Achieved 20Mbps speed

December 23, 2011 – Linear Technology Korea (CEO Hong Sa-kwak) announced the development of a highly robust and high-voltage-resistant RS485/RS422 transceiver (Product Name: LTC2862-2865) capable of preventing field failures without the need for expensive external protection devices. In actual RS485 systems, installation cross-wiring failures, ground voltage errors, or lightning-induced surge voltages can cause overvoltage conditions exceeding the absolute maximum ratings of standard transceivers. The LTC2862-2865 features ±60V overvoltage fault protection on data transmission lines, protecting bus pins during device operation and power interruption. Regardless of the circuit state—whether transmitting, receiving standby, or power off—the LTC2862-2865 can withstand any voltage within the ±60V range without damaging the device, thereby enhancing the robustness of all general RS485 networks. This low-power product family supports fast 20Mbps and low EMI slew-rate-limited 250kbps data rates, as well as half/full-duplex versions.
The LTC2862-2865 product family provides excellent protection and reliability features for a wide range of RS485/RS422 applications, including industrial control, instrumentation networks, and automotive electronics. The extended input common-mode range of up to ±25V and full fail-safe operation enhance data communication reliability when used in electrically noisy environments and in the presence of ground loop voltage. With the expanded common-mode range, LTC2862-2865 devices are capable of transmitting and receiving even under demanding conditions that could cause data errors and device damage. Additionally, ESD protection has been further improved, allowing these devices to withstand ±15kV (HBM and IEC-1000-4-2 air discharge) at the transceiver pins without latch-up or damage. All other pins are protected by ±8kV HBM. A complete symmetric receiver threshold enables these devices to maintain good duty cycle symmetry even at low signal levels and enhance receiver noise immunity.
The LTC2862-2865 product family is available in commercial, industrial, and automotive temperature grades and in DFN and SO packages with industrial standard pinouts. The product is priced at $2.35 per unit for the 20Mbps half-duplex version in a 1,000-unit quantity.
These devices provide a 250-pin compatible upgrade path from Linear's 250kbps ±60V fault-protected transceivers, the half-duplex LT1785 and full-duplex LT1791. For more information, refer to www.linear.com/product/LTC2862 .

Photo caption: RS485 transceiver with ±60V fault protection and a ±25V common mode range

Product Features: LTC2862-65

• Protection against overvoltage line faults up to ±60V
• Supply voltage of 3V ~ 5.5V
• 20Mbps or low EMI 250kbps data rates
• ESD interface pin ±15kV, all other pins ±8kV
• Expanded common mode range: ±25V
• Fail-safe receiver operation guaranteed
• Supports up to 256 nodes
• Individual 1.65V ~ 5.5V logic supply pins (LTC2865)
• Temperature range: -40°C to 125°C
• Industry standard pinout