- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384857 > PWM5031 (Aeroflex Inc.) RadHard High Speed PWM Controller PDF資料下載
參數(shù)資料
| 型號： | PWM5031 |
| 廠商： | Aeroflex Inc. |
| 英文描述： | RadHard High Speed PWM Controller |
| 中文描述： | RadHard高速PWM控制器 |
| 文件頁數(shù)： | 13/17頁 |
| 文件大?。?/td> | 620K |
| 代理商： | PWM5031 |
13
SCD5031 Rev B
Peimnay
1.0Vdc
------------------
=
TYPICAL APPLICATIONS
A typical single output forward converter application is shown in Figure 9 to aid in the following operational description.
During normal operation, the oscillator jumpstarts each switching cycle by resetting the RS latch, causing the output
stage to go high and turn on M1. Current begins to build linearly through T1 and M1 and a proportional voltage is
developed across the small sense resistor Rs. Switching spikes are filtered by C1 and R1, and the resulting sawtooth
waveform is passed into the PWM to serve as the current comparator input. Meanwhile, a portion of the output voltage
is sensed and compared to the PWM’s internal precision 2.5V reference. The difference is then amplified and level
shifted to serve as the comparator threshold. When the voltage on the I
SENSE
pin exceeds this threshold, the comparator
fires and resets the latch. The output then turns off until the beginning of the next oscillator cycle when the process
repeats.
Like all current mode PWMs, the chip provides built in fault protection by limiting peak switch current on a cycle by
cycle basis. When an overload condition occurs, the sensed current reaches the current trip threshold earlier in the
switching cycle than it otherwise would and thus forces the PWM latch off until the start of the next cycle. The process
repeats until the overload condition is removed and the PWM can return to a normal duty cycle. The chip is capable of
operating in this mode indefinitely without sustaining damage.
There are two ways to set the current limit trip point. One is to simply tailor the sense resistor Rs:
Some users may find the power is dissipated in Rs to be unacceptably high. In this case, the user can fix Rs at a small
value and vary the current comparator threshold instead. Fortunately, the PWM chip provides a very convenient method
for doing so. Because the error amplifier output is internally clamped to the SOFT pin, the user need simply apply the
desired voltage level to the SOFT pin to arbitrarily lower the current comparator threshold.
FIGURE 9 – Typical Forward Converter Application
Rset
Cset
C
SOFT
0.1μF
R
SOFT
M2
C1
R1
Rs
T1
Isolation Barrier
3.3V, 0.5A
Opto-Isolator or
Pulse Transformer
Optional circuit
to force zero
duty cycle
M1
R
SET
C
SET
V
EE
DRVN
V
FB
COMP
50%
I
SENSE
Out A
Out B
V
CC
DRVP
EN
SOFT
V
REF
+5V
DC
I
pk
R
s
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| PWM5031-7 | RadHard High Speed PWM Controller |
| PWM5031-I | RadHard High Speed PWM Controller |
| PWM5031-S | RadHard High Speed PWM Controller |
| PWRL | Low Resistance Stand-up Power Wirewound Resistor |
| R1140Q281B-TL | SC82 120mA LDO REGULATOR |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| PWM5031-7 | 制造商:AEROFLEX 制造商全稱:AEROFLEX 功能描述:RadHard High Speed PWM Controller |
| PWM5031-I | 制造商:AEROFLEX 制造商全稱:AEROFLEX 功能描述:RadHard High Speed PWM Controller |
| PWM5031-S | 制造商:AEROFLEX 制造商全稱:AEROFLEX 功能描述:RadHard High Speed PWM Controller |
| PWM505 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC |
| PWM-50-59 | 制造商:Brady Corporation 功能描述:REFILL PAGES - LEGEND: 50-59 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。