1 Features

1• Drop-In Improved Replacement for the

PCA82C250 and PCA82C251

• Bus-Fault Protection of ±36 V

• Meets or Exceeds ISO 11898

• Signaling Rates(1) up to 1 Mbps

• High Input Impedance Allows up to 120 Nodes on

a Bus

• Bus Pin ESD Protection Exceeds 14 kV HBM

• Unpowered Node Does Not Disturb the Bus

• Low-Current Standby Mode: 200-μA Typical

• Thermal Shutdown Protection

• Glitch-Free Power-Up and Power-Down CAN Bus

Protection for Hot-Plugging

• DeviceNet Vendor ID #806

(1) The signaling rate of a line is the number of voltage

transitions that are made per second expressed in bps (bits

per second).

2 Applications

• CAN Data Buses

• Industrial Automation

• SAE J1939 Standard Data Bus Interface

• NMEA 2000 Standard Data Bus Interface

3 Description

The HVD251 is intended for use in applications

employing the Controller Area Network (CAN) serial

communication physical layer in accordance with the

ISO 11898 Standard. The HVD251 provides

differential transmit capability to the bus and

differential receive capability to a CAN controller at

speeds up to 1 megabits per second (Mbps).

Designed for operation in harsh environments, the

device features cross-wire, overvoltage and loss of

ground protection to ±36 V. Also featured are

overtemperature protection as well as –7-V to 12-V

common-mode range, and tolerance to transients of

±200 V. The transceiver interfaces the single-ended

CAN controller with the differential CAN bus found in industrial, building automation, and automotive

applications.

Rs, pin 8, selects one of three different modes of

operation: high-speed, slope control, or low-power

mode. The high-speed mode of operation is selected

by connecting pin 8 to ground, allowing the

transmitter output transistors to switch as fast as possible with no limitation on the rise and fall slope.

The rise and fall slope can be adjusted by connecting

a resistor to ground at pin 8; the slope is proportional

to the pin's output current. Slope control with an

external resistor value of 10 kΩ gives about 15-V / μs

slew rate; 100 kΩ gives about 2-V/μs slew rate.

If a high logic level is applied to the Rs pin 8, the device enters a low-current standby mode where the

driver is switched off and the receiver remains active.

The local protocol controller returns the device to the

normal mode when it transmits to the bus.