NXP Boosts EPC Gen 2 Tag Memory, Performance

By Claire Swedberg

The semiconductor maker's two new RFID chips require less power to operate and work across the entire UHF RFID frequency range, from 840 to 960 MHz. One chip offers 512 bits of user memory.

NXP Semiconductors has released a pair of Gen 2 UHF RFID chips—models Ucode G2XM and Ucode G2XL—offering a greater read range and improved read rates. According to the company, both chips will perform over the entire UHF RFID frequency range, from 840 to 960 MHz. NXP designed the latest members of its Ucode family of UHF RFID tags to be more sensitive to RF signals (thereby increasing read rates and read range), and to operate in dense reader environments in which tags receive transmissions from multiple interrogators simultaneously. In the case of the G2XM, NXP claims, the chip provides more memory than other Gen 2 chips currently available.

In December 2005, NXP's precursor—the Philips Semiconductors division of Royal Philips Electronics—released the first Gen 2 UHF chip in its Ucode family. That chip offered a total of 512 bits of memory, including 96 bits for an EPC number, 224 bits programmable by the user, 64 bits for a tag identifier (TID) and 64 bits reserved for access and kill passwords. The two latest chips, says Jan-Willem Reynaerts, NXP's general manager for RFID, are the result of improvements developed at the NXP RFID Reference Design Center, located in Austria. The center, Reynaerts says, enabled NXP to develop a better chip by using several different interrogators and reader antennas to test tags made with Ucode chips.

End users have been seeking a UHF RFID chip that would allow them to store more data, Reynaerts notes, as well as attain read rates closer to 100 percent. Airports, airline manufacturers and other organizations that track tagged returnable assets typically need to input a great deal of data on their RFID tags, which do not always have enough memory to accommodate them.

The two new Ucode chips each come with a 64-bit preprogrammed unique tag identifier serial number. In response to customer requests for additional flexibility regarding the memory devoted to EPC numbers, Reynaerts says, the chips are capable of "scaling up" to a 240-bit EPC, enabling users to program different EPC codes for multiple applications. Because the chips will be sold globally, he adds, NXP designed them to operate across the entire UHF RFID frequency range, from 840 to 960 MHz, to be operable under disparate regulations around the world.

What's more, the chips feature increased sensitivity to the RF signals transmitted by an RFID interrogator, and require only about 30 microwatts of power to operate, compared with the 50 microwatts needed for NXP's first Gen 2 chip. "The processes we use have been optimized to allow us to minimize current consumption," Reynaerts states. With such greater sensitivity, he explains, the maximum read range for tags made with either chip is about 20 to 30 percent longer than that for any other Gen 2 chip presently on the market. The chips are alike in every way but one: The G2XM offers 512 bits of programmable user memory, which NXP says is more than any other Gen 2 tag currently available.

To improve performance in dense reader environments, NXP increased the chip's ability to cut off undesired reader transmissions. "We improved the filter function of the chip in order for it to operate so well, " Reynaerts explains. "Compared to the old chip, we made major improvements on filter functionality."

RFID tag makers will join the chips to antennas to produce RFID inlays and convert them into RFID labels. The chips have been tested by such manufacturers as KSW Microtec, RF Identics, RSI ID Technologies, Tagsys and UPM Raflatac. Reynaerts says most of these tag manufacturers have already developed labels and suites of labels for the new chips, and are prepared to sell them within weeks.

The NXP release follows several other upgrades offered by Gen 2 chip manufacturers in the past year. In August 2006, Impinj launched two RFID chips—the Monaco/64 and Monza/ID—offering 64 bits of user-programmable data in addition to memory for a 96-bit EPC (see Impinj Introduces Two New Gen 2 Chips).

That same month, STMicro began shipping its XRAG2 EPCglobal Gen 2-certified chip (see STMicro Ramps Up Production of Its XRAG2 Chip), which features 432 bits of memory and is available with either three memory banks (64 bits for a tag identifier, or TID; 304 bits for the EPC number; and 64 bits reserved) or four (128 bits of user memory, 64 bits for TID, 176 bits for EPC number and 64 bits reserved).

However, Reynaerts notes that the Ucode G2XM user memory alone is 512 bits. That, plus a 240-bit EPC memory area, a 64-bit TID, a 32-bit access password and a 32-bit kill password, brings the total memory to 880 bits. The G2XL has a total memory of 368 bits: a 240-bit EPC memory area, a 64-bit TID, a 32-bit access password and a 32-bit kill password.

"We want to show that we believe in the RFID market," Reynaerts states. "We continue to develop the UHF product, and we think the technology has tremendous potential."

According to Reynaerts, the chip is available to label manufacturers now, at a cost less than that of previous Ucode chips. Prices, he says, "will be extremely competitive." The G2XL will cost $0.043 apiece in high-volume orders, with the higher-memory G2XM costing about 25 percent more. Both models are expected to earn Gen 2 certification from EPCglobal within the next few weeks.