參數(shù)資料
型號(hào): L5985
廠商: STMICROELECTRONICS
元件分類: 穩(wěn)壓器
英文描述: 2 A SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO8
封裝: 3 X 3 MM, 1.08 MM HEIGHT, LEAD FREE, VFQFPN-8
文件頁(yè)數(shù): 11/37頁(yè)
文件大小: 856K
代理商: L5985
L5985
Application information
Doc ID 13006 Rev 5
19/37
5.4.1
Type III compensation network
The methodology to stabilize the loop consists of placing two zeros to compensate the effect
of the LC double pole, so increasing phase margin; then to place one pole in the origin to
minimize the dc error on regulated output voltage; finally to place other poles far away the
zero dB frequency.
If the equivalent series resistance (ESR) of the output capacitor introduces a zero with a
frequency higher than the desired bandwidth (that is: 2
π * ESR * C
OUT < 1/BW), the type III
compensation network is needed. Multi layer ceramic capacitors (MLCC) have very low ESR
(< 1 m
Ω), with very high frequency zero, so type III network is adopted to compensate the
loop.
In Figure 10 the type III compensation network is shown. This network introduces two zeros
(fZ1, fZ2) and three poles (fP0, fP1, fP2). They expression are:
Equation 16
Equation 17
Figure 10.
Type III compensation network
In Figure 11 the Bode diagram of the PWM and LC filter transfer function (GPW0 GLC(f))
and the open loop gain (GLOOP(f) = GPW0 GLC(f) GTYPEIII(f)) are drawn.
f
Z1
1
2
π C
3
R
1
R
3
+
()
------------------------------------------------
=
f
Z2
1
2
π R
4
C
4
------------------------------
=
,
f
P0
0
=
f
P1
1
2
π R
3
C
3
------------------------------
=
f
P2
1
2
π R
4
C
4
C
5
C
4
C
5
+
--------------------
--------------------------------------------
=
,,
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L5985_08 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:2 A step-down switching regulator
L5985TR 功能描述:直流/直流開(kāi)關(guān)調(diào)節(jié)器 2a Step-Down Switching Reg RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開(kāi)關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
L5986 功能描述:直流/直流開(kāi)關(guān)調(diào)節(jié)器 2.5 A buck switching regulator RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開(kāi)關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
L5986A 功能描述:直流/直流開(kāi)關(guān)調(diào)節(jié)器 2.5 A STEP-DOWN SWITCH REG RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開(kāi)關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5
L5986ATR 功能描述:直流/直流開(kāi)關(guān)調(diào)節(jié)器 Step-down switch regulator, 2.5A RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開(kāi)關(guān)頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5