- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄97995 > L6615N (STMICROELECTRONICS) 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDIP8 PDF資料下載
參數(shù)資料
| 型號： | L6615N |
| 廠商： | STMICROELECTRONICS |
| 元件分類： | 電源管理 |
| 英文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDIP8 |
| 封裝： | MINI, DIP-8 |
| 文件頁數(shù)： | 5/20頁 |
| 文件大?。?/td> | 394K |
| 代理商： | L6615N |
13/20
L6615
The last point is the design of the compensation network ZC(s) connected between the COMP pin and
ground.
Besides the power supply feedback loop, the current sharing system introduces another, outer loop. To
avoid interaction between them it is important to design the bandwidth of the sharing loop at least one or-
der of magnitude lower than the bandwidth of the power supply loop.
For the total system, the loop gain is:
where
APWR(s) is the transfer function of PWM controller and power stage (see fig. 11)
RLOAD is the equivalent load resistance
Typically the compensation network is built by a R-C series.
A resistor in series with CC is required to boost the phase margin of the load share loop. The zero is placed
at the load share loop crossover frequency, fC(SH).
If fC(SH) is the share loop crossover frequency, then:
5
CURRENT SENSE METHODS
Several are the methods to sense the power supply output current; the simplest one is to use a power
resistor (fig. 13a) but increasing load current could require expensive resistor to support the inherent pow-
er dissipation, imposing the use of several paralleled resistor.
Other methods to sense the output current are showed in fig. 13b and 13c:
1. RDS(ON): a power MOS is placed in series to the output and its channel resistance (RDS(ON)) is used
as sense resistor (fig 13a): the L6615 sense pins will be connected, through RG resistors to the drain
and to the source of the MOS. Besides providing the sense resistor, the FET is used as "ORing" el-
ement: driving properly its gate, it is possible isolate the power supply output from the load (the body
diode is reversed biased so it doesn't conduct).
This is useful whenever features like hot swap or hot plug are required; compared with the well-known
solution using ORing diode, the ORing FET greatly reduces the power dissipation, in particular:
where VF is the forward drop across the diode.
2. Current transformer: in case of very high load currents, a transformer allows sensing a smaller cur-
rent, obtained through a scaling factor equal to the transformer turn ratio. In this way, the sense re-
sistor power dissipation requirements can be less tight: obviously this is paid with the cost of the
transformer.
In fig. 13c it is showed the simplified output stage of a power supply in forward configuration: through
two current transformers the load current is reproduced in the sensing circuit scaled by a factor N.
RSENSE will read a ripple (at the switching frequency) superimposed on the average current value
that doesn't affect the correct behaviour of the current sharing system because its loop gain is de-
signed with a low bandwidth - at least 2 order of magnitude lower than the switching frequency - that
will cut this high frequency.
G
LOOP s
()
R
SENSE
R
CGA
R
G
--------------- G
M ZC s
()
R
ADJ
R
A
-------------- A
PWR s
()
1
R
LOA D
------------------
=
C
1
2
π f
CSH
()
--------------------------------
R
CGA
G
M
R
G
-----------------------------
R
ADJ
R
A
--------------
R
SENSE
R
LOAD
----------------------
A
PW R f
CSH
()
=
R
C
1
2
π f
CSH
() CC
---------------------------------------------
=
P
DIO DE
()
V
F
I
OUT
R
SE NSE
I
OUT
2
+
=
P
MOS
()
R
DS O N
() IOUT
2
=
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| L6711TR | 2 A SWITCHING CONTROLLER, 178 kHz SWITCHING FREQ-MAX, PQFP48 |
| L6711 | 2 A SWITCHING CONTROLLER, 178 kHz SWITCHING FREQ-MAX, PQFP48 |
| L6714TR | SWITCHING CONTROLLER, 170 kHz SWITCHING FREQ-MAX, PQFP64 |
| L6714 | SWITCHING CONTROLLER, 170 kHz SWITCHING FREQ-MAX, PQFP64 |
| L6725TR | 20 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| L6622-01 | 制造商:HAMAMATSU 制造商全稱:Hamamatsu Corporation 功能描述:130 KV MICROFOCUS X-RAY SOURCE |
| L-663 | 制造商:RHOMBUS-IND 制造商全稱:Rhombus Industries Inc. 功能描述:CURRENT SENSE INDUCTOR |
| L6-6330 | 制造商: 功能描述: 制造商:undefined 功能描述: |
| L6660 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:MILLI-ACTUATOR DRIVER |
| L6668 | 功能描述:電流型 PWM 控制器 SMART PRIMARY CONTROLLER RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。