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Industry’s first micro serdes delivers low power and low EMI

South Portland, Maine — Fairchild Semiconductor announced an innovative new line of ultra-compact serializers/deserializers called μSerDes (micro-SerDes).

The FIN12 and FIN24 series devices are suited for solving the increasingly complex design challenges posed by converging product features in ultra-portable and consumer applications. These devices reduce traditionally wide parallel paths of data to a high-speed serial link, reducing the interconnection to six to seven times fewer wires.

The serial link is implemented using electromagnetic interference (EMI)-reducing differential technology that can result in faster electromagnetic compatibility (EMC) regulatory system approval. This highly flexible interface solution can easily be implemented across multiple display platforms allowing for a shortened product development cycle and speeding time to market.

The serdes also lowers overall component count and board-space requirements, helping to optimize the size and cost efficiency of cell phones, digital cameras, printers and other space-sensitive applications.

Standby power consumption, using Fairchild's serdes, is 10 times lower than any other solution, a critical parameter affecting battery life and cell phone talk time, said Michael Fowler, a member of Fairchild's technical staff.

The devices can reduce EMI by 30 to 40 dB at the fundamental frequency as well as reduce troublesome harmonics to less than -100 dBm, resulting in greater EMC. These enhancements are achieved through serialization architectural innovations and by offering two innovative differential I/O technologies, low power low-voltage differential signaling (LpLVDS) and current transfer logic (CTL), that reduce power and EMI compared to traditional I/O technology.

“Developed in close cooperation with a number of key customers, μSerDes provides designers with an excellent migration path to superior performance and functionality, including more efficient power management, lower EMI and smaller packaging,” Fowler said.

Key features of μSerDes include:

  • Lowest EMI for minimal noise emission, less wireless interference such as receiver desense and quicker time to market;
  • Lowest power consumption, extending battery life;
  • Serialized data rates up to 780 Mbits/s;
  • Significant cable/signal reduction, >25:4 for unidirectional interfaces; >50:7 for bidirectional;
  • Greater flexibility, works with both pixel and microcontroller interfaces;
  • Configurable as a serializer or deserializer with minimal power up/down sequences;
  • No special transmission media required: works with typical flex circuits, PC boards, cables;
  • Smallest packaging-space-saving 32- or 40-terminal MLP or 42 BGA;

Production for the CTL versions will commence first, followed by the LpLVDS versions. All of the devices will be available in production quantities in May.

Pricing for all of the devices, which are sampling now, is $1 each in 1,000s. Click here for the FIN12A data sheet. Click here for the FIN24A data sheet. Click here for the FIN24C data sheet.

Fairchild Semiconductor , 1-207-775-8100, www.fairchildsemi.com.

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Fairchild Semiconductor is trumpeting the industry's first ultra compact differential serializers/deserializers for battery powered portable applications — especially cell phones.

These micro-serdes devices are offered in a tiny package (3.5mm x 4.5mm) 42-pin BGA, can reduce EMI by 30 dB to 40 dB, versus a single-ended solution, and consume little power.

Increasing functionality in cell phones is resulting in more signals, at higher speeds through smaller spaces. These serdes devices enable transmission of wide parallel paths of bidirectional data between two endpoints, reducing required signaling to a small number of wires.

“Using these devices can cut down the number of wires that go through the hinge of a cell phone — from as many as 96 wires — down to two or three differential pairs (i.e. four to six individual wires) and one or two control signals,” Fowler said.

The differential I/O technologies that Fairchild is utilizing in its latest serdes family offer many advantages over traditional LVDS technology, Fowler said.

The company's proprietary CTL-based I/O technology, for instance, results in ultra low swing (50 mV typical), compared to 200 mV, which is the lowest voltage swing possible using voltage difference receivers, Fowler said. In the near future, Fairchild expects to lower the swing to between 20 mV and 30 mV, he said.

Furthermore, there is a 70 percent power reduction and -20 dB lower EMI emission over LVDS technology, Fowler added. “Standby power is so low at 100 nA, in fact, that it has virtually no effect on the battery life at all,” he said.

Fairchild is also utilizing its own low power version of LVDS (LpLVDS). Although traditional LVDS does not provide efficient power consumption (350 mV swing) for ultra portable applications, Fairchild's LpLVDS provides low swing (250 mV) and slower edge rates, as well as two times lower EMI. The LpLVDS versions also have the additional benefit of allowing AC coupling with DC balance capability.

Reducing EMI has eliminated the need for EMI filters, voltage level translators and shielding. “The level translators can be replaced since the μSerDes can accept any input voltage from 1.65 V to 3.6 V and output any voltage in the same range. The shielding and the EMI filters can be eliminated because of our extremely low EMI, especially in the higher harmonics that would be in the range of the cell phone radio signal,” Fowler said.

Combining the serializer/deserializer is another unique feature of the μSerDes family, according to Fowler. “There are cases where the customer wants to send info in both directions, so having a SerDes on each side (rather than a serializer or deserializer) allows this to be done without using four devices,” he explained.

The company also integrated the encoded word boundary into the serdes so a second phase-locked loop (PLL) wouldn't be needed, Fowler said. The encoding scheme also assures that the word boundary is never lost.

In the second half of this year, Fairchild will release its low power serdes devices, which are currently in the milliamps range but will be moving toward the microamps range shortly, Fowler said. Next year, Fairchild will include multichannel versions of its serdes line for a variety of interfaces.

To date, Fairchild's serdes offering consists of six devices. The FIN12A, FIN24A and FIN24 devices are available in 12-, 22- and 24-bit versions, utilizing the LpLVDS serial I/O, and are offered in either molded leadless packaging (MLP) or 42-pin BGA (3.5mm x 4.5 mm). The FIN12AC, FIN24AC, and FIN24C versions are being offered in the CTL-serial I/O.

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