acquisitionZONE Products for the week of November 15, 2004
Agilent Technologies Inc. introduced the industry's first 3.3 V, 15 MBd, multi-channel and bi-directional digital optocouplers for use in a wide range of consumer, computing, communications and industrial applications. Agilent's patented manufacturing technology for stacking LEDs provided the integration breakthrough necessary to develop multi-channel optocouplers that allow OEMs to reduce part count, board space and system costs. The integration of two, three and four optocouplers is achieved through stacking LED die and an insulating layer on a silicon substrate.
Optocouplers provide electrical (galvanic) isolation of signal lines to protect low-voltage circuitry from high-voltage surges. They operate by converting electrical signals into optical signals that are transmitted across a transparent insulating material and then converted back to electrical signals. They also eliminate electrical noise and interference.
"Technology breakthroughs such as stacked LEDs set new optoisolation benchmarks for our competitors," said Chong Tze Siong, vice president and general manager of Agilent's Isolation Products Division. "Offering multi-channel devices reduces the number of packaged parts on our customers' boards, saving space and cost. We will maintain our market leadership by introducing new products that offer value-added integration benefits."
The ACSL-6xx0 series optocouplers provide minimum 10 MBd operating speeds, with 15 MBd typical performance. With an insulating material between the LED and active circuitry, the optocoupler provides safe, high-voltage insulation performance. The series includes dual-, triple- and quad-channel versions. They are supplied in compact 8-pin (4.9 mm x 5.9 mm x 1.7 mm for dual-channel) and 16-pin (9.9 mm x 5.9 mm x 1.7 mm for triple- and quad-channel) thin small outline integrated circuit (SOIC) packages to further reduce board-space requirements. The optocoupler's bi-directional capability simplifies signal routing on PC boards.
In computer systems, the Agilent ACSL series optocouplers provide the
benefits of reduced part count and board space for parallel interfaces and
serial interfaces such as RS232/485/422, SPI (serial peripheral interface),
and Inter-Integrated Circuit (I2C) bus. They offer the same benefits in
industrial, test and measurement, and medical systems for PLC (programmable
logic controllers), fieldbus interfaces and data acquisition; in communications
applications such as POE (power-over-Ethernet) and networking boards; and
for plasma display panels and other consumer appliances.
analogZONE Says . . .
Hewlett-Packard has been the industry leader in optocouplers for a long while and the HCPL-numbered parts have also been second-sourced by others although not matching the isolations achieved by HP. The latest parts from Agilent also move the numbering which has now been changed to ACSL (Agilent coupler special LED). But Agilent has thrown down a large gauntlet with these new parts; multiple channels… that is, a capability of more than 2.
70% of Agilent's optocoupler business comes from the industrial sector and while there have been applications in the medical, communications and consumer markets it has been rather limited. With the advent of the larger plasma display panels (PDPs) the consumer market has burst open.
The parts are rated at 15 Mbaud which Agilent continues to shorten to MBd -- mega-bel-deci? -- and using bauds anyway in the year 2004 is confusing and misleading when the unit is as close to obsolescence as you can get. If the parts are capable of data rates of 15 Mbit/s I wish they would say so; if that's not what is meant perhaps they could explain what they do mean.
Notwithstanding, this multi-channel development is going to leave the competition (Vishay, Fairchild, Sharp and NEC) with their mouths gaping. For now, the channels are independent modules within the IC, but Agilent made it clear they were going to do something about that. Until then the cost structure will be limiting. The company has been able to get past the two channel hurdle with the development of a patented stacking technology for the LEDs. Dual, triple and quads will be available in the series with six different device configurations. The two released parts, here, are the dual bidirectional ACSL-6210 and quad unidirectional ACSL-6400. A later release will also have the triple bidirectional (2/1) ACSL-6310, the triple unidirectional ACSL-6300, the quad bidirectional (2/2) ACSL-ACSL-6420, and the quad bidirectional (3/1) ACSL-6410.
Why have bidirectional? Because it makes the design of the PCB routing very much easier. An I2C interface, for example, in a noisy or voltage sensitive application like hot-swapping would ideally use the ACSL-6310 (2/1), while a video application would use an ACSL-6300 or the ACSL-6400 if there was a separate synchronizing channel to be isolated. Isolation between an ADCs output to, and a 3-wire serial control system from a micro could use an ACSL-610 (3/1).
The maximum working insulation voltage of the devices is 560 Vpk, with a 10 s allowable overload of 4 kVpk. The operating voltage can be between 3.0 V and 5.5 V with an input current (high-level) at 15 mA maximum. The propagation delay time is 100 ns maximum to either logic high or low. The leakage from input to input is a typical 5 nA.
The dual ACSL-6210 is in an SO-8 package while the triples and quads will be in a low profile SO-16.
There is no doubt that this family will do exceptionally well for the company. It is a major step forward in the technology of optocouplers and puts Agilent way ahead of the competition, who are going to feel immediate pricing pressure put on the single and dual optocouplers of yesterday. As always they will find winning sockets in industrial, T&M, medical, computing, communications and, increasingly, in consumer products from PDPs to white goods.
The ACSL-6400 and ACSL-6210 are in production priced at 4.14 and $2.53, respectively, in 10-k piece lots.