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参数资料
| 型号： | SP3249ECY-L/TR |
| 厂商： | Exar Corporation |
| 文件页数： | 15/16页 |
| 文件大小： | 0K |
| 描述： | IC TXRX RS232 INTELLIGNT 24TSSOP |
| 产品变化通告： | Packaging Change 15/Jul/2010 |
| 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： | 24-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 24-TSSOP |
| 包装： | 带卷 (TR) |
8
Exar Corporation 48720 Kato Road, Fremont CA, 94538 510-668-7017 www.exar.com
SP3249E_100_013111
Charge Pump
The charge pump is an Exar–patented 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 symmetrical 5.5V
power supplies. The internal power supply
consists of a regulated dual charge pump that
provides output voltages 5.5V regardless of
the input voltage (V
CC) over the +3.0V to +5.5V
range. This is important to maintain compli-
ant RS-232 levels regardless of power supply
fluctuations.
The charge pump operates in a discontinuous
mode using an internal oscillator. If the output
voltages are less than a magnitude of 5.5V, the
charge pump is enabled. If the output voltages
exceed a magnitude of 5.5V, the charge pump
is disabled. This oscillator controls the four
phases of the voltage shifting. A description of
each phase follows.
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.
Figure 7. Loopback Test Circuit for RS-232 Driver
Data Transmission Rates
Figure 9. Loopback Test results at 250Kbps
(All Drivers Fully Loaded)
Figure 8. Loopback Test results at 120kbps
(All Drivers Fully Loaded)
SP3249E
TxIN
TxOUT
C1+
C1-
C2+
C2-
V+
V-
VCC
0.1F
+
C2
C5
C1
+
C3
C4
+
LOGIC
INPUTS
VCC
5k
RxIN
RxOUT
LOGIC
OUTPUTS
GND
1000pF
0.1F
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相关代理商/技术参数 |
参数描述 |
|---|---|
| SP3249EEA | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Intelligent +3.0V to +5.5V RS-232 Transceivers |
| SP3249EEY | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Intelligent +3.0V to +5.5V RS-232 Transceivers |
| SP3249EEY-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: |
| SP3249EEY-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: |
| SP3-2-50 | 制造商:RHOMBUS-IND 制造商全称:Rhombus Industries Inc. 功能描述:SP3 Series Mini-SIP Passive Delay Modules |
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