參數(shù)資料
型號： L6917BD
廠商： STMICROELECTRONICS
元件分類： 穩(wěn)壓器
英文描述： SWITCHING CONTROLLER, 600 kHz SWITCHING FREQ-MAX, PDSO28
封裝： SO-28
文件頁數(shù)： 10/33頁
文件大?。?/td> 631K
代理商： L6917BD
Obsolete
Product(s)
- Obsolete
Product(s)
L6917B
18/33
–ZF(s) is the compensation network impedance;
–ZL(s) is the parallel of the two inductor impedance;
– A(s) is the error amplifier gain;
–
is the ACM PWM transfer function where DVosc is the oscillator ramp amplitude
and has a typical value of 2V
Removing the dependence from the Error Amplifier gain, so assuming this gain high enough, the control loop
gain results:
With further simplifications, it results:
Considering now that in the application of interest it can be assumed that Ro>>RL; ESR<<Ro and
RDROOP<<Ro, it results:
The ACM control loop gain is designed to obtain a high DC gain to minimize static error and cross the 0dB axes
with a constant -20dB/dec slope with the desired crossover frequency
ωT. Neglecting the effect of ZF(s), the
transfer function has one zero and two poles. Both the poles are fixed once the output filter is designed and the
zero is fixed by ESR and the Droop resistance. To obtain the desired shape an RF-CF series network is consid-
ered for the ZF(s) implementation. A zero at ωF=1/RFCF is then introduced together with an integrator. This in-
tegrator minimizes the static error while placing the zero in correspondence with the L-C resonance a simple -
20dB/dec shape of the gain is assured (See Figure 12). In fact, considering the usual value for the output filter,
the LC resonance results to be at frequency lower than the above reported zero.
Figure 12. ACM Control Loop Gain Block Diagram (left) and Bode Diagram (right)
Compensation network can be simply designed placing
ωZ = ωLC and imposing the cross-over frequency ωT as
desired obtaining:
PWM
4
5
---
V
IN
V
OSC
-------------------
=
G
LOOP s
()
4
5
---
V
IN
V
OS C
-------------------
Z
F s
()
Z
P s
() Z
L s
()
+
------------------------------------
Rs
Rg
--------
Z
P s
()
R
FB
---------------
+
–
=
G
LOO P s
()
4
5
---
V
IN
V
OSC
-------------------
Z
F s
()
R
FB
---------------
Ro
R
DROOP
+
Ro
R
L
2
-------
+
--------------------------------------
1s Co
R
DROOP//Ro
ESR
+
()
+
s
2
Co
L
2
---
s
L
2R o
---------------
Co ESR
Co
R
L
2
-------
+
+
1
+
+
----------------------------------------------------------------------------------------------------------------------------------
–
=
G
LOO P s
()
4
5
---
V
IN
V
OSC
-------------------
Z
F s
()
R
FB
---------------
1s Co
R
DROOP
ESR
+
()
+
s
2
Co
L
2
---
s
L
2Ro
---------------
Co ESR
Co
R
L
2
-------
+
+
1
+
+
----------------------------------------------------------------------------------------------------------------------------------
–
=
Rout
Cout
ESR
L/2
RFB
RF
CF
REF
PWM
IFB
VCOMP
VOUT
d
VIN
ZF
dB
ω
T
ω
Z
ω
LC
GLOOP
ZF(s)
K
4
5
---
V
IN
V
osc
---------------
1
R
FB
----------
dB
=
相關PDF資料
PDF描述
L6917BDTR SWITCHING CONTROLLER, 600 kHz SWITCHING FREQ-MAX, PDSO28
L6917D SWITCHING CONTROLLER, 1000 kHz SWITCHING FREQ-MAX, PDSO28
L6918ADTR SWITCHING CONTROLLER, 1200 kHz SWITCHING FREQ-MAX, PDSO28
L6918AD SWITCHING CONTROLLER, 1200 kHz SWITCHING FREQ-MAX, PDSO28
L6919CD SWITCHING CONTROLLER, 200 kHz SWITCHING FREQ-MAX, PDSO28
相關代理商/技術參數(shù)
參數(shù)描述
L6917BDTR 功能描述:DC/DC 開關控制器 Prog Dual-Phase Cont RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風格: 封裝 / 箱體:CPAK
L6917D 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
L6917DTR 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Analog IC
L6918 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5 BIT PROGRAMMABLE MULTIPHASE CONTROLLER
L6918A 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:5 BIT PROGRAMMABLE MULTIPHASE CONTROLLER
發(fā)布緊急采購，3分鐘左右您將得到回復。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*