Back to results
US 10,298,040 B2Granted
Timer-based thermal protection for power components of a switch mode power supply
AssigneeContinental Automotive Systems, Inc.
InventorsMikhail Zarkhin, Alfons Fisch
Life of this patent
Estimating the term…
Abstract
The maximum time that external components of a switch mode power supply over-conduct is determined by an actual ambient temperature at which the devices are operating before they are turned on. Their operation time is thus extended when temperatures are low and decreased when temperatures are high.
Claims20
A switch-mode power supply comprising:
- a transistor, configured to provide current to a load from a battery having an output voltage, the output voltage from the battery changing responsive to load applied to the battery through the transistor, the transistor having an input node, which is coupled to the battery, an output node that is coupled to the load and a control node, wherein signals applied to the control node determine whether the transistor is on and conductive or, off and non-conductive;
- a processor having a control input and an output coupled to the control node of the transistor, the processor being configured to switch the transistor on and off and thereby control the transistor to provide current to the load, an output voltage at the output node of the transistor provided to the load being independent of an input voltage at the input node of the transistor from the battery but dependent on an amount of current flowing through the transistor from the battery, the processor additionally configured to shut off the transistor responsive to an inhibit signal received by the processor at the processor's control input;
- a thermal protection circuit coupled to the processor's control input, the thermal protection circuit comprising an ambient temperature sensor, a counter and a comparator, the thermal protection circuit being configured to provide a the inhibit signal to the processor responsive to:
- an ambient temperature as determined by the ambient temperature sensor;
- the output voltage of the battery;
- and
- an amount of time that the transistor is on and providing current to the load.
4 more elements
A method of protecting external power components of a switch mode power supply from thermal damage, the method comprising:
- determining an ambient temperature in real time;
- determining a maximum length of time to permit current to flow through the external power components using the ambient temperature;
- providing current to a load through the external power components and, starting a timer when a voltage of a battery, to which the external power components are coupled, falls below a predetermined voltage level;
- comparing an elapsed time as measured by the timer to the maximum length of time determined from the ambient temperature;
- and
- shutting off current to the load through the external power components when the elapsed time equals or exceeds the maximum length of time determined from the ambient temperature.
3 more elements
A switch-mode power supply comprising:
- a transistor configured to provide current to a load from a battery having an output voltage, the output voltage from the battery changing responsive to load applied to the battery through the transistor, the transistor having a first node, which is coupled to the battery, a second node that is coupled to the load and a control node, wherein a voltage applied to the control node at least partly determines whether the transistor is on and conductive or off and non-conductive;
- a processor having a control input and an output coupled to the control node of the transistor, the processor being configured to switch the transistor on and off and thereby control the transistor to provide current to the load, the processor additionally configured to shut off the transistor responsive to an inhibit signal received by the processor at the processor's control input;
- a thermal protection circuit coupled to the processor's control input, the thermal protection circuit comprising an ambient temperature sensor, a counter and a first comparator, the thermal protection circuit being configured to provide the inhibit signal to the processor responsive to:
- an ambient temperature as determined by the ambient temperature sensor;
- the battery output voltage;
- and
- the amount of time that the transistor is on and providing current to the load.
4 more elements
Dependencies are inferred from the claim text.