- 您現在的位置：買賣IC網 > PDF目錄358219 > MP8640DL (MONOLITHIC POWER SYSTEMS INC) SWITCHING REGULATOR, 800 kHz SWITCHING FREQ-MAX, DSO14 PDF資料下載
參數資料
| 型號： | MP8640DL |
| 廠商： | MONOLITHIC POWER SYSTEMS INC |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SWITCHING REGULATOR, 800 kHz SWITCHING FREQ-MAX, DSO14 |
| 封裝： | 3 X 4 MM, MO-229VGED-3, QFN-14 |
| 文件頁數： | 8/10頁 |
| 文件大?。?/td> | 351K |
| 代理商： | MP8640DL |
MP8640 – 3A, 23V, 600KHz STEP-DOWN WITH SYNCHRONOUS GATE DRIVER
MP8640 Rev. 1.0
12/13/2007
www.MonolithicPower.com
8
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
2007 MPS. All Rights Reserved.
APPLICATION INFORMATION
Setting the Output Voltage
The external resistor divider is used to set the
output voltage (see the schematic on front
page). The feedback resistor R1 also sets the
feedback loop bandwidth with the internal
compensation capacitor (see Figure 1). Choose
R1 to be around 40.2k
for optimal transient
response. R2 is then given by:
1
V
8
V
1
R
2
R
OUT
=
Table 1—Resistor Selection for Common
Output Voltages
V
OUT
(V)
1.8
2.5
3.3
5
R1 (k
)
40.2 (1%)
40.2 (1%)
40.2 (1%)
40.2 (1%)
R2 (k
)
32.4 (1%)
19.1 (1%)
13 (1%)
7.68 (1%)
Selecting the Inductor
A 1μH to 10μH inductor with a DC current rating
of at least 25% percent higher than the
maximum load current is recommended for
most applications. For highest efficiency, the
inductor DC resistance should be less than
15m
. For most designs, the inductance value
can be derived from the following equation.
OSC
L
IN
OUT
V
IN
I
OUT
V
f
)
V
Δ
(
V
L
×
×
×
=
Where
Δ
I
L
is the inductor ripple current.
Choose inductor current to be approximately
30% if the maximum load current, 3A. The
maximum inductor peak current is:
2
I
I
I
L
LOAD
)
MAX
(
L
Δ
+
=
Under light load conditions below 100mA, larger
inductance is recommended for improved
efficiency.
Synchronous MOSFET
The external synchronous MOSFET is used to
supply current to the inductor when the internal
high-side switch is off. It reduces the power loss
significantly when compared against a Schottky
rectifier.
Table 2 lists example synchronous MOSFETs
and manufacturers.
Table 2—Synchronous MOSFET Selection
Guide
Part No.
Si7112
Si7114
AM4874
Manufacture
Vishay
Vishay
Analog Power
Selecting the Input Capacitor
The input current to the step-down converter is
discontinuous, therefore a capacitor is required to
supply the AC current to the step-down converter
while maintaining the DC input voltage. Use low
ESR capacitors for the best performance. Ceramic
capacitors with X5R or X7R dielectrics are
highly recommended because of their low ESR
and small temperature coefficients. For most
applications, a 10μF capacitor is sufficient.
Since the input capacitor (C1) absorbs the input
switching current it requires an adequate ripple
current rating. The RMS current in the input
capacitor can be estimated by:
×
1
×
=
IN
OUT
V
IN
OUT
V
LOAD
1
C
V
V
I
I
The worse case condition occurs at V
IN
= 2V
OUT
,
where:
I
I
1
2
LOAD
C
=
For simplification, choose the input capacitor
whose RMS current rating greater than half of
the maximum load current.
相關PDF資料 |
PDF描述 |
|---|---|
| MPA62-FREQ-OUT23 | CRYSTAL OSCILLATOR, CLOCK, 16 MHz - 150 MHz, CMOS/TTL OUTPUT |
| MPA64R-FREQ-OUT23 | CRYSTAL OSCILLATOR, CLOCK, 16 MHz - 105 MHz, CMOS/TTL OUTPUT |
| MPA63R-FREQ-OUT23 | CRYSTAL OSCILLATOR, CLOCK, 16 MHz - 105 MHz, CMOS/TTL OUTPUT |
| MPG4375S-J220KB | SINGLE COLOR LED, GREEN, 4 mm |
| MPN-2/BNC | PANEL MOUNT, FEMALE, BNC CONNECTOR, RECEPTACLE |
相關代理商/技術參數 |
參數描述 |
|---|---|
| MP8640DL-LF-P | 功能描述:開關變換器、穩(wěn)壓器與控制器 3A 23V 600kHz Step Dwn w/Sync Gate Drvr RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel |
| MP8640DL-LF-Z | 功能描述:開關變換器、穩(wěn)壓器與控制器 3A 23V 600kHz Step Dwn w/Sync Gate Drvr RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel |
| MP8642DU-LF-P | 功能描述:開關變換器、穩(wěn)壓器與控制器 Dual 3A, 23V 600kHz Step-Down RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel |
| MP8642DU-LF-Z | 功能描述:開關變換器、穩(wěn)壓器與控制器 Dual 3A, 23V 600kHz Step-Down RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel |
| MP8666DN-LF | 功能描述:開關變換器、穩(wěn)壓器與控制器 6A, 600kHz Step-Down w/Sync Gate Driver RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復。