Abstract: A control circuit and a control method of a switching power supply, according to feedback signals on a pin FB and a pin CS, a constant current control module generates and outputs a control signal to control an output current of the switching power supply, thereby regulating duty cycle of a first transistor adaptively and controlling an output current Io of a power supply system to be constant; according to the feedback signals on the pin FB and on the pin CS, a constant current precision compensation module adaptively regulates circuit parameters of the constant current control module and a sample-and-hold module, preventing precision of constant current output from being influenced by change of a working mode and/or by variation of input conditions; when an output voltage changes, QR mode keeps unchanged or depth of a CCM keeps approximately constant.

Abstract: Disclosed is a high voltage power system with enable control, comprising a high voltage start-up circuit, a PWM control module, and a driving module; the high voltage start-up circuit comprises a first transistor, a third transistor, a fourth transistor, a resistor, a diode, a VDD detection unit and an I/O interface unit; the high voltage start-up circuit is controlled by an input of a pin EN; when the pin EN is set, the high voltage start-up circuit stops working; the power system is shut off and doesn't restart, and enters a zero standby state; when the pin EN is reset, the high voltage start-up circuit restores to work, and the power system restarts and enters a normal working state. The power system having the high voltage start-up circuit with enable control has characteristics that the standby input power consumption and standby input current are both close to zero.

Abstract: Disclosed is a short-circuit protection circuit for a voltage sampling resistor of a primary side converter, comprising a high voltage power transistor, a high voltage starting resistor, a first voltage dividing resistor of a port VDD, a second voltage dividing resistor of the port VDD, an NMOS transistor, a diode, a first comparator, a second comparator, a third comparator, a time delay circuit, a filter, a first logic circuit, a second logic circuit, a current supply, a first AND gate and a first inverter. The chip of the present disclosure is capable of correctly and effectively detecting whether the sampling resistor is shorted or not before the chip works normally, thereby avoiding the risk of damaging the chip by large current from the voltage feedback port FB due to turn-on of the switching transistor when the upper voltage sampling resistor is shorted, and greatly reducing the input power.

Abstract: The present disclosure relates to a circuit structure for enhancing EFT immunity of primary side converter, including a power ground and a feedback voltage detecting block, a feedback current detecting block, a controller, a PWM driving block, a high voltage starting block, a starting unit, a circuit for enhancing EFT immunity of primary side converter, a power MOS transistor, and an OR gate configured to perform a logical OR of an off-time calculated theoretically and an off-time output by an off-time control block. The present disclosure enhances EFT immunity effectively and improves the dynamic characteristics of the primary side converter.

Abstract: A switched capacitor circuit is described which is programmable so that its function can be set by a user. Thus, control circuitry and selection circuitry are provided to enable one of a plurality of alternative control signals to be provided to switch circuits of the switched capacitor circuit. In this way, the function of the switched capacitor circuits can be altered. Where there are a plurality of switched capacitor circuits connected in an array, the topology of the array can be altered by suitably routing particular input signals to particular outputs by selecting the control signals to control the switched circuits. A field programmable array of this type is also described.

Abstract: A programmable logic device comprises a semiconductor with configurable circuitry, an input circuit for encrypted data to determine the configuration of the circuitry, decrypting circuitry responsive to a key value held in a non-volatile data store, and volatile storage circuitry for holding decrypted configuration data. Encrypting circuitry uses the same key value to encrypt configuration data and stores the encrypted configuration data for use in the programmable logic device.

Abstract: A peripheral controller is described which is suitable for connecting a selected one of a plurality of peripheral devices to a computer system. The peripheral controller comprises programmable bidirectional line driver/receiver devices which can be operated in an input only mode, an output only mode or a bidirectional mode and which can be set into an appropriate mode by configuration control data sent from the computer system to the peripheral controller. The peripheral controller also includes a re-configurable logic array which can be configured under the control of the configuration control data to implement a particular interface required for the selected peripheral device. This increases the efficiency of use of a peripheral interface.

Abstract: This invention relates to semiconductor integrated circuits which find utility in analogue systems. An integrated circuit of the invention comprises an array of configurable analogue cells each of which is capable of interconnection with other cells in the array by means of an interconnection network. Each of the cells can be selectively and individually selected by means of select signals and emanating from shift registers. When selected the cell may be configured with configuration data which both sets the cell to take up a particular electrical configuration by means of digital data and sets various programmable resistors and capacitors in the cells to particular values by means of analogue signals. The configuration data is held in a random access memory. Some of this data is converted to analogue form by means of a digital-to-analogue converter.

Abstract: A semiconductor integrated circuit comprising a configurable logic circuit array which may be programmed to configure a plurality of NAND-gates in the array to preform various and different logic functions. An additional logic circuit is provided at each discrete site or cell, and is controllable to cause the additional logic circuit and the logic circuit to implement either a simple NAND logic function or a simple LATCH logic function.

Abstract: Configurable semiconductor integrated circuits as-made each have a plurality of logic circuits formed at discrete sites. For each logic circuit, direct selectably conducting/non-conducting connection paths extend from its output to input of a first set of other logic circuits and to its inputs from outputs of a second set of other logic circuits. All of the sets for all of the logic circuits are each different. Other direct connection paths are selectably connectable to inputs and outputs of the logic circuits. Selection can be irreversible or reversible and involves coincident signal addressing of the sites and coded configuring of the paths at that site. Reversible selection can be via field effect transistors or bipolar transistors and can be at or near normal logic signal levels and speeds. Versatile configurable input/output arrangements are described also reconfigurable data processing systems using the reversible transistor provisions.

Abstract: A gated binary signal transmission circuit in a field effect semiconductor chip comprises a single signal-pass transistor connected between a bit signal input to one of its electrodes and a bit signal output from another of its electrodes. Its control electrode is connected for temporary energizations by switching circuitry operative only at prescribed intervals, the single signal-pass transistor being operative to pass signals between such energizations of its control electrode. Conduction of the single-pass transistor between energizations will persist, though with some decay, due to inherent capacitance and the control electrode being left "floating" between energizations.

Abstract: Selectable signal connection provisions are made for passing signals relative to logic circuitry of digital bipolar semiconductor integrated circuits. Each such provision has formed on the chip for each selectable signal connection, an active circuit element whose conduction state relative to signals concerned is controlled by applied circuit conditions. The conditions are selected by operative control circuitry responsive to a configuring or selection signal applied temporarily thereto for switching between stable states and thus determining the conduction state of the active circuit element.