Friday, June 09, 2006
RS485 transceivers need no termination resistors
Half- and full-duplex RS485 transceivers feature switchable integrated termination.
Linear Technology has introduced the LTC2859 and LTC2861, half-duplex and full-duplex RS485 transceivers with switchable, integrated termination. Traditional RS485 networks require 120ohm termination resistors to be installed by the end user based on the physical layout of the twisted-pair wires and the placement of the nodes. As the bus is extended, the termination must be changed again by the end user.
Switching the integrated termination in the LTC2859/LTC2861 on or off under software control allows the proper nodes to be terminated without the end user's physical intervention.
In addition to the innovative termination capacity, the LTC2859/LTC2861 offer advanced transceiver features for industrial, medical and automotive applications.
A slew rate control pin allows datarates up to 20Mbit/s or a low-EMI mode at 250Kbit/s.
The bus pin protection exceeds +/-15kV for ESD strikes (human body model).
The receiver input impedance allows up to 256 nodes on a single bus.
These features provide more functionality than existing RS485 transceivers and the integrated termination combined with the tiny DFN package provide a smaller solution overall.
Specified over the commercial and industrial temperature ranges, the LTC2859 is offered in the 10-lead (3 x 3mm) DFN package and the LTC2861 is offered in the 12-lead (4 x 3mm) DFN and 16-lead SSOP packages.
Pricing begins at $1.55 each in 1000-piece quantities.
Linear Technology has introduced the LTC2859 and LTC2861, half-duplex and full-duplex RS485 transceivers with switchable, integrated termination. Traditional RS485 networks require 120ohm termination resistors to be installed by the end user based on the physical layout of the twisted-pair wires and the placement of the nodes. As the bus is extended, the termination must be changed again by the end user.
Switching the integrated termination in the LTC2859/LTC2861 on or off under software control allows the proper nodes to be terminated without the end user's physical intervention.
In addition to the innovative termination capacity, the LTC2859/LTC2861 offer advanced transceiver features for industrial, medical and automotive applications.
A slew rate control pin allows datarates up to 20Mbit/s or a low-EMI mode at 250Kbit/s.
The bus pin protection exceeds +/-15kV for ESD strikes (human body model).
The receiver input impedance allows up to 256 nodes on a single bus.
These features provide more functionality than existing RS485 transceivers and the integrated termination combined with the tiny DFN package provide a smaller solution overall.
Specified over the commercial and industrial temperature ranges, the LTC2859 is offered in the 10-lead (3 x 3mm) DFN package and the LTC2861 is offered in the 12-lead (4 x 3mm) DFN and 16-lead SSOP packages.
Pricing begins at $1.55 each in 1000-piece quantities.
# posted by Swathi @ 4:34 AM 
