- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄43901 > L7980 (STMICROELECTRONICS) 3.5 A SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO8 PDF資料下載
參數(shù)資料
| 型號(hào)： | L7980 |
| 廠商： | STMICROELECTRONICS |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 3.5 A SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO8 |
| 封裝： | 3 X 3 MM, 1.08 MM HEIGHT, ROHS COMPLIANT, VFQFPN-8 |
| 文件頁數(shù)： | 10/44頁 |
| 文件大?。?/td> | 1247K |
| 代理商： | L7980 |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁當(dāng)前第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁
Application informations
L7980
18/44
Doc ID 15181 Rev 3
6.3
Output capacitor selection
The current in the capacitor has a triangular waveform which generates a voltage ripple
across it. This ripple is due to the capacitive component (charge or discharge of the output
capacitor) and the resistive component (due to the voltage drop across its ESR). So the
output capacitor has to be selected in order to have a voltage ripple compliant with the
application requirements.
The amount of the voltage ripple can be calculated starting from the current ripple obtained
by the inductor selection.
Equation 12
Usually the resistive component of the ripple is much higher than the capacitive one, if the
output capacitor adopted is not a multi layer ceramic capacitor (MLCC) with very low ESR
value.
The output capacitor is important also for loop stability: it fixes the double LC filter pole and
the zero due to its ESR. In Chapter 6.4, it will be illustrated how to consider its effect in the
system stability.
For example with VOUT=5 V, VIN=24 V, ΔIL=0.6 A (resulting by the inductor value), in order to
have a
ΔV
OUT=0.01VOUT, if the multi layer ceramic capacitor are adopted, 10 F are needed
and the ESR effect on the output voltage ripple can be neglected. In case of not negligible
ESR (electrolytic or tantalum capacitors), the capacitor is chosen taking into account its
ESR value. So in case of 220 with ESR=50 m
Ω, the resistive component of the drop
dominates and the voltage ripple is 33 mV
.
The output capacitor is also important to sustain the output voltage when a load transient
with high slew rate is required by the load. When the load transient slew rate exceeds the
system bandwidth the output capacitor provides the current to the load. So if the high slew
rate load transient is required by the application the output capacitor and system bandwidth
have to be chosen in order to sustain the load transient.
In the table below some capacitor series are listed.
Table 8.
Output capacitors
Manufacturer
Series
Cap value (
μF)
Rated voltage (V)
ESR (m
Ω)
MURATA
GRM32
22 to 100
6.3 to 25
< 5
GRM31
10 to 47
6.3 to 25
< 5
PANASONIC
ECJ
10 to 22
6.3
< 5
EEFCD
10 to 68
6.3
15 to 55
SANYO
TPA/B/C
100 to 470
4 to 16
40 to 80
TDK
C3225
22 to 100
6.3
< 5
ΔV
OUT
ESR
ΔI
MAX
ΔI
MAX
8C
OUT
f
SW
-------------------------------------
+
=
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| L7980TR | 3.5 A SWITCHING REGULATOR, 1000 kHz SWITCHING FREQ-MAX, PDSO8 |
| L7981ATR | SWITCHING REGULATOR, DSO8 |
| L7981TR | SWITCHING REGULATOR, DSO8 |
| L8219LP | STEPPER MOTOR CONTROLLER, 2.5 A, PDSO28 |
| L8219P | STEPPER MOTOR CONTROLLER, 2.5 A, PDSO36 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| L7980A | 制造商:STMicroelectronics 功能描述:Conv DC-DC Single Step Down 4.5V to 28V 8-Pin HSOP EP Tube 制造商:STMicroelectronics 功能描述:POWER CONVERSION - Rail/Tube 制造商:STMicroelectronics 功能描述:2A Step-Down Reg 2.5A 4.5 28V 250kHz 制造商:STMicroelectronics 功能描述:BUCK, 4.5-28V, 2A, 1MHZ, 0.6-28V, 8HSOP; Primary Input Voltage:28V; No. of Outputs:1; Output Current:2A; Voltage Regulator Case Style:HSOP; No. of Pins:8; Operating Temperature Min:-25C; Operating Temperature Max:125C; MSL:MSL 3 - ;RoHS Compliant: Yes 制造商:ST 功能描述:0 |
| L7980ATR | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 2 A Step-Down Reg 4.5V to 28V 250 kHz RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT |
| L7980TR | 功能描述:直流/直流開關(guān)轉(zhuǎn)換器 2A DC 4.5 V to 28 V Adj 0.6V 250 kHz RoHS:否 制造商:STMicroelectronics 最大輸入電壓:4.5 V 開關(guān)頻率:1.5 MHz 輸出電壓:4.6 V 輸出電流:250 mA 輸出端數(shù)量:2 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT |
| L7981 | 功能描述:直流/直流開關(guān)調(diào)節(jié)器 3A Step-Down Reg 3A DC 4.5-28V 250Khz RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(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 |
| L7981A | 制造商:STMicroelectronics 功能描述:POWER CONVERSION - Rail/Tube 制造商:STMicroelectronics 功能描述:3A Step-Down Reg 3.7A 4.5 to 28V 1MHz 制造商:ST 功能描述:3A STEP-DOWN SWITCHING REGULATOR |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。