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smd resistor size

发帖时间:2021-06-15 01:23:10

Frank Robertazzi can be reached at frank_robertazzi@agilent.com.

Essentially it is a dual-band front end – 900 and 1,800 or 900 and 1,900 – but with a few additional components, a switch and wideband filter. It can be suitable for triple-band phones thatin 2000 will be in high demand,” said Yvan Droinet, international product marketing manager for RF products at Philips Semiconductors.

Droinet said Philips Semiconductors would use the N-ZIF architecture to address future developments in GSM, such as Edge (Enhanced Data rates for GSM Evolution), and was likely to use it for third-generation (3G) phones that will operate with carrier frequencies just above 2 GHz.

smd resistor size

It is strictly for GSM at the moment, but it would be no problem to extend the architecture to 3G,” he said. We would certainly consider near-zero IF for GSM/GPRS/Edge first and then for a GSM/Edge/UMTS transceiver on a single die.”

Philips said that it offers higher integration compared with traditional double-conversion superheterodyne receiver architectures, as well as advantages over direct conversion, also known as zero-IF.

A conventional IF configuration requires the use of an external SAW filter, while a single-conversion alternative can be implemented entirely on-chip.

smd resistor size

The intermediate frequency is 100 kHz, which provides an advantage in integrating the IF channel filter,” said Droinet. Compared with a zero-IF architecture, the advantage is that we don't need to do the calculations for the dc offset.”

The UAA3535, which operates at 2.5 V, interfaces to standard A/D converters and requires few external components. Droinet said that apart from three VCOs, available as single components, the design only required a power amplifier, an RF antenna filter and three loop filters composed of four or five capacitors and some decoupling capacitors to complete the RF section.

smd resistor size

The chip is being manufactured using Philips Semiconductors' 0.5-micron BiCMOS process. The UAA3535 delivers all the advantages demanded by today's handset manufacturers, excellent features, a high integration level and low cost, for next-generation GSM mobile phones,” Droinet said.

He said future iterations of its GSM chip sets will integrate new capabilities, such as Bluetooth, MP3and GPS, and will directly address 3G standards.

TI will offer the GTLP devices in a wide range of package options, including a small outline integrated circuit (SOIC), small-scale outline package (SSOP), thin small shrink outline package (TSSOP), thin very small outline package (TVSOP) and a low-profile fine-pitch ball grid array (LFBGA). This allows designers to increase the performance and functionality of a system without increasing the size of the daughter card, Blozis said.

TI believes the GTLP family will allow systems to be designed faster as Internet traffic rapidly increases throughput requirements. A lot of people use standard pinouts but they only support a certain frequency,” Blozis said. You'd have to do a large redesign of the equipment to get the higher data throughput.” The GTLP family devices allow use of existing boards and passive backplanes, with minor changes in the termination scheme. And because the GTLP family is backward compatible with existing devices, this will allow them to get the throughput with a smaller change required to the board.”

Several GTLP devices are sampling now, with additional devices to be added during the next few months. Prices, in 1,000s, range from a low of $4.70 for the 24-pin, 8-bit SN74GTLPH306 bus transceiver (available in February) to a high of $17.50 for the 114-pin, 36-bit SN74GTLPH32912 universal bus transceiver (available in June).

Once again, the semiconductor industry is plumbing the depths of one of its untamed business cycles.

Typically in this sector, erratic supply and demand cycles cause order backlogs to swell beyond six months, forcing suppliers to increase their capacity excessively. Measurements of real consumption are lost as customers and distributors rush to place orders just to get in line for shipments. Then, on the downswing, those phantom orders collapse, shipment projections are missed and a good deal of manufacturing capacity becomes idle. The figure below demonstrates the increasing volatility of orders as they move up the supply chain from the consumer to the vendor who supplies a manufacturer.

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