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参数资料
| 型号： | SP3239ECA-L/TR |
| 厂商： | Exar Corporation |
| 文件页数： | 16/16页 |
| 文件大小： | 0K |
| 描述： | IC TXRX RS232 INTELLIGENT 28SSOP |
| 标准包装： | 1,500 |
| 类型： | 收发器 |
| 驱动器/接收器数： | 5/3 |
| 规程： | RS232 |
| 电源电压： | 3 V ~ 5.5 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-SSOP（0.209"，5.30mm 宽） |
| 供应商设备封装： | 28-SSOP |
| 包装： | 带卷 (TR) |
Exar Corporation 48720 Kato Road, Fremont CA, 94538 510-668-7017 www.exar.com
SP3239E_100_020111
9
Phase 1
— V
SS charge storage — During this phase of the
clock cycle, the positive side of capacitors C
1 and
C
2 are initially charged to VCC. Cl
+
is then switched
to GND and the charge in C
1
–
is transferred to C
2
–
.
SinceC
2
+
isconnectedtoV
CC, the voltage potential
across capacitor C
2 is now 2 times VCC.
Phase 2
— V
SS transfer — Phase two of the clock
connects the negative terminal of C
2 to the VSS
storage capacitor and the positive terminal of
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.
SimultaneouswiththetransferofthevoltagetoC
3,
the positive side of capacitor C
1 is switched to VCC
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 C2
+
is at V
CC, the volt-
age potential across C
2 is 2 times VCC.
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 VDD storage capacitor. This
voltage is regulated to +5.5V. At this voltage,
the internal oscillator is disabled. Simultane-
ous with the transfer of the voltage to C
4, the
positive side of capacitor C
1 is switched to VCC
and the negative side is connected to GND, al-
lowing 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 generated
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 clock rate for the charge pump typically
operates at 500kHz. The external capacitors
can be as low as 0.1F with a 16V breakdown
voltage rating.
Figure 10. Charge Pump Waveform
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SP3239ECY-L | 制造商:Rochester Electronics LLC 功能描述: 制造商:Exar Corporation 功能描述: |
| SP3239ECY-L/TR | 制造商:Rochester Electronics LLC 功能描述: 制造商:Exar Corporation 功能描述: |
| SP3239EEA-L | 功能描述:RS-232接口集成电路 Intel. +3V to +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: |
| SP3239EEA-L/TR | 功能描述:RS-232接口集成电路 Intel. +3V to +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: |
| SP3239EEY-L | 制造商:Rochester Electronics LLC 功能描述: 制造商:Exar Corporation 功能描述: |
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