Led driver with comprehensive fault protections
AssigneeDialog Semiconductor GmbH
InventorsEnzhu Liang, Yuwen Wang, Ming Gu
Life of this patent
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Abstract
The embodiments disclosed herein describe a set of fault detection circuits for LED circuits in an LED channel. A first fault detection circuit is configured to detect a short fault across one or more LEDs. A second fault detection circuit is configured to detect an open fault across an LED. A third fault detection circuit is configured to detect a short across an LED channel transistor. A fourth fault detection circuit is configured to detect an LED channel sense resistor open fault. A fifth fault detection circuit is configured to detect if the LED channel is being intentionally unused. These fault detect circuits can be implemented in a fault detection integrated circuit coupled to the LED channel.
Claims20
An LED fault detection circuit configured to detect one or more faults of an LED channel comprising one or more LEDs coupled to a drain node of a transistor and a resistor coupled to a source node of the transistor, the circuit comprising:
- a first fault detection circuit configured to detect a short fault across one or more of the LEDs, the first fault detection circuit coupled to the drain node of the transistor;
- a second fault detection circuit coupled to a source node of the transistor and configured to:
- when the LED fault detection circuit is operating in an operating mode, detect an open fault within the one or more LEDs;
- and
- when the LED fault detection circuit is operating in a calibration mode, detect a short fault across the resistor;
- and
- a third fault detection circuit configured to detection a short fault across the drain node and the source node of the transistor, the third fault detection circuit coupