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參數(shù)資料
| 型號： | ICL7660CUA |
| 廠商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | Switched-Capacitor Voltage Converters |
| 中文描述： | SWITCHED CAPACITOR CONVERTER, 10 kHz SWITCHING FREQ-MAX, PDSO8 |
| 封裝： | MINIATURE, UMAX-8 |
| 文件頁數(shù)： | 9/12頁 |
| 文件大小： | 116K |
| 代理商： | ICL7660CUA |
The first term is the effective resistance from the
switched-capacitor circuit.
Conversion losses occur during the transfer of charge
between capacitors C1 and C2 when there is a voltage
difference between them. The power loss is:
Increasing Efficiency
Efficiency can be improved by lowering output voltage
ripple and output impedance. Both output voltage rip-
ple and output impedance can be reduced by using
large capacitors with low ESR.
The output voltage ripple can be calculated by noting
that the output current is supplied solely from capacitor
C2 during one-half of the charge-pump cycle.
Slowing the oscillator frequency reduces quiescent cur-
rent. The oscillator frequency can be reduced by con-
necting a capacitor to the OSC pin.
Reducing the oscillator frequency increases the ripple
voltage in the MAX1044/ICL7660. Compensate by
increasing the values of the bucket and reservoir
capacitors. For example, in a negative voltage converter,
the pump frequency is around 4kHz or 5kHz. With the
recommended 10μF bucket and reservoir capacitors,
the circuit consumes about 70μA of quiescent current
while providing 20mA of output current. Setting the
oscillator to 400Hz by connecting a 100pF capacitor to
OSC reduces the quiescent current to about 15μA.
Maintaining 20mA output current capability requires
increasing the bucket and reservoir capacitors to
100μF.
Note that lower capacitor values can be used for lower
output currents. For example, setting the oscillator to
40Hz by connecting a 1000pF capacitor to OSC pro-
vides the highest efficiency possible. Leaving the bucket
and reservoir capacitors at 100μF gives a maximum
I
of 2mA, a no-load quiescent current of 10μA, and
a power conversion efficiency of 98%.
General Prec autions
1) Connecting any input terminal to voltages greater
than V+ or less than ground may cause latchup. Do
not apply any input sources operating from external
supplies before device power-up.
2) Never exceed maximum supply voltage ratings.
3) Do not connect C1 and C2 with the wrong polarity.
4) Do not short V+ to ground for extended periods with
supply voltages above 5.5V present on other pins.
5) Ensure that V
(pin 5) does not go more positive
than GND (pin 3). Adding a diode in parallel with
C2, with the anode connected to V
OUT
and cathode
to LV, will prevent this condition.
________________Applic ation Circ uits
Negative V oltage Converter
Figure 8 shows a negative voltage converter, the most
popular application of the MAX1044/ICL7660. Only two
external capacitors are needed. A third power-supply
bypass capacitor is recommended (0.1μF to 10μF)
V
1
2 x f
x C2
2 x ESR
I
RIPPLE
OSC
C2
OUT
+
P
1
V
1
2C2 V
2V
x f
/ 2
CONV.LOSS
OUT
2
RIPPLE
2
OUT RIPPLE
OSC
)
=
+
2
M
S witc hed-Capac itor Voltage Converters
_______________________________________________________________________________________
9
MAX1044
ICL7660
4
3
C1
10μF
V
OUT
=
-(V+)
C
0.1μF
2
1
5
6
7
8
C2
10μF
V+
BOOST
LV
Figure 8. Negative Voltage Converter with BOOST and LV
Connections
MAX1044
ICL7660
4
3
V
OUT
= 2(V+) - 2V
D
2
1
5
6
7
8
C1
C2
V+
Figure 9. Voltage Doubler
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| ICL7660CUA+ | 功能描述:電荷泵 Switched-Capacitor Voltage Converter 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 |
| ICL7660CUA+T | 功能描述:電荷泵 Switched-Capacitor Voltage Converter 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 |
| ICL7660CUA-T | 功能描述:電荷泵 Switched-Capacitor Voltage Converter 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 |
| ICL7660EJA | 功能描述:電荷泵 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 |
| ICL7660EPA | 功能描述:電荷泵 Switched-Capacitor Voltage Converter 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 |
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