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參數(shù)資料
| 型號： | SP207EHEA |
| 英文描述： | High Speed 5V High Performance RS232 Transceivers |
| 中文描述： | 高速5V的高性能RS232收發(fā)器 |
| 文件頁數(shù)： | 5/16頁 |
| 文件大?。?/td> | 204K |
| 代理商： | SP207EHEA |
5
SP207EHDS/08
SP207EH Series High Performance Transceivers
Copyright 2000 Sipex Corporation
FEATURES
As in the original RS-232 multi-channel
products, the
SP207EH
Series
high speed
multi-channel RS-232 line transceivers provide
a variety of configurations to fit most designs,
especially high speed applications where +12V
is not available. The
SP207EH Series
is a
superior high speed drop-in replacement to our
previous versions as well as popular industry
standards.
All devices in this series feature low-power
CMOS construction and
Sipex's
proprietary
on-board charge pump circuitry to generate the
+10V RS-232 voltage levels. The ability to
use 0.1
μ
F charge pump capacitors saves
board space and reduces production costs.
The devices in this series provide different
driver/receiver combinations to match any
application requirement.
The
SP211EH
and
SP213EH
models feature a
low–power shutdown mode, which reduces
power supply drain to 1
μ
A. The
SP213EH
includes a Wake-Up function which keeps two
receivers active in the shutdown mode, unless
disabled by the EN pin.
The family is available in 28–pin SO (wide) and
SSOP (shrink) small outline packages. Devices
can be specified for commercial (0
°
C to +70
°
C)
and industrial/extended (–40
°
C to +85
°
C) oper-
ating temperatures.
THEORY OF OPERATION
The
SP207EH Series
devices are made up of
three basic circuit blocks — 1) transmitter/
driver, 2) receiver and 3) the
SIPEX
–propri-
etary charge pump. Each model within the
Series incorporates variations of these circuits
to achieve the desired configuration and
performance.
Charge–Pump
The charge pump is a
Sipex
–patented design
(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 10V power supplies.
Figure 3a
shows the waveform found on the
positive side of capacitor C
, and
Figure 3b
shows
the negative side of capacitor C
. There is a
free–running oscillator that controls the four
phases of the voltage shifting. A description of
each phase follows.
Phase 1
— V
charge storage —During this phase of the
clock cycle, the positive side of capacitors C
1
and C
are initially charged to +5V. C
switched to ground and the charge in C
transferred to C
+5V, the voltage potential across capacitor C
2
is
now 10V.
+
is then
–
is
–
. Since C
+
is connected to
Phase 2
— V
transfer — Phase two of the clock
connects the negative terminal of C
to the V
SS
storage capacitor and the positive terminal of C
2
to ground, and transfers the generated –l0V to
C
3
. Simultaneously, the positive side of capacitor
C
is switched to +5V and the negative side is
connected to ground.
Phase 3
— V
charge storage — The third phase of the
clock is identical to the first phase — the charge
transferred in C
produces –5V in the negative
terminal of C
, which is applied to the negative
side of capacitor C
. Since C
voltage potential across C
2
is l0V.
+
is at +5V, the
V
CC
= +5V
–5V
–5V
+5V
V
SS
Storage Capacitor
V
DD
Storage Capacitor
C
1
C
2
C
3
C
4
+
+
+
+
–
–
–
–
Figure 1. Charge Pump — Phase 1
相關PDF資料 |
PDF描述 |
|---|---|
| SP207EHEP | High Speed 5V High Performance RS232 Transceivers |
| SP207EHET | High Speed 5V High Performance RS232 Transceivers |
| SP207B | 5V High-Speed RS-232 Transceivers with 0.1uF Capacitors |
| SP207BCA | 5V High-Speed RS-232 Transceivers with 0.1uF Capacitors |
| SP207BCT | 5V High-Speed RS-232 Transceivers with 0.1uF Capacitors |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| SP207EHEA-L | 制造商:Rochester Electronics LLC 功能描述: 制造商:Exar Corporation 功能描述: |
| SP207EHEA-L/TR | 制造商:Rochester Electronics LLC 功能描述: 制造商:Exar Corporation 功能描述: |
| SP207EHEP | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:High Speed +5V High Performance RS232 Transceivers |
| SP207EHET | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:High Speed +5V High Performance RS232 Transceivers |
| SP207EP | 制造商:SIPEX 制造商全稱:Sipex Corporation 功能描述:+5V High-Speed RS-232 Transceivers with 0.1mF Capacitors |
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