TECHNOLOGY ROUNDUP

Transmitters, Receivers and Transceivers

This round-up of recent developments in the communications arena looks at Avago’s latest low cost transmitter for direct fibre connection; power efficient RS-485/RS-422 receivers from Intersil; and a range of automotive qualified CAN transceivers from Texas Instruments.

The SFH757V from Avago Technologies is a low-cost transmitter for simple optical data communications via Polymer Optical Fibre (POF). The device is available in two versions, allowing interfacing with standard 2.2mm POF either by gluing or via an axial locking screw (SFH757V). This very robust 650nm LED can be used for communication at speeds of up to 100Mbit/s, making it suitable for use in household and industrial electronics, optical networks, and any situation where EMI is a concern.


Figure 1 the SFH757V Low-Cost Optical Data Transmitter from Avago

Features

• Low-cost 650nm transmitter with high-speed LED
• Data rate up to 100Mbit/s
• Interfaces easily with 2.2mm plastic fibre
  • V-housing with axial locking screw
  • Clear package with integrated micro lens and aperture
• Light-tight housing for superior crosstalk
• Auto insertable and wave solderable
• RoHS compliant

The ISL328xE series of single RS-485/RS-422 receivers from Intersil provides IEC61000 ESD protection on its inputs, while drawing 30 times less power than competing devices. Supplied in small SOT-23 and TDFN packages, the devices are designed to conform to the ±16.5kV air gap and ±9kV contact ESD specifications within IEC61000. They are fully featured receivers that provide 1/8 unit load input resistance (allowing up to 256 devices on the bus) and full fail-safe (open, short and terminated but undriven). All operate from a wide supply range of 3.0V to 5.5V and at data rates up to 20Mbit/s.


Figure 2 Intersil's ISL328xE series RS-485/RS-422 receivers

Features

• Single RS-485/RS-422 receivers
• IEC61000 ESD protection on inputs: ±16.5kV air gap; ±9kV contact
• Low power: 500µA quiescent, 20µA standby
• Space-saving 3mm x 3mm SOT-23 and 2mm x 3mm TDFN packages
• 1/8 unit load input resistance
• Full fail-safe: open, short terminated but undriven
• Wide supply range: 3.0V to 5.5V
• Data rates up to 20Mbit/s
• On-chip level translators
• Industrial (-40ºC to +85ºC) and extended industrial (-40ºC to +125ºC) temperature ranges

Texas Instruments offers Controller Area Network (CAN) products with full qualification to automotive grade Q100. The range includes the SN65HVD1040-Q1, a high-speed transceiver that meets or exceeds the specifications of the ISO 11898 standard and is an enhanced drop-in replacement for commonly used eight-pin devices.

The SN65HVD1040-Q1 provides differential transmit capability to the communications bus and differential receive capability to a CAN controller at signalling rates of up to 1Mbit/s. Designed for operation in the harsh environments commonly encountered in automotive applications, the device features over-temperature, cross-wire, over-voltage and 'loss of ground' protection from -27V to +40V. In addition, it boasts a common mode range of -12V to +12V and can withstand voltage transients from -200V to +200V, in accordance with ISO7637.


Figure 3 Automotive Qualified CAN Tranceivers from Texas Instruments

Features

• Automotive qualified CAN transceiver
• Meets or exceeds the requirements of ISO 11898-5
• Low power (less than 12µA) standby mode with bus wake up
• Tested in accordance with ISO 7637
• ESD protected bus pins (±8kV HBM)
• Bus fault protection of -27V to +40V
• Dominant time-out function
• Customer-specific configuration control and major-change approval support
• High ElectroMagnetic Immunity (EMI)
• Low ElectroMagnetic Emissions (EME)
• Thermal shutdown protection
• Power-up/down glitch-free bus inputs and outputs
• High input impedance with low V_CC
• Monotonic outputs during power cycling

For further information, including Datasheets on the featured products, the Avago Plastic Fibre Components Application Note, and details of how to obtain Samples of the SN65HVD1040-Q1, please click here