Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Networks

Optocouplers feature highest CMR rating

Posted: 27 Jan 2006 ?? ?Print Version ?Bookmark and Share

Keywords:FOD0708? FOD0738? optocoupler? Fairchild Semiconductor?

The new FOD0708 (single-channel) and FOD0738 (dual-channel) 15MBd optocouplers from Fairchild Semiconductor are touted to feature the industry's highest common-mode noise rejection (CMR) rating, while providing the high-bandwidth (15Mbps), low-power-consumption characteristics demanded by industrial control applications.

According to the company, its patented Optoplanar technology reduces package capacitance by more than 30 percent compared to competitive solutions. This low package capacitance leads to a guaranteed 25KV/?s minimum CMR rating that is said to be two-and-a-half times higher than the closest competitor, allowing the FOD07X8 series to operate in noisy industrial environments. Unlike open collector bipolar-equivalent solutions, added Fairchild, these optocouplers feature a push-pull detector that eliminates the need for a pull-up resistor and the power-consuming current it draws.

"Noise can cause data errors in industrial control environments, adversely affecting applications such as line receivers on an automated factory floor," said John Constantino, manager of Fairchild's optoelectronics product Line. "The FOD07X8 optocouplers offer our customers the industry's best available common-mode noise immunity to solve this problem. To address the other key requirements of the industrial market, we developed our new 15MBd optocouplers with a push-pull configuration that reduces power consumption without penalizing bandwidth."

The electrical characteristics of the FOD07X8 product series are guaranteed beyond the full industrial temperature range (-40C to 100C). Their performance makes these devices suitable for interfacing with microprocessors, peripheral I/O and other high-speed applications. They are also well-suited for industrial networks such as Profibus, Fieldbus, DeviceNet and SDS.

The optocouplers' high-speed LED and a high-speed photodetector utilize the company's proprietary 0.8?m CMOS technology. Compared to typical face-to-face optocoupler/LED combinations, the FOD07X8 devices employ a side-by-side Optoplanar configuration and integrated proprietary silicon design on the detector chip. The resulting package capacitance enables these optocouplers to deliver excellent 50KV/?s common-mode immunity when a 2KV (peak) pulse is applied. These devices are available in a compact S0-8 package, with the dual-channel FOD0738 offering optimum mounting density. They also offer a 2500VRMS isolation voltage rating and UL-certification for increased reliability.

The FOD0708 and FOD0738 are Pb-free products that meet or exceed the requirements of the joint IPC/JEDEC standard J-STD-020B and are compliant with the European Union now in effect.

The FOD0708 is priced at $1.45, while the FOD0738 is available for $2.83.

Article Comments - Optocouplers feature highest CMR rat...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top