công cụ tìm kiếm bảng dữ liệu linh kiện điện tử
  Vietnamese  ▼
ALLDATASHEET.VN

X  

ML145406EP bảng dữ liệu(PDF) 5 Page - LANSDALE Semiconductor Inc.

tên linh kiện ML145406EP
Giải thích chi tiết về linh kiện  Driver/Receiver EIA 232?밇 and CCITT V.28
Download  10 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
nhà sản xuất  LANSDALE [LANSDALE Semiconductor Inc.]
Trang chủ  http://www.lansdale.com
Logo LANSDALE - LANSDALE Semiconductor Inc.

ML145406EP bảng dữ liệu(HTML) 5 Page - LANSDALE Semiconductor Inc.

  ML145406EP Datasheet HTML 1Page - LANSDALE Semiconductor Inc. ML145406EP Datasheet HTML 2Page - LANSDALE Semiconductor Inc. ML145406EP Datasheet HTML 3Page - LANSDALE Semiconductor Inc. ML145406EP Datasheet HTML 4Page - LANSDALE Semiconductor Inc. ML145406EP Datasheet HTML 5Page - LANSDALE Semiconductor Inc. ML145406EP Datasheet HTML 6Page - LANSDALE Semiconductor Inc. ML145406EP Datasheet HTML 7Page - LANSDALE Semiconductor Inc. ML145406EP Datasheet HTML 8Page - LANSDALE Semiconductor Inc. ML145406EP Datasheet HTML 9Page - LANSDALE Semiconductor Inc. Next Button
Zoom Inzoom in Zoom Outzoom out
 5 / 10 page
background image
www.lansdale.com
Page 5 of 10
Issue A
LANSDALE Semiconductor, Inc.
ML145406
The ML145406 has been designed to meet the electrical-
specifications of standards EIA 232–E and CCITT V.28. EIA
232–E defines the electrical and physical interface between
Data Communication Equipment (DCE) and DataTerminal
Equipment (DTE). A DCE is connected to a DTE using a cable
that typically carries up to 25 leads. These leads, referred to as
interchange circuits, allow the transfer of timing, data, control,
and test signals. Electrically this transfer requires level shifting
between the TTL/CMOS logic levels of the computer or
modem and the high voltage levels of EIA 232–E, which can
range from ±3 to ±25 V. The ML145406 provides the neces-
sary level shifting as well as meeting other aspects of the EIA
232–E specification.
DRIVERS
As defined by the specification, an EIA 232–E driver pres-
ents a voltage of between ±5 to ±15 V into a load of between 3
to 7 kΩ. A logic 1 at the driver input results in a voltage of
between –5 to – 15 V. A logic 0 results in a voltage between +
5 to + 15V. When operating VDD and VSS at ±7 to ±12 V, the
ML145406 meets this requirement. When operating at ±5 V,
the ML145406 drivers produce less than ±5 V at the output
(when terminated), which does not meet EIA 232–E specifica-
tion. However, the output voltages when using a ±5 V power
supply are high enough (around ±4 V) to permit proper recep-
tion by an EIA 232–E receiver, and can be used in applications
where strict compliance to EIA 232–E is not required.
Another requirement of the ML145406 drivers is that they
withstand a short to another driver in the EIA 232–E cable.
The worst–case condition that is permitted by EIA 232–E is a
±15V source that is current limited to 500 mA. The ML145406
drivers can withstand this condition momentarily. In most short
circuit conditions the source driver will have a series 300 Ω
output impedance needed to satisfy the EIA 232–E driver
requirements. This will reduce the short circuit current to
under 40 mA which is an acceptable level for the ML145406
to withstand.
Unlike some other drivers, the ML145406 drivers feature an
internally–limited output slew–rate that does not exceed 30 V
per µs.
RECEIVERS
The job of an EIA 232–E receiver is to level–shift voltages
in the range of – 25 to + 25 V down to TTL/CMOS logic lev-
els (0 to + 5 V). A voltage of between – 3 and – 25 V on Rx1
is defined as a mark and produces a logic 1 at DO1. A voltage
between + 3 and + 25 V is a space and produces a logic zero.
While receiving these signals, the Rx inputs must present a
resistance between 3 and 7 kΩ. Nominally, the input resistance
of the Rx1–Rx3 inputs is 5.4 kΩ.
The input threshold of the Rx1–Rx3 inputs is typically
biased at 1.8 V above ground (GND) with typically 800 mV of
hysteresis included to improve noise immunity. The 1.8 V bias
forces the appropriate DO pin to a logic 1 when its Rx input is
open or grounded as called for in the EIA 232–E specification.
Notice that TTL logic levels can be applied to the Rx inputs in
lieu of normal EIA 232–E signal levels. This might be helpful
in situations where access to the modem or computer through
the EIA 232–E connector is necessary with TTL devices.
However, it is important not to connect the EIA 232–E outputs
(Tx1–Tx3) to TTL inputs since TTL operates off + 5 V only,
and may be damaged by the high output voltage of the
ML145406.
The DO outputs are to be connected to a TTL or CMOS
input (such as an input to a modem chip). These outputs will
swing from VCC to ground, allowing the designer to operate
the DO and DI pins from digital power supply. The Tx and Rx
sections are independently powered by VDD andVSS so that
one may run logic at + 5 V and the EIA 232–E signals at ±12V.
POWER SUPPLY CONSIDERATIONS
Figure 4 shows a technique to guard against excessive device
current.
The diode D1 prevents excessive current from flowing
through an internal diode from the VCC pin to the VDD pin
when VDD < VCC by approximately 0.6 V. This high current
condition can exist for a short period of time during
powerup/down. Additionally, if the + 12 V supply is switched
off while the + 5 V is on and the off supply is a low impedance
to ground, the diode D1 will prevent current flow through the
internal diode.
The diode D2 is used as a voltage clamp, to prevent VSS
from drifting positive to VCC, in the event that power is
removed from VSS (Pin 12). If VSS power is removed, and the
impedance from the VSS pin to ground is greater than approxi-
mately 3 kΩ, this pin will be pulled to VCC by internal circuit-
ry causing excessive current in the VCC pin.
If by design, neither of the above conditions are allowed to
exist, then the diodes D1 and D2 are not required.
ESD PROTECTION
ESD protection on IC devices that have their pins accessible
to the outside world is essential. High static voltages applied to
the pins when someone touches them either directly or indi-
rectly can cause damage to gate oxides and transistor junctions
by coupling a portion of the energy from the I/O pin to the
power supply buses of the IC. This coupling will usually occur
through the internal ESD protection diodes. The key to protect-
ing the IC is to shunt as much of the energy to ground as pos-
sible before it enters the IC. Figure 4 shows a technique which
will clamp the ESD voltage at approximately ±15 V using the
MMVZ15VDLT1. Any residual voltage which appears on the
supply pins is shunted to ground through the capacitors
C1–C3. This scheme has provided protection to the interface
part up to ±10kV, using the human body model test.
Legacy Applications Information


