- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385522 > MAX1720 (ON SEMICONDUCTOR) Switched Capacitor Voltage Inverter with Shutdown(帶關(guān)斷功能的開關(guān)電容電壓反相器) PDF資料下載
參數(shù)資料
| 型號(hào)： | MAX1720 |
| 廠商： | ON SEMICONDUCTOR |
| 元件分類： | 基準(zhǔn)電壓源/電流源 |
| 英文描述： | Switched Capacitor Voltage Inverter with Shutdown(帶關(guān)斷功能的開關(guān)電容電壓反相器) |
| 中文描述： | SOT23封裝、開關(guān)電容電壓反相器，帶有關(guān)斷 |
| 文件頁數(shù)： | 5/18頁 |
| 文件大?。?/td> | 182K |
| 代理商： | MAX1720 |
MAX1720
http://onsemi.com
5
6
4
2
3
1
OSC
V
out
C
1
C
2
+
R
L
+
+C
3
V
in
Figure 14. Test Setup/Voltage Inverter
5
C
1
= C
2
= C
3
= 10 F
DETAILED OPERATING DESCRIPTION
The MAX1720 charge pump converter inverts the voltage
applied to the V
in
pin. Conversion consists of a twophase
operation (Figure 15). During the first phase, switches S
2
and
S
4
are open and S
1
and S
3
are closed. During this time, C
1
charges to the voltage on V
in
and load current is supplied from
C
2
. During the second phase, S
2
and S
4
are closed, and S
1
and
S
3
are open. This action connects C
1
across C
2
, restoring
charge to C
2
.
Figure 15. Ideal Switched Capacitor Charge Pump
S3
S4
C
2
C
1
S1
S2
V
in
V
out
From Osc
APPLICATIONS INFORMATION
Output Voltage Considerations
The MAX1720 performs voltage conversion but does not
provide regulation. The output voltage will drop in a linear
manner with respect to load current. The value of this
equivalent output resistance is approximately 26 nominal
at 25
°
C with V
in
= 5.0 V. V
out
is approximately 5.0 V at light
loads, and drops according to the equation below:
VDROP
Vout
Iout
Rout
VDROP)
(Vin
Charge Pump Efficiency
The overall power conversion efficiency of the charge
pump is affected by four factors:
1. Losses from power consumed by the internal
oscillator, switch drive, etc. (which vary with input
voltage, temperature and oscillator frequency).
2. I
2
R losses due to the onresistance of the MOSFET
switches onboard the charge pump.
3. Charge pump capacitor losses due to Equivalent
Series Resistance (ESR).
4. Losses that occur during charge transfer from the
commutation capacitor to the output capacitor when
a voltage difference between the two capacitors
exists.
Most of the conversion losses are due to factors 2, 3 and 4.
These losses are given by Equation 1.
PLOSS(2,3,4)
Iout
2
Rout
Iout
2
1
(fOSC)C1
8RSWITCH
4ESRC1
ESRC2
(eq. 1)
The 1/(f
OSC
)(C
1
) term in Equation 1 is the effective output
resistance of an ideal switched capacitor circuit (Figures 16
and 17).
The losses due to charge transfer above are also shown in
Equation 2. The output voltage ripple is given by Equation 3.
0.5C2(VRIPPLE
2
2VoutVRIPPLE)]
fOSC
PLOSS
[ 0.5C1(Vin
2
Vout
2
)
(eq. 2)
VRIPPLE
Iout
(fOSC)(C2)
2(Iout)(ESRC2)
(eq. 3)
R
L
C
2
C
1
V
in
V
out
f
Figure 16. Ideal Switched Capacitor Model
R
L
C
2
V
in
V
out
R
EQUIV
REQUIV
1
f
C1
Figure 17. Equivalent Output Resistance
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX173 | Complete 5μs CMOS 12Bits ADC(CMOS，5μs,單通道，10位ADC) |
| MAX174 | 12 Bits ADC(工業(yè)標(biāo)準(zhǔn)，單通道，12位ADC) |
| MAX176 | Serial Output 12 Bits ADC(串行輸出，250ksps,串行，12位ADC) |
| MAX1790 | Low-Noise Step-Up DC-DC Converter(低噪聲步升DC-DC轉(zhuǎn)換器) |
| MAX1802 | Digital Camera Step-Down Power Supply |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX1720EUT | 功能描述:電荷泵 Switched Cap Voltage RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 輸出電壓:- 1.5 V to - 5.5 V, 3 V to 11 V 輸出電流:100 mA 電源電流:1 mA 最大工作溫度:+ 70 C 封裝 / 箱體:SOIC-8 Narrow 封裝:Tube |
| MAX1720EUT+ | 制造商:Maxim Integrated Products 功能描述:CHG PUMP INV -1.25V TO -5.5V 25MA 6PIN SOT-23 - Rail/Tube |
| MAX1720EUT+T | 功能描述:電荷泵 Switched-Cap Voltage Inverter w/Shutdown RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 輸出電壓:- 1.5 V to - 5.5 V, 3 V to 11 V 輸出電流:100 mA 電源電流:1 mA 最大工作溫度:+ 70 C 封裝 / 箱體:SOIC-8 Narrow 封裝:Tube |
| MAX1720EUTG | 功能描述:電荷泵 Switched Cap Voltage Inverter w/Shutdown RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 輸出電壓:- 1.5 V to - 5.5 V, 3 V to 11 V 輸出電流:100 mA 電源電流:1 mA 最大工作溫度:+ 70 C 封裝 / 箱體:SOIC-8 Narrow 封裝:Tube |
| MAX1720EUT-T | 功能描述:電荷泵 Switched-Cap Voltage Inverter w/Shutdown RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 輸出電壓:- 1.5 V to - 5.5 V, 3 V to 11 V 輸出電流:100 mA 電源電流:1 mA 最大工作溫度:+ 70 C 封裝 / 箱體:SOIC-8 Narrow 封裝:Tube |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。