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GDSII conversion is a one-way process for PCells, because once converted to GDSII, the layout is just like any other layout cell. In most cases, even the original tool cannot recognize the layout data as a PCell. In fact, users of tools with a proprietary database must pay annual licensing fees to the tool vendor for the life of the design in order to view or modify their own PCells! Effectively, this amounts to a ransom” for the missing PCells.

MTMM-140-13-T-D-225_Datasheet PDF

GDSII conversion is a one-way process for PCells, because once converted to GDSII, the layout is just like any other layout cell. In most cases, even the original tool cannot recognize the layout data as a PCell. In fact, users of tools with a proprietary database must pay annual licensing fees to the tool vendor for the life of the design in order to view or modify their own PCells! Effectively, this amounts to a ransom” for the missing PCells.

3. SC-RJ connecting system from Reichle & De-Massari AG (R&M), Switzerland or Phoenix, Germany.

4. Full evaluation board details are described in the Avago Technologies application Note 5325 found at: http://www.avagotech.com/docs/AV02-0416EN.

MTMM-140-13-T-D-225_Datasheet PDF

Energy-saving technologies have been the focus of today's electronics, particularly in the area of standby power consumption. Standby power consumption is important since many electronic devices are in standby mode a great deal of time, and this is where there can be tremendous opportunities to save power.

To reduce standby power and meet the latest ENERGY STAR specifications, Fairchild has incorporated several clever features to enhance the performance of flyback converters and achieve under 30 mW power consumption at standby mode with 230 Vac input for most SMPS (switched mode power supplies ) designs. These innovations include high-voltage startup circuitry, ultra-deep burst mode at light load, low operating current at light load, and a patented HV device discharging X-cap Ax-CAP™ technique to save external parts, and give engineers added reliability and a lower BOM cost when compared to solutions using discrete components.

This article examines the ENERGY STAR specifications, and provides an analysis of the areas where the losses occur. It then shows how losses in these areas were minimized. The article is presented as a pdf file (no registration required). To read it, click here .

MTMM-140-13-T-D-225_Datasheet PDF

About the authorsMing-Chang Tsou is currently a system application senior engineer with Fairchild Semiconductor, HsinChu City, HsinChu County, Taiwan. He has more than 4 years of experience in power-electronics technology. His research interests including design of high-performance power converters and green-mode PWM controllers.

Tim Lee (ChungChang Lee) is a staff application engineer for the power-conversion group at Fairchild Semiconductor. He has over 5 years of experience working in power conversion in Taiwan. His research interests include the design of high-performance power converters and green-mode PWM controllers.

MTMM-140-13-T-D-225_Datasheet PDF

Kenny Chan (Chenhui Chan) is a product line manager for the power conversion group at Fairchild Semiconductor. He has over 7 years experience in all aspects of the power-conversion business.

PCell caching in a multi-vendor custom IC design environment

The IETF also has a Differentiated Services working group that works on QoS-related specifications. RFC 2475, An Architecture for Differentiated Services,” defines an architecture for implementing scalable service differentiation in an internetwork or the Internet. As Chapter 13, Optimizing Your Network Design,” covers in more detail, IP packets can be marked with a differentiated services codepoint (DSCP) to influence queuing and packet-dropping decisions for IP datagrams on an output interface of a router. RFC 2475 refers to these decisions as per-hop behaviors (PHB). The DSCP can have 1 of 64 possible values, each of which outlines a PHB, although on a real network you would only use at most 6 to 8 DSCP values.

Although the integrated services (RSVP) model, described in the previous section, offers finer granularity, it is less scalable than the differentiated service model. The integrated services model allows sources and receivers to exchange signaling messages that establish packet classification and forwarding state on each router along the path between them. State information at each router can be potentially large. The amount of information grows in proportion to the number of concurrent reservations, which can be a high number on high-capacity backbone links. Differentiated services doesn't require RSVP and can be utilized to aggregate integrated services/RSVP state in the core of a network.

RFC 2475 compares its approach to the relative priority-marking model used by such QoS solutions as the IPv4 precedence marking defined in RFC 791, IEEE 802.5 Token Ring priority, and IEEE 802.1p traffic classes. Compared to those solutions, the differentiated services architecture more clearly specifies the role and importance of boundary nodes and traffic conditioners, and uses a per-hop behavior model that permits more general forwarding behaviors than a relative priority. An example of relative priority is IPv4 precedence, which can range from routine (the bits are set to 000) to high (the bits are set to 111).

RFC 2475 also compares its approach to the service-marking model in the IPv4 Type of Service (ToS) bits. As defined in RFC 1349, applications can use the ToS bits to mark each packet with a request for a type of service (for example, a request to minimize delay, maximize throughput, maximize reliability, or minimize cost). The intent of those bits, which were never used, was to allow a router to select routing paths or forwarding behaviors that were suitably engineered to satisfy the service request. The differentiated services model, on the other hand, does not describe the use of the DSCP field as an input to route selection.

The ToS markings defined in RFC 1349 are generic and do not match the actual services that routers and service providers offer. Furthermore, the service request is associated with each individual packet, whereas some service semantics may depend on the aggregate forwarding behavior of a sequence of packets. The ToS marking model does not easily accommodate growth in the number and range of future services (because the codepoint space is small) and involves configuration of the forwarding behavior for each ToS in each core network node. The differentiated services model does not have these problems.

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