Số phần tương tự - ML145406EP

nhà sản xuấttên linh kiệnbảng dữ liệuGiải thích chi tiết về linh kiện
logo
LANSDALE Semiconductor ...
ML145406EP LANSDALE-ML145406EP Datasheet
759Kb / 10P
   Driver/Receiver EIA 232-E and CCITT V.28 (Formerly RS-232-D)
More results

Mô tả tương tự - ML145406EP

nhà sản xuấttên linh kiệnbảng dữ liệuGiải thích chi tiết về linh kiện
logo
LANSDALE Semiconductor ...
ML145403 LANSDALE-ML145403_08 Datasheet
259Kb / 8P
   Drivers/Receivers RS 232/EIA??32?밇 and CCITT V.28
ML145406 LANSDALE-ML145406 Datasheet
759Kb / 10P
   Driver/Receiver EIA 232-E and CCITT V.28 (Formerly RS-232-D)
ML145407 LANSDALE-ML145407 Datasheet
679Kb / 8P
   5 Volt Only Driver/Receiver RS232 EIA-232-E and CCITT V.28
ML145403 LANSDALE-ML145403 Datasheet
916Kb / 8P
   Drivers/Receivers RS 232/EIA-232-E and CCITT V.28
logo
NXP Semiconductors
MC145406 PHILIPS-MC145406 Datasheet
90Kb / 5P
   EIA-232-D/V.28 driver/receiver
August 31, 1994
logo
LANSDALE Semiconductor ...
ML145583 LANSDALE-ML145583 Datasheet
527Kb / 7P
   3.3 Volt Only Driver/Receiver with an Integrated Standby Mode RS 232/EIA-232-E and CCITT V.28
logo
Integral Corp.
IN145406 INTEGRAL-IN145406 Datasheet
112Kb / 3P
   EIA-232-E / V.28 DRIVERS/RECEIVERS
logo
Texas Instruments
SN75LBC187 TI-SN75LBC187 Datasheet
126Kb / 8P
[Old version datasheet]   MULTICHANNEL EIA-232 DRIVER/RECEIVER WITH CHARGE PUMP
logo
National Semiconductor ...
DS14185 NSC-DS14185 Datasheet
173Kb / 8P
   EIA/TIA-232 3 Driver x 5 Receiver
DS14196 NSC-DS14196 Datasheet
131Kb / 7P
   EIA/TIA-232 5 Driver x 3 Receiver
More results


Html Pages

1 2 3 4 5 6 7 8 9 10


bảng dữ liệu tải về

Go To PDF Page


Link URL




Chính sách bảo mật
ALLDATASHEET.VN
Cho đến nay ALLDATASHEET có giúp ích cho doanh nghiệp của bạn hay không?  [ DONATE ] 

Alldatasheet là   |   Quảng cáo   |   Liên lạc với chúng tôi   |   Chính sách bảo mật   |   Trao đổi link   |   Tìm kiếm theo nhà sản xuất
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com