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参数资料
| 型号： | SP3220EUCY-L/TR |
| 厂商： | Exar Corporation |
| 文件页数： | 3/21页 |
| 文件大小： | 0K |
| 描述： | IC DVR/RCVR RS232 ESD 16TSSOP |
| 标准包装： | 2,500 |
| 类型： | 收发器 |
| 驱动器/接收器数： | 1/1 |
| 规程： | RS232 |
| 电源电压： | 3 V ~ 5.5 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 16-TSSOP |
| 包装： | 带卷 (TR) |
Exar Corporation 48720 Kato Road, Fremont CA, 94538 510-668-7017 www.exar.com
SP3220E_EB_EU_101_060311
11
Charge Pump
The charge pump is an Exar-patended
design (U.S. 5,306,954) and uses a unique
approach compared to older less-efficient
designs. The charge pump still requires four
external capacitors, but uses a four-phase
voltage shifting technique to attain sym-
metrical 5.5V power supplies. The internal
power supply consists of a regulated dual
charge pump that provides output voltages
of +/-5.5V regardless of the input voltage
(Vcc) over the +3.0V to +5.5V range.
In most circumstances, decoupling the
power supply can be achieved adequately
using a 0.1F bypass capacitor at C5 (refer
to figures 6 and 7). In applications that are
sensitive to power-supply noise, decouple
Vcc to ground with a capacitor of the same
value as charge-pump capacitor C1. Physi-
cally connect bypass capcitors as close to
the IC as possible.
The charge pump operates in a discontinu-
ous mode using an internal oscillator. If the
output voltages are less than a magnitude
of 5.5V, the charge pump is enabled. If the
outputvoltages exceedamagnitudeof5.5V,
the charge pump is disabled. This oscillator
controls the four phases of the voltage shift-
ing. A description of each phase follows.
Phase 1
— V
SS charge storage — During this phase
of the clock cycle, the positive side of capaci-
tors C
1 and C2 are initially charged to VCC.
C
l
+
is then switched to GND and the charge
in C
1
–
is transferred to C
2
–
. Since C
2
+
is con-
nected to V
CC, the voltage potential across
capacitor C
2 is now 2 times VCC.
Phase 2
— V
SS transfer — Phase two of the clock
connectsthenegativeterminalofC
2 to the VSS
storagecapacitorandthepositiveterminalof
C
2 to GND. This transfers a negative gener-
ated voltage to C
3. This generated voltage is
regulated to a minimum voltage of -5.5V.
Simultaneous with the transfer of the volt-
age to C
3, the positive side of capacitor C1
is switched to V
CC and the negative side is
connected to GND.
Phase 3
— V
DD charge storage — The third phase of
the clock is identical to the first phase — the
charge transferred in C
1 produces –VCC in
the negative terminal of C
1, which is applied
to the negative side of capacitor C
2. Since
C
2
+
is at V
CC, the voltage potential across C2
is 2 times V
CC.
Phase 4
— V
DD transfer — The fourth phase of
the clock connects the negative terminal
of C
2 to GND, and transfers this positive
generated voltage across C
2 to C4, the
V
DD storage capacitor.
This voltage is
regulated to +5.5V. At this voltage, the in-
ternal oscillator is disabled. Simultaneous
with the transfer of the voltage to C
4, the
positive side of capacitor C
1 is switched
to V
CC and
the
negative side is con-
nected to GND, allowing the charge
pump cycle to begin again. The charge
pump cycle will continue as long as the
operational conditions for the internal
oscillator are present.
Since both V+ and V– are separately gener-
ated from V
CC, in a no–load condition V
+
and V– will be symmetrical. Older charge
pump approaches that generate V– from
V+ will show a decrease in the magnitude
of V– compared to V+ due to the inherent
inefficiencies in the design.
DESCRIPTION
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SP3220EUEA | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High Speed +3.0V to +5.5V RS-232 Driver/Receiver Pair |
| SP3220EUEA-L | 功能描述:RS-232接口集成电路 RS232 1drvr/1rcvr -40C to 85C RoHS:否 制造商:Exar 数据速率:52 Mbps 工作电源电压:5 V 电源电流:300 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:LQFP-100 封装: |
| SP3220EUEA-L/TR | 功能描述:RS-232接口集成电路 RS232 1drvr/1rcvr -40C to 85C RoHS:否 制造商:Exar 数据速率:52 Mbps 工作电源电压:5 V 电源电流:300 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:LQFP-100 封装: |
| SP3220EUET | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High Speed +3.0V to +5.5V RS-232 Driver/Receiver Pair |
| SP3220EUET-L | 制造商:EXAR 制造商全称:EXAR 功能描述:3.0V to 5.5V RS-232 Driver/Receiver Pair |
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