3.3-V/5-V multiprotocol transceivers provide integrated switchable termination
December 09, 2010 // Paul Buckley
Linear Technology Corporation has introduced the LTC2870 and LTC2871 multiprotocol transceivers with switchable integrated termination for 3.3 V and 5 V systems. RS485 systems require a termination resistor on the ends of the communication bus to minimize signal reflections.
Both the LTC2870 and LTC2871 integrate pin-controlled termination resistors that allow for easy interface reconfiguration, eliminating external resistors and control relays. The termination resistors, when enabled, are automatically switched on or out to match the transceiver's protocol selection of RS232 or RS485. Both devices also feature high ESD protection: ±26 kV HBM (LTC2870) or ±16 kV HBM (LTC2871) on the transceiver bus pins, when powered off or operating.
The LTC2870 can be configured as two RS232 single-ended transceivers or one RS485 differential transceiver on shared I/O lines, whereas the LTC2871 offers independent control of two RS232 transceivers and one RS485 transceiver, each on dedicated I/O lines. Both devices reduce component count for multiprotocol networks and offer on-the-fly configurability.
The LTC2870 and LTC2871 are suitable for a wide variety of applications, including software-selectable multiprotocol interface ports, point-of-sale terminals, security cameras, cable repeaters and protocol translators.
An optional 1.7 V to 5.5 V logic supply enables convenient digital interfacing, and an integrated DC/DC boost converter eliminates the need for multiple supplies to drive RS232 levels. Drivers and receivers can be independently disabled, leaving them in a high impedance state, consuming only 9 µA in a low power shutdown mode. Aside from automatic termination selection, both devices provide half- and full-duplex RS485 switching and a logic loopback mode that steers the driver inputs to the receiver outputs for diagnostic self-test and debug.
Other protective measures include high ESD of ±4 kV or better on all pins, thermal shutdown protection and a full failsafe RS485 receiver for floating, shorted or terminated inputs that eliminates the need for external network biasing resistors and UART lockup.
The LTC2870 is available in 28-pin 4 mm x 5 mm QFN and TSSOP packages, and the LTC2871 is available in 38-pin 5 mm x 7 mm QFN and TSSOP packages. Both devices are available today in production quantities, priced starting at $5.00 each in 1,000 piece quantities.
More information about the LTC2870 and LTC2871 multiprotocol transceivers at www.linear.com/2870
Visit Linear Technology at www.linear.comAll news
Is there a future for the MOST bus?
October 01, 2014
In no other domain in the car, the technological evolution is advancing more rapidly than in the infotainment sector. Nevertheless, ...
Beyond programmability: full design observability at runtime
Nikola Tesla's lab could speak to future generations
Macronix rolls out European expansion plan
Intel leads non-iPad tablet processor market
Farnell element14 signs global agreement with RECOM Power
October 01, 2014
Farnell element14 has added RECOM Power, an innovative leader in the manufacture and distribution of power converters and ...
Could low-power 3D nanomagnetic logic replace transistors?
Oscilloscope engine plugs into portable Apple products
BMW joins forces with Baidu for automated driving
- Solutions for Millimeter Wave Wireless Backhaul
- Enter Linduino
- A Novel Approach to Industrial Rectifier Systems
- Putting FPGAs to Work in Software Radio Systems Handbook
InterviewIs there a future for the MOST bus?
In no other domain in the car, the technological evolution is advancing more rapidly than in the infotainment sector. Nevertheless, the MOST data networking technology seems to maintain its position as ...
Filter WizardCheck out the Filter Wizard Series of articles by Filter Guru Kendall Castor-Perry which provide invaluable practical Analog Design guidelines.
Linear video channel
READER OFFERRead more
This month, Oscium is giving away three of its iMSO-204L dual analogue iOS oscilloscopes, worth USD400 each. Designed with native Lightning compatibility, the iMSO-204L transforms the iPad, iPhone, and iPod touch into an ultra-portable, two-channel oscilloscope.
Since Apple changed its connector, Oscium has been working to bring native compatibility to its customers. The third generation...MORE INFO AND LAST MONTH' WINNERS...
December 15, 2011 | Texas instruments | 222901974
Unique Ser/Des technology supports encrypted video and audio content with full duplex bi-directional control channel over a single wire interface.