- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄44551 > LM3075MTCX/NOPB (NATIONAL SEMICONDUCTOR CORP) SWITCHING CONTROLLER, 330 kHz SWITCHING FREQ-MAX, PDSO20 PDF資料下載
參數(shù)資料
| 型號： | LM3075MTCX/NOPB |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SWITCHING CONTROLLER, 330 kHz SWITCHING FREQ-MAX, PDSO20 |
| 封裝： | LEAD FREE, TSSOP-20 |
| 文件頁數(shù)： | 8/18頁 |
| 文件大?。?/td> | 857K |
| 代理商： | LM3075MTCX/NOPB |
Loop Compensation (Continued)
The control-output corner frequencies, and thus the desired
compensation corner frequencies, can be determined ap-
proximately by the following equations:
(20)
(21)
Since f
p is determined by the output network, it shifts with
loading (R
o) and duty cycle. First determine the range of
frequencies (f
pmin/max) of the pole across the expected load
range and then place the first compensation zero within that
range.
Example:R
esr
= 20m
,C
o
= 100uF, R
omax
= 5V/
100mA=50
,R
omin = 5V/5A = 1
,L =8H.
(22)
(23)
(24)
Once the f
p range is determined, Rc1 should be calculated
using:
(25)
Where B is the desired gain in V/V at f
p (fz1), gm is the
transconductance of the error amplifier, and R
1 and R2 are
the feedback resistors.
A gain value around 10dB (3.3V/V) is generally a good
starting point.
Example: B = 3.3 V/V, gm = 0.650 mho, R
1 =20k
,R
2 =
60.4 k
:
(26)
Bandwidth varies proportionally to the value of R
c1. Next,
C
c1 can be determined with the following equation :
(27)
Example: fpmin = 313Hz, R
c1 = 20k
:
(28)
The value of C
c1 should be within the range determined by
f
pmin/max. A higher value generally provides a more stable
loop, but too high a value slows the transient response time.
The compensation network also introduces a low frequency
pole that is close to 0Hz. A second pole should also be
placed at f
z. This pole can be created with a single capacitor
C
c2 and a shorted Rc2 (see Figure 9). The minimum value for
this capacitor can be calculated by:
(29)
C
c2 may not be necessary, however it does create a more
stable control loop. This is especially important with high
load currents and in current sharing mode.
Example: f
z = 36kHz, Rc1 = 20k
:
20162331
FIGURE 6. Control-Output Transfer Function
20162332
FIGURE 7. Output-Control Transfer Function
LM3075
www.national.com
16
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM3101N | SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDIP14 |
| LM3211MT-ADJ/NOPB | SWITCHING REGULATOR, 1500 kHz SWITCHING FREQ-MAX, PDSO20 |
| LM3311SQ-HIOP/NOPB | 2.6 A SWITCHING REGULATOR, 1280 kHz SWITCHING FREQ-MAX, QCC24 |
| LM3311SQ-HIOP | 2.6 A SWITCHING REGULATOR, 1280 kHz SWITCHING FREQ-MAX, QCC24 |
| LM3354MM-3.7/NOPB | SWITCHED CAPACITOR REGULATOR, 1400 kHz SWITCHING FREQ-MAX, PDSO10 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM3075N/A+ | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:FM Receiver Circuit |
| LM3075N/B+ | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:FM Receiver Circuit |
| LM3075N-01/A+ | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:FM Receiver Circuit |
| LM3075N-01/B+ | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:FM Receiver Circuit |
| LM307AH | 制造商:Texas Instruments 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。