a network analyzer is available, the modulator gain can be
measured and the error amplifier gain can be configured for
the desired loop transfer function. If a network analyzer is not
available, the error amplifier compensation components can
be designed with the guidelines given. Step load transient
tests can be performed to verify acceptable performance. The
step load goal is minimum overshoot with a damped re-
sponse. C6 can be added to the compensation network to
decrease noise susceptibility of the error amplifier. The value
of C6 must be sufficiently small since the addition of this ca-
pacitor adds a pole in the error amplifier transfer function. This
pole must be well beyond the loop crossover frequency. A
good approximation of the location of the pole added by C6
is: f
p2 = fz x C5 / C6.
BIAS POWER DISSIPATION REDUCTION
Buck regulators operating with high input voltage can dissi-
pate an appreciable amount of power for the bias of the IC.
The V
CC regulator must step-down the input voltage VIN to a
nominal V
CC level of 7V. The large voltage drop across the
V
CC regulator translates into a large power dissipation within
the Vcc regulator. There are several techniques that can sig-
nificantly reduce this bias regulator power dissipation. Figure
output voltage. In each case the internal Vcc regulator is used
to initially bias the VCC pin. After the output voltage is estab-
lished, the VCC pin potential is raised above the nominal 7V
regulation level, which effectively disables the internal V
CC
regulator. The voltage applied to the VCC pin should never
exceed 14V. The V
CC voltage should never be larger than the
V
IN voltage.
15
www.national.com
LM25574Q0
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM25574Q0MTX | SWITCHING REGULATOR, PDSO16 |
| LM25576Q0MH | SWITCHING REGULATOR, PDSO20 |
| LM2574HVADJMWC | 1.8 A SWITCHING REGULATOR, 63 kHz SWITCHING FREQ-MAX, UUC |
| LM2574HVN-3.3/NOPB | 1.8 A SWITCHING REGULATOR, 63 kHz SWITCHING FREQ-MAX, PDIP8 |
| LM2574-5.0MWC | 1.8 A SWITCHING REGULATOR, 63 kHz SWITCHING FREQ-MAX, UUC |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM25574Q0MT/NOPB | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(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 |
| LM25574Q0MTX | 制造商:TI 制造商全稱:Texas Instruments 功能描述:LM25574/LM25574-Q1 SIMPLE SWITCHER 42V, 0.5A Step-Down Switching Regulator |
| LM25574Q0MTX/NOPB | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(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 |
| LM25574-Q1 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:LM25574/LM25574-Q1 SIMPLE SWITCHER 42V, 0.5A Step-Down Switching Regulator |
| LM25574QMT | 制造商:TI 制造商全稱:Texas Instruments 功能描述:LM25574/LM25574-Q1 SIMPLE SWITCHER 42V, 0.5A Step-Down Switching Regulator |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。