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参数资料
| 型号： | SP3223EUEA-L/TR |
| 厂商： | Exar Corporation |
| 文件页数： | 3/20页 |
| 文件大小： | 0K |
| 描述： | IC TXRX RS232 INTELLIGENT 20SSOP |
| 标准包装： | 1,500 |
| 类型： | 收发器 |
| 驱动器/接收器数： | 2/2 |
| 规程： | RS232 |
| 电源电压： | 3 V ~ 5.5 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 20-SSOP（0.209"，5.30mm 宽） |
| 供应商设备封装： | 20-SSOP |
| 包装： | 带卷 (TR) |
Exar Corporation 48720 Kato Road, Fremont CA, 94538 (50)668-707 www.exar.com
SP3223E/EB/EU_0_06272
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
and C2 are initially charged to VCC.
C
l
+
is then switched to GND and the charge
in C
–
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 C
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
produces –VCC in
the negative terminal of C
, 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
positivesideofcapacitorC
is switched to VCC
and the negative side is switched to GND, al-
lowingthechargepumpcycletobeginagain.
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.
The Exar charge pump is designed to
operate reliably with a range of low cost
capacitors. Either polarized or non polar-
ized capacitors may be used. If polarized
capacitors are used they should be oriented
as shown in the Typical Operating Circuit.
TheV+capacitormaybeconnectedtoeither
ground or Vcc (polarity reversed.)
The charge pump operates with 0.F
capacitors for 3.3V operation. For other
supply voltages, see table 4 for required
capacitor values. Do not use values smaller
than those listed. Increasing the capacitor
values (e.g., by doubling in value) reduces
ripple on the transmitter outputs and may
slightly reduce power consumption. C2, C3,
and C4 can be increased without changing
C’s value.
For best charge pump efficiency locate the
charge pump and bypass capacitors as
close as possible to the IC. Surface mount
capacitors are best for this purpose. Using
capacitors with lower equivalent series re-
sistance (ESR) and self-inductance, along
with minimizing parasitic PCB trace induc-
tance will optimize charge pump operation.
Designers are also advised to consider that
capacitor values may shift over time and
operating temperature.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SP3223EUEP | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High Speed Intelligent +3.0V to +5.5V RS-232 Transceivers |
| SP3223EUEY | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High Speed Intelligent +3.0V to +5.5V RS-232 Transceivers |
| SP3223EUEY/TR | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High Speed Intelligent +3.0V to +5.5V RS-232 Transceivers |
| SP3223EUEY-L | 功能描述:RS-232接口集成电路 HIGH SPD INTELLIGENT +3V-+5.5V RS-232 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: |
| SP3223EUEY-L/TR | 功能描述:RS-232接口集成电路 HIGH SPD INTELLIGENT +3V-+5.5V RS-232 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: |
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