Description
The LTC®2862/LTC2863/LTC2864/LTC2865 are low power, 20Mbps or 250kbps RS485/RS422 transceivers operating on 3V to 5.5V supplies that feature ±60V overvoltage fault protection on the data transmission lines during all modes of operation, including power-down. Low EMI slew rate limited data transmission is available in a logic-selectable 250kbps mode in the LTC2865 and in 250kbps versions of the LTC2862-LTC2864. Enhanced ESD protection allows these parts to withstand ±15kV HBM on the transceiver interface pins without latchup or damage.
Extended ±25V input common mode range and full failsafe operation improve data communication reliability in electrically noisy environments and in the presence of large ground loop voltages.
Features
- Protected from Overvoltage Line Faults to ±60V
- 3V to 5.5V Supply Voltage
- 20Mbps or Low EMI 250kbps Data Rate
- ±15kV ESD Interface Pins, ±8kV All Other Pins
- Extended Common Mode Range: ±25V
- Guaranteed Failsafe Receiver Operation
- High Input Impedance Supports 256 Nodes
- 1.65V to 5.5V Logic Supply Pin (VL) for Flexible Digital Interface (LTC2865)
- H-Grade Option Available (–40°C to 125°C)
- Fully Balanced Differential Receiver Thresholds for Low Duty Cycle Distortion
- Current Limited Drivers and Thermal Shutdown
- Pin Compatible with LT1785 and LT1791
- Available in DFN and Leaded Packages
Applications
- Supervisory Control and Data Acquisition (SCADA)
- Industrial Control and Instrumentation Networks
- Automotive and Transportation Electronics
- Building Automation, Security Systems and HVAC
- Medical Equipment
- Lighting and Sound System Control
Linear Technology has a range of rugged, high voltage tolerant RS485/RS422 transceivers which it says can eliminate field failures without the need of costly external protection devices.
In practical RS485 systems, installation cross-wiring faults, ground voltage faults or lightning induced surge voltages can cause overvoltage conditions that exceed absolute maximum ratings of typical transceivers.
The LTC2862-2865 feature ±60V overvoltage fault protection on the data transmission lines, protecting bus pins during operation and power shutdown. Whether a circuit is transmitting, receiving, in standby or powered off, the LTC2862-2865 tolerate any voltage within ±60V without damage, increasing the robustness of any typical RS485 network.
The low power family supports fast 20Mbit/s and low-EMI slew-rate-limited 250kbit/s data rates, as well as half- and full-duplex versions.
The LTC2862-2865 family provides protection and reliability for a variety of RS485/RS422 applications, including industrial control, instrumentation networks and automotive electronics.
An extended ±25V input common-mode range and full failsafe operation improve data communications reliability in electrically noisy environments and in the presence of ground loop voltages. This extended common-mode range allows the LTC2862-2865 devices to transmit and receive under harsh conditions that would otherwise cause data errors and possible device damage.
Enhanced ESD protection allows these devices to withstand ±15kV (HBM and IEC-1000-4-2 air discharge) on the transceiver pins without latchup or damage; all other pins are protected to ±8kV HBM. Fully symmetric receiver thresholds allow the devices to maintain good duty cycle symmetry at low signal levels and boost receiver noise immunity.
For more read: Linear has transceiver that is reliable in the field
