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参数资料
| 型号： | SP3249ECY-L/TR |
| 厂商： | Exar Corporation |
| 文件页数： | 14/16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) |
Exar Corporation 48720 Kato Road, Fremont CA, 94538 510-668-7017 www.exar.com
SP3249E_100_013111
7
DESCRIPTION
The SP3249E device meets the EIA/TIA-232
and ITU-T V.28/V.24 communication protocols
and can be implemented in battery-powered,
portable, or hand-held applications such as
notebook or palmtop computers. The SP3249E
devices feature Exar's proprietary and patented
(U.S.-- 5,306,954) on-board charge pump cir-
cuitrythatgenerates±5.5VRS-232voltagelevels
from a single +3.0V to +5.5V power supply. The
SP3249E devices can guarantee a data rate of
250kbps fully loaded.
TheSP3249Eisa5-driver/3-receiverdevice,ideal
for portable or hand-held applications.
THEORY OF OPERATION
The SP3249E device is made up of three basic
circuit blocks:
1. Drivers
2. Receivers
3. The Exar proprietary charge pump
Drivers
The drivers are inverting level transmitters that
convert TTL or CMOS logic levels to 5.0V EIA/
TIA-232 levels with an inverted sense relative
to the input logic levels. Typically, the RS-232
output voltage swing is +5.4V with no load and
+5V minimum fully loaded. The driver outputs are
protected against infinite short-circuits to ground
without degradation in reliability. These drivers
comply with the EIA-TIA-232-F and all previous
RS-232 versions.
The drivers can guarantee a data rate of 250kbps
fully loaded with 3k in parallel with 1000pF,
ensuring compatibility with PC-to-PC communi-
cation software. All unused drivers inputs should
be connected to GND or V
CC.
The slew rate of the driver output is internally
limited to a maximum of 30V/s in order to meet
theEIAstandards(EIARS-232D2.1.7,Paragraph
5). The transition of the loaded output from HIGH
toLOWalsomeetsthemonotonicityrequirements
of the standard.
Figure 7 shows a loopback test circuit used to
test the RS-232 drivers. Figure 8 shows the test
results of the loopback circuit with all five drivers
active at 120kbps with typical RS-232 loads in
parallel with 1000pF capacitors. Figure 9 shows
the test results where one driver was active
at 250kbps and all five drivers loaded with an
RS-232 receiver in parallel with a 1000pF ca-
pacitor. A solid RS-232 data transmission rate
of 120kbps provides compatibility with many
designs in personal computer peripherals and
LAN applications.
Receivers
The receivers convert +5.0V EIA/TIA-232
levels to TTL or CMOS logic output levels.
Since receiver input is usually from a transmis-
sion line where long cable lengths and system
interference can degrade the signal, the inputs
have a typical hysteresis margin of 300mV. This
ensures that the receiver is virtually immune to
noisy transmission lines. Should an input be left
unconnected, an internal 5k pulldown resistor
to ground will commit the output of the receiver
to a HIGH state.
Figure 6. Interface Circuitry Controlled by
Microprocessor Supervisory Circuit
SP3249E
24
21
3
1
23
4
22
GND
C1+
C1-
C2+
C2-
V+
V-
VCC
0.1F
+
C2
C5
C1
+
C3
C4
+
VCC
2
5k
20
19
18
17
16
14
5
6
7
8
9
11
RS-232
OUTPUTS
RS-232
INPUTS
T1IN
R1OUT
R1IN
T2OUT
T2IN
T3IN
T3OUT
T1OUT
R2IN
R3IN
R2OUT
R3OUT
UART
or
Serial C
TxD
RTS
DTR
RxD
CTS
DSR
DCD
RI
15
13
10
12
T4OUT
T4IN
T5IN
T5OUT
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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