LT1791AHS#TRPBF Linear Technology, LT1791AHS#TRPBF Datasheet

IC TXRX RS485/RS422 60V 14-SOIC

LT1791AHS#TRPBF

Manufacturer Part Number
LT1791AHS#TRPBF
Description
IC TXRX RS485/RS422 60V 14-SOIC
Manufacturer
Linear Technology
Type
Transceiverr
Datasheet

Specifications of LT1791AHS#TRPBF

Number Of Drivers/receivers
1/1
Protocol
RS422, RS485
Voltage - Supply
4.75 V ~ 5.25 V
Mounting Type
Surface Mount
Package / Case
14-SOIC (3.9mm Width), 14-SOL
Lead Free Status / RoHS Status
Lead free / RoHS Compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LT1791AHS#TRPBFLT1791AHS#PBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
Company:
Part Number:
LT1791AHS#TRPBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
APPLICATIONS
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
FEATURES
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Protected from Overvoltage Line Faults to ±60V
Pin Compatible with LTC485 and LTC491
High Input Impedance Supports Up to 128 Nodes
No Damage or Latchup to ESD
Controlled Slew Rates for EMI Emissions Control
Guaranteed High Receiver Output State for Floating,
Shorted or Inactive Inputs
Outputs Assume a High Impedance When Off or
Powered Down
Drives Low Cost, Low Impedance Cables
Short-Circuit Protection on All Outputs
Thermal Shutdown Protection
Guaranteed Operation to 125°C
Industrial Control Data Networks
CAN Bus Applications
HVAC Controls
IEC-1000-4-2 Level 4: ±15kV Air Discharge
IEC-1000-4-2 Level 2: ±4kV Contact Discharge
RO1
RO2
RE1
DE1
RE2
DE2
DI1
DI2
TX
TX
LT1785
LT1785
RX
RX
V
V
GND1
GND2
CC1
CC2
R
R
TERM
TERM
178591 TA01
DESCRIPTION
The LT
ential bus transceivers for RS485 and RS422 applications
which feature on-chip protection from overvoltage faults
on the data transmission lines. Receiver input and driver
output pins can withstand voltage faults up to ±60V with
respect to ground with no damage to the device. Faults
may occur while the transceiver is active, shut down or
powered off.
Data rates to 250kbaud on networks of up to 128 nodes
are supported. Controlled slew rates on the driver out-
putscontrol EMI emissions and improve data transmis-
sion integrity on improperly terminated lines. Drivers are
specifi ed to operate with inexpensive cables as low as
72Ω characteristic impedance.
The LT1785A/LT1791A devices have “fail-safe” receiver
inputs to guarantee a receiver output high for shorted, open
or inactive data lines. On-chip ESD protection eliminates
need for external protection devices.
The LT1785/LT1785A are available in 8-lead DIP and SO
packages and the LT1791/LT1791A in 14-lead DIP and
SO packages.
RS485/RS422 Transceivers
®
1785/LT1791 are half-duplex and full-duplex differ-
Y-Z
RO
DI
Normal Operation Waveforms at 250kBaud
60V Fault Protected
LT1785/LT1785A/
LT1791/LT1791A
178591 TA02
178591fc
1

Related parts for LT1791AHS#TRPBF

LT1791AHS#TRPBF Summary of contents

Page 1

... Thermal Shutdown Protection n Guaranteed Operation to 125°C APPLICATIONS n Industrial Control Data Networks n CAN Bus Applications n HVAC Controls L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION V CC1 RO1 RX RE1 LT1785 R ...

Page 2

LT1785/LT1785A/ LT1791/LT1791A ABSOLUTE MAXIMUM RATINGS Supply Voltage (V ) ................................................18V CC Receiver Enable Input Voltage ...................... –0. Driver Enable Input Voltage .......................... –0. Driver Input Voltage ................................... –0.3V to 18V Receiver Input Voltage ................................ –60V to ...

Page 3

... LT1791IN#TRPBF LT1791IS#PBF LT1791IS#TRPBF LT1791ACN#PBF LT1791ACN#TRPBF LT1791ACS#PBF LT1791ACS#TRPBF LT1791AIN#PBF LT1791AIN#TRPBF LT1791AIS#PBF LT1791AIS#TRPBF LT1791HN#PBF LT1791HN#TRPBF LT1791HS#PBF LT1791HS#TRPBF LT1791AHN#PBF LT1791AHN#TRPBF LT1791AHS#PBF LT1791AHS#TRPBF LEAD BASED FINISH TAPE AND REEL LT1785CN8 LT1785CN8#TR LT1785CS8 LT1785CS8#TR LT1785IN8 LT1785IN8#TR LT1785IS8 LT1785IS8#TR LT1785ACN8 LT1785ACN8#TR LT1785ACS8 LT1785ACS8#TR LT1785AIN8 LT1785AIN8#TR LT1785AIS8 LT1785AIS8#TR ...

Page 4

LT1785/LT1785A/ LT1791/LT1791A DC ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER V Differential Driver Output Voltage (Unloaded) OD1 V Differential Driver Output Voltage (With Load) OD2 V Change in Magnitude of Driver Differential Output OD Voltage ...

Page 5

SWITCHING CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER t Driver Input to Output PLH t Driver Input to Output PHL t Driver Output to Output SKEW Driver Rise or Fall Time r f ...

Page 6

LT1785/LT1785A/ LT1791/LT1791A TYPICAL PERFORMANCE CHARACTERISTICS Driver Differential Output Voltage vs Load Resistance 25° 100 LOAD RESISTANCE (Ω) 178591 G01 Driver Propagation Delay vs Temperature 1000 900 800 LH 700 600 HL ...

Page 7

PIN FUNCTIONS RO: Receiver Output. TTL level logic output. If the receiver is active (RE pin low high if receiver input A ≥ 200mV ≤ 200mV, then RO will be low. RO ...

Page 8

LT1785/LT1785A/ LT1791/LT1791A TEST CIRCUITS Figure 1. Driver DC Test Load DIFF Figure 3. Driver/Receiver Timing Test Circuit FUNCTION TABLES LT1785 Transmitting INPUTS RE DE ...

Page 9

SWITCHING TIME WAVEFORMS 1 – OD2 A – B ...

Page 10

LT1785/LT1785A/ LT1791/LT1791A APPLICATIONS INFORMATION Overvoltage Protection The LT1785/LT1791 RS485/RS422 transceivers answer an applications need for overvoltage fault tolerance on data networks. Industrial installations may encounter common mode voltages between nodes far greater than the –7V to 12V range specifi ed ...

Page 11

APPLICATIONS INFORMATION Slew Limiting for EMI Emissions Control The LT1785/LT1791 feature controlled driver output slew rates to control high frequency EMI emissions from equip- ment and data cables. The slew limiting limits data rate operation to 250kbaud. Slew limiting also ...

Page 12

LT1785/LT1785A/ LT1791/LT1791A PACKAGE DESCRIPTION .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 ( ) +0.889 8.255 –0.381 NOTE: 1. DIMENSIONS ARE MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH ...

Page 13

PACKAGE DESCRIPTION .050 BSC .245 MIN .030 ±.005 TYP RECOMMENDED SOLDER PAD LAYOUT .010 – .020 (0.254 – 0.508) .008 – .010 (0.203 – 0.254) NOTE: 1. DIMENSIONS IN 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE ...

Page 14

LT1785/LT1785A/ LT1791/LT1791A PACKAGE DESCRIPTION .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) +.035 .325 –.015 ( ) +0.889 8.255 –0.381 NOTE: INCHES 1. DIMENSIONS ARE MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD ...

Page 15

... MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...

Page 16

... Controlled Driver Slew Rate 10Mbaud Operation Up to 256 Transceivers on the Bus Channel-to-Channel Skew 400ps (Typ) 2500V Isolation in Surface Mount Package RMS Propagation Delay Skew 500ps (Typ) Propagation Delay Skew 500ps (Typ) LT 0409 REV C • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 1998 178591fc ...

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