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參數(shù)資料
| 型號： | ADM660AR |
| 廠商： | ANALOG DEVICES INC |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | CMOS Switched-Capacitor Voltage Converters |
| 中文描述： | SWITCHED CAPACITOR CONVERTER, 120 kHz SWITCHING FREQ-MAX, PDSO8 |
| 封裝： | MS-012AA, SOIC-8 |
| 文件頁數(shù)： | 8/8頁 |
| 文件大小： | 111K |
| 代理商： | ADM660AR |
ADM660/ADM8660
REV. A
–8–
output current levels. T he ADM660/ADM8660 is tested using
low ESR, 10
μ
F, capacitors for both C1 and C2. Smaller values
of C1 increase the output resistance, while increasing C1 will re-
duce the output resistance. T he output resistance is also de-
pendent on the internal switches on resistance as well as the
capacitors ESR so the effect of increasing C1 becomes negligible
past a certain point.
Figure 23 shows how the output resistance varies with oscillator
frequency for three different capacitor values. At low oscillator
frequencies, the output impedance is dominated by the 1/f
C
term. T his explains why the output impedance is higher for
smaller capacitance values. At high oscillator frequencies, the
1/f
C
term becomes insignificant and the output impedance is
dominated by the internal switches on resistance. From an out-
put impedance viewpoint, therefore, there is no benefit to be
gained from using excessively large capacitors.
OSCILLATOR FREQUENCY – kHz
500
0
300
100
400
200
0.1
100
1
10
C1 = C2 = 2.2μF
C1 = C2 = 10μF
O
C1 = C2 = 1μF
Figure 23. Output Impedance vs. Oscillator Frequency
Capacitor C2
T he output capacitor size C2 affects the output ripple. Increas-
ing the capacitor size reduces the peak-peak ripple. T he ESR
affects both the output impedance and the output ripple.
Reducing the ESR reduces the output impedance and ripple.
For convenience it is recommended that both C1 and C2 be the
same value.
T able III. Capacitor Selection
Charge-Pump
Frequency
Capacitor
C1, C2
25 kHz
120 kHz
10
μ
F
2.2
μ
F
Power E fficiency and Oscillator Frequency T radeoff
While higher switching frequencies allow smaller capacitors to
be used for equivalent performance, or improved performance
with the same capacitors, there is a tradeoff to be considered. As
the oscillator frequency is increased, the quiescent current in-
creases. T his happens as a result of a finite charge being lost at
each switching cycle. T he charge loss per unit cycle at very high
frequencies can be significant, thereby reducing the power effi-
ciency. Since the power efficiency is also degraded at low oscil-
lator frequencies, due to an increase in output impedance, this
means that there is an optimum frequency band for maximum
power transfer. Please refer to the T ypical Performance Charac-
teristics section.
C
P
Bypass Capacitor
T he ac impedance of the ADM660/ADM8660 may be reduced
by using a bypass capacitor on the input supply. T his capacitor
should be connected between the input supply and GND. It
will provide instantaneous current surges as required. Suitable
capacitors of 0.1
μ
F or greater may be used.
OUT LINE DIME NSIONS
Dimensions shown in inches and (mm).
8-Lead Plastic DIP
(N-8)
8
1
4
5
0.430 (10.92)
0.348 (8.84)
0.280 (7.11)
0.240 (6.10)
PIN 1
SEATING
PLANE
0.022 (0.558)
0.014 (0.356)
0.060 (1.52)
0.015 (0.38)
0.210 (5.33)
MAX
0.130
(3.30)
MIN
0.070 (1.77)
0.045 (1.15)
0.100
(2.54)
BSC
0.160 (4.06)
0.115 (2.93)
0.325 (8.25)
0.300 (7.62)
0.015 (0.381)
0.008 (0.204)
0.195 (4.95)
0.115 (2.93)
8-Lead Narrow-Body SOIC
(SO-8)
0.1968 (5.00)
0.1890 (4.80)
8
5
4
1
0.2440 (6.20)
0.2284 (5.80)
PIN 1
0.1574 (4.00)
0.1497 (3.80)
0.0688 (1.75)
0.0532 (1.35)
SEATING
PLANE
0.0098 (0.25)
0.0040 (0.10)
0.0192 (0.49)
0.0138 (0.35)
0.0500
(1.27)
BSC
0.0098 (0.25)
0.0075 (0.19)
0.0500 (1.27)
0.0160 (0.41)
8
°
0
°
0.0196 (0.50)
°
16-Lead T SSOP
(RU-16)
16
9
8
1
0.201 (5.10)
0.193 (4.90)
0
0
0
0
PIN 1
SEATING
PLANE
0.006 (0.15)
0.002 (0.05)
0.0118 (0.30)
0.0075 (0.19)
0.0256
(0.65)
BSC
0.0433
(1.10)
MAX
0.0079 (0.20)
0.0035 (0.090)
0.028 (0.70)
0.020 (0.50)
8
°
0
°
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| ADM660AR-REEL | 制造商:Rochester Electronics LLC 功能描述:CHARGE PUMPED INVERTER I.C. - Tape and Reel 制造商:Analog Devices 功能描述:IC,DC/DC CONVERTER,CMOS,SOP,8PIN |
| ADM660AR-REEL7 | 制造商:Analog Devices 功能描述:Charge Pump INV/STPUP -1.5V to -7V/5V to 14V 100mA 8-Pin SOIC N T/R |
| ADM660ARU | 制造商:Analog Devices 功能描述:Charge Pump INV/STPUP -1.5V to -7V/5V to 14V 100mA 16-Pin TSSOP 制造商:Rochester Electronics LLC 功能描述:CHARGE PUMPED INVERTER I.C. - Bulk |
| ADM660ARU-REEL | 制造商:Analog Devices 功能描述:Charge Pump INV/STPUP -1.5V to -7V/5V to 14V 100mA 16-Pin TSSOP T/R 制造商:Rochester Electronics LLC 功能描述:CHARGE PUMPED INVERTER I.C. - Tape and Reel |
| ADM660ARU-REEL7 | 制造商:Analog Devices 功能描述:Charge Pump INV/STPUP -1.5V to -7V/5V to 14V 100mA 16-Pin TSSOP T/R 制造商:Rochester Electronics LLC 功能描述:CHARGE PUMPED INVERTER I.C. - Tape and Reel |
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