摘要:
Voltage regulators are exposed to extreme amounts of voltage over short periods of time during an electrostatic discharge (ESD) event. Shunt regulators require protection from ESD events. Capacitors are passive devices that allow current flow when not in a steady-state condition. An apparatus and method compensates for the extreme voltages inherent in ESD events. By providing capacitance across the gate-drain junction of the shunt device in combination with a gate resistor, a voltage can be applied to the gate of the active device upon commencement of an ESD event, and cause the active device to “turn on” The “turned on” active device provides a pathway for the excess voltage from the ESD event to follow and discharge so as to avoid catastrophic failures.
摘要:
A method and apparatus provide for improved crowbar protection in a shunt regulator circuit including a shunt device. An over-temperature protection circuit may be combined with a fast-crowbar protection circuit such that maximum protection from damaging thermal energy is provided to a shunt device. The fast-crowbar protection circuit estimates the thermal energy in the shunt device based upon an integration method. By integrating a measured power over time the rise in temperature can be estimated such that the crowbar protection is enabled before the thermal energy can damage the shunt device. The integration method can be approximated using a piece-wise linear approximation such that the estimation circuitry can be simplified. A series of comparators and timing/delay circuits are employed to measure a current level in the shunt device over a given duration. The timing/delay circuits have memory such that heat build up and heat dissipation are modeled.
摘要:
Disclosed herein is new and improved system and method for supporting radiation shields. The system may include a first frame subassembly, a second frame assembly, and a quick disconnect. The first frame sub assembly may include an upper partial ring support, a lower partial ring support, and a plurality of vertical supports. The second frame sub assembly may include an upper partial ring support, a lower partial ring support, and a plurality of vertical supports. The second frame subassembly may have a ring hole. The quick disconnect may include a plug and a bolt. The plug may be permanently affixed to the first frame subassembly, and the bolt may be configured to pass through the ring hole and the plug hole in order to removably secure the first frame subassembly to the second frame subassembly.
摘要:
A cache server receives content and an instruction indicating an event associated with the content that causes a processor to invoke a call out to an adjunct device. The instruction further indicates an operation that the adjunct device is to perform. The cache server detects the event associated with the content, halts a flow of the content in response to detecting the event associated with the content, passes via the call out the content to the adjunct device to perform the operation, receives from the adjunct device a response and resulting data from the operation, and performs an additional operation on the resulting data based on the response from the adjunct device.
摘要:
A method for providing thermostatic temperature control in an integrated circuit is provided that includes internally heating the integrated circuit until the integrated circuit reaches an elevated temperature and holding the integrated circuit at the elevated temperature. For a particular embodiment, a temperature-dependent parameter of a temperature-sensitive block is tested while the integrated circuit is held at the elevated temperature.
摘要:
An apparatus and method is arranged to dynamically adjust a pulse width (e.g., off-time pulse) associated with a switching device in a converter such as a buck converter, a boost converter, or a buck-boost regulator. A one-shot circuit is configured to dynamically initiate a pulse cycle for the switching converter when the output voltage collapses to a level that is related to a monitored inductor current in the converter. By changing the start time associated with the one-shot circuit, the pulse-width (e.g., off-time pulse) associated with the switching device is varied. In one example, the one-shot circuit is triggered when the inductor current is sensed as decaying below a threshold. The one-shot circuit can be further arranged to have another pulse-width (e.g., on-time pulse) that is adjusted for phase alignment with a reference frequency using a PLL circuit.
摘要:
A safety circuit monitors a charging signal supplied by a charging circuit for charging a battery. Damage to the battery may occur when the voltage at the input terminal of the battery rises above the safe level for the battery. A voltage drop across a coupling circuit is used to generate an activation signal. The activation signal causes a power amplifier to lower the voltage of the charging signal before the charging signal can drive the inductances associated with the battery input terminal and leads to the point where damage to the battery may occur.
摘要:
An apparatus and method is directed to a thermal wake-up circuit and a thermal sensor that are utilized by another circuit. The thermal wake-up circuit monitors a temperature associated with the other circuit. The thermal sensor is activated by the thermal wake-up circuit when the temperature exceeds a first threshold level. The thermal sensor is deactivated by the thermal wake-up circuit when the temperature is below the first threshold level. In one embodiment, addition thermal sensors may be activated and deactivated by the thermal wake-up circuit. The thermal sensor and additional thermal sensors may be used to activate protection circuitry or to shut down the other circuit. Power consumption by the thermal sensor is minimized by maintaining the thermal sensor inactive until activated by the thermal wake-up circuit.
摘要:
The invention is directed towards a charging circuit for charging a cell that may be deeply discharged. A primary charging circuit charges the cell when the cell is not deeply discharged. A deeply discharged charging circuit charges the cell when the cell is deeply discharged. Determining when the cell is deeply discharged includes determining when the voltage of the cell is above, below, or equal to a predetermined threshold. According to one embodiment of the invention, the predetermined threshold is 2V. When the cell voltage is below a predetermined threshold voltage, which according to one embodiment is 0.5V, a low-voltage charging path is used to charge the cell.