Abstract: A trimmable component network of switched parallel paths is described, each path contains a component, typically a resistor, with a portion of the component bypassed by fuses. The bypassed portion represents the same percentage of the component's value for each of the trimmable components in the parallel paths. A component is measured against a specification and if the specification is not met a prescribed number of fuses are cut to bring the component within its specification. A TRIM CODE may be used to identify the specific fuses to be cut, and thus the specific fuses that are to remain intact. The same TRIM CODE is applied to the components in the parallel paths.

Abstract: This document discusses, among other things, a multiple accessory detection apparatus and methods for identifying accessories coupled to a multi-pin connector of an electronic device. The apparatus can include a first reference generator, a second reference generator, a plurality of switches to couple an output of the second generator to an accessory device and a comparator. The comparator can generate identifying information about the accessory device using the reference information received from the first reference generator and test information received using the second reference generator.

Abstract: A trimmable component network of switched parallel paths is described, each path contains a component, typically a resistor, with a portion of the component bypassed by fuses. The bypassed portion represents the same percentage of the component's value for each of the trimmable components in the parallel paths. A component is measured against a specification and if the specification is not met a prescribed number of fuses are cut to bring the component within its specification. A TRIM CODE may be used to identify the specific fuses to be cut, and thus the specific fuses that are to remain intact. The same TRIM CODE is applied to the components in the parallel paths.

Abstract: An over-current protection circuit is disclosed that provides a current limit threshold using resistors in the path of a scaled mirror current of a load current. The protective circuit has a first state that passes a supply source to a device, but when the threshold is reached the circuit becomes a feedback circuit that allows only a set final current to be passed to the device. When the load current reaches the threshold, the mirror current reaches a corresponding threshold that triggers a comparator and circuitry that then limits and fold backs the load current.

Abstract: This document discusses, among other things, a charging emulator configured to be coupled to an electrical interface, the charging emulator including a control circuit configured to receive information about a peripheral device coupled to the electrical interface and a charger circuit configured to provide power to the electrical interface using the received peripheral device information. In an example, the charging emulator can include a component of a host device including a low-power state, and the charger circuit can be configured to provide power to the electrical interface when the host device is in the low-power state.

Abstract: The present invention employs identically sized mirror transistors arrange in groups that may be preferentially addressed and activated to determine the value of a resistor. Known current are directed through the resistor, and the voltage developed is measured by comparing against a reference voltage. The current is increased or decreased by the least significant value until the voltage across the resistor matches the reference voltage. A successive approximation or other known technique may be used instead. A reference current is developed that temperature stable and that is trimmed when manufactured to reduce process effects. The reference voltage may be constructed to be independent form a local power source so that the system is relatively independent of process, voltage and temperature, PVT.

Abstract: A tunable, low power clock generator employs a voltage regulator, one or current generators and a variable resistor bank that, together, produce a control voltage for trimming a VCO. The control voltage is arranged to also compensate, at least, for the variables of temperature, supply voltage and fabrication processes as they affect the VCO output frequency. The current generator is well characterized over the variables discussed and the resistor bank is a flexible series/parallel array of resistors made from differing materials exhibiting different temperature coefficients. The resistor bank provides for various overlapping resistance values simultaneously with various overlapping temperature coefficients wherein the temperature coefficient profile of the clock generator over frequency and temperature is controlled.

Abstract: A supply voltage level detection circuit makes use of an additional supply already provided for power. A voltage detection circuit defines a first threshold, and a differencing circuit defines a second threshold. The output state of the differencing circuit is saved in a latch. The latch may be cross coupled gates of cross coupled inverters. When inverters are used, the differencing circuit output contends with the internal latch drive when setting or resetting the latch. The design allows the differencing circuit to overcome the inverter's internal drives to change the logic state of the latch.

Abstract: A tunable, low power clock generator employs a voltage regulator, one or current generators and a variable resistor bank that, together, produce a control voltage for trimming a VCO. The control voltage is arranged to also compensate, at least, for the variables of temperature, supply voltage and fabrication processes as they affect the VCO output frequency. The current generator is well characterized over the variables discussed and the resistor bank is a flexible series/parallel array of resistors made from differing materials exhibiting different temperature coefficients. The resistor bank provides for various overlapping resistance values simultaneously with various overlapping temperature coefficients wherein the temperature coefficient profile of the clock generator over frequency and temperature is controlled.

Abstract: A process for preparing a transalkylation catalyst, the catalyst itself, and a transalkylation process for using the catalyst are herein disclosed. The catalyst comprises rhenium metal on a solid-acid support such as mordenite, which has been treated with a sulfur-based agent. Such treatment reduces the amount of methane produced by metal hydrogenolysis in a transalkylation process wherein heavy aromatics like A9+ are reacted with toluene to produce xylenes. Reduced methane production relative to total light ends gas production results in lower hydrogen consumption and lower reactor exotherms.

Abstract: This invention is drawn to a process for isomerizing a non-equilibrium mixture of alkylaromatics in two sequential zones, the first zone operating in the absence of hydrogen using a platinum-free catalyst and the second zone using a catalyst comprising a molecular sieve and a platinum-group metal component to obtain improved yield of para-xylene from the mixture relative to prior art processes.

Abstract: In processes for recovering one or more xylene isomers and isomerizing the remaining isomers for recycle, the isomerate is distilled to provide a toluene-containing overhead, a mid-boiling fraction containing C8 aromatics and a bottoms fraction containing C8 aromatics and C9+ aromatics. The mid-boiling fraction is recycled to the unit for recovering the sought xylene isomers and has sufficiently low content of C9+ aromatics that the separation feed to the unit for recovering the sought xylene isomers contains up to about 500 ppm-mass C9+ aromatics. The processes provide a high quality xylene isomer product while achieving at least one of debottlenecking, energy savings and capital savings.

Abstract: A supply voltage level detection circuit makes use of an additional supply already provided for power. A voltage detection circuit defines a first threshold, and a differencing circuit defines a second threshold. The output state of the differencing circuit is saved in a latch. The latch may be cross coupled gates of cross coupled inverters. When inverters are used, the differencing circuit output contends with the internal latch drive when setting or resetting the latch. The design allows the differencing circuit to overcome the inverter's internal drives to change the logic state of the latch.

Abstract: A process for isomerizing ethylbenzene into xylenes such as para-xylene using a zeolitic catalyst system based on low Si/Al2 MTW-type zeolite that preferably is substantially free of mordenite. The catalyst may be bimetallic where the two metals are platinum and tin.

Abstract: A process for preparing a transalkylation catalyst, the catalyst itself, and a transalkylation process for using the catalyst are herein disclosed. The catalyst comprises rhenium metal on a solid-acid support such as mordenite, which has been treated with a sulfur-based agent. Such treatment reduces the amount of methane produced by metal hydrogenolysis in a transalkylation process wherein heavy aromatics like A9+ are reacted with toluene to produce xylenes. Reduced methane production relative to total light ends gas production results in lower hydrogen consumption and lower reactor exotherms.

Abstract: A catalyst, and a process for using the catalyst, that effectively converts and transalkylates indane and C10 and heavier polycyclic aromatics into C8 aromatics is herein disclosed. The catalyst comprises a solid-acid support such as mordenite plus a metal component such as rhenium. The catalyst provides excellent conversion of such heavy aromatic species as naphthalene, which is also observed by a decrease in the ending-boiling-point of a hydrocarbon stream passed over the catalyst. The same catalyst is also effective for transalkylation of lighter aromatics, thus yielding a valuable xylenes product stream out of the process.

Abstract: The use of transalkylation catalysts to react heavy aromatic compounds of carbon number nine (and heavier carbon numbers) with benzene to form carbon number eight aromatics is disclosed. The catalyst system preserves ethyl-group species on the heavier aromatics that are otherwise de-ethylated over most gas-phase transalkylation catalysts to form undesired ethane gas with benzene or toluene. The catalyst system also promotes methyl-group species transalkylation at selected conditions. Thus, by using the transalkylation system, a greater yield of para-xylene or other carbon number eight aromatics may be achieved overall within an integrated aromatics complex.

Abstract: A liquid or partially liquid phase process for isomerizing a non-equilibrium mixture of xylenes and ethylbenzene uses a zeolitic catalyst system preferably based on zeolite beta and on pentasil-type zeolite. The invention obtains an improved yield of para-xylene from the mixture relative to prior art processes in a more economical manner. A preferred beta zeolite is a surface-modified zeolite beta resulting from acid washing of a templated native zeolite at conditions insufficient to effect bulk dealumination. A preferred pentasil zeolite is a MTW-type with a silica-to-alumina ratio between 20 and 45.

Abstract: A process for isomerizing ethylbenzene into paraxylene using a zeolitic catalyst system based on MTW-type zeolite that is substantially free of mordenite. The invention obtains an improved yield of paraxylene without excess benzene production by dealkylation. The zeolitic silica-to-alumina ratio ranges from 20 to 45. Elimination of mordenite in the catalyst improves yields and integrated aromatics complex economics by reducing undesirable aromatic ring-loss reactions as well.

Abstract: A liquid or partially liquid phase process for isomerizing a non-equilibrium mixture of xylenes and ethylbenzene uses a zeolitic catalyst system preferably based on zeolite beta and on pentasil-type zeolite. The invention obtains an improved yield of para-xylene from the mixture relative to prior art processes in a more economical manner. A preferred beta zeolite is a surface-modified zeolite beta resulting from acid washing of a templated native zeolite at conditions insufficient to effect bulk dealumination. A preferred pentasil zeolite is a MFI-type.