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参数资料
| 型号： | TC7660HCOAG |
| 元件分类： | 稳压器 |
| 英文描述： | SWITCHED CAPACITOR REGULATOR, 120 kHz SWITCHING FREQ-MAX, PDSO8 |
| 封装： | SOIC-8 |
| 文件页数： | 3/8页 |
| 文件大小： | 76K |
| 代理商： | TC7660HCOAG |
3
HIGH FREQUENCY 7660 DC-TO-DC
VOLTAGE CONVERTER
TC7660H
TC7660H-2 10/1/96
2001 Microchip Technology Inc.
DS21466A
Detailed Description
The TC7660H contains all the necessary circuitry to
implement a voltage inverter, with the exception of two
external capacitors, which may be inexpensive 1.0
F
non-polarized capacitors. Operation is best understood by
considering Figure 2, which shows an idealized voltage
inverter. Capacitor C1 is charged to a voltage, V+, for the half
cycle when switches S1 and S3 are closed. (Note: Switches
S2 and S4 are open during this half cycle.) During the second
half cycle of operation, switches S2 and S4 are closed, with
S1 and S3 open, thereby shifting capacitor C1 negatively by
V+ volts. Charge is then transferred from C1 to C2, such that
the voltage on C2 is exactly V+, assuming ideal switches and
no load on C2.
V+
GND
S3
S1
S2
S4
C2
VOUT
= – VIN
Figure 2. Idealized Charge Pump Inverter
Figure 1. TC7660H Test Circuit
1
2
3
4
8
7
6
5
TC7660H
+
V+
(+5V)
C1
1.0
F
+
C2
1.0
F
RL
IS
To improve low-voltage operation, the LV pin should be
connected to GND. For supply voltages greater than 3.5V,
the LV terminal must be left open to ensure latch-up-
proof operation and prevent device damage.
Theoretical Power Efficiency Considerations
In theory, a capacitative charge pump can approach
100% efficiency if certain conditions are met:
(1) The drive circuitry consumes minimal power.
(2) The output switches have extremely low ON
resistance and virtually no offset.
(3) The impedances of the pump and reservoir
capacitors are negligible at the pump frequency.
The TC7660H approaches these conditions for nega-
tive voltage multiplication if large values of C1 and C2 are
used. Energy is lost only in the transfer of charge
between capacitors if a change in voltage occurs. The
energy lost is defined by:
E = 1/2 C1 (V12 – V22)
V1 and V2 are the voltages on C1 during the pump and
transfer cycles. If the impedances of C1 and C2 are relatively
high at the pump frequency (refer to Figure 1), compared to
the value of RL, there will be a substantial difference in
voltages V1 and V2. Therefore, it is not only desirable to
make C2 as large as possible to eliminate output voltage
ripple, but also to employ a correspondingly large value for
C1 in order to achieve maximum efficiency of operation.
Do's and Don'ts
Do not exceed maximum supply voltages.
Do not connect LV terminal to GND for supply voltages
greater than 3.5V.
Do not short circuit the output to V+ supply for voltages
above 5.5V for extended periods; however, transient
conditions including start-up are okay.
When using polarized capacitors in the inverting mode,
the + terminal of C1 must be connected to pin 2 of the
TC7660H and the + terminal of C2 must be connected
to GND Pin 3.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| TC7660HCPA | 功能描述:电荷泵 High Frequency RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube |
| TC7660HCPA | 制造商:TELCOM SEMICONDUCTOR 功能描述:DC/DC VOLT CONVERTER 7660 DIP8 |
| TC7660HEOA | 功能描述:电荷泵 High Frequency RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube |
| TC7660HEOA713 | 功能描述:电荷泵 High Frequency RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube |
| TC7660HEPA | 功能描述:电荷泵 High Frequency RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube |
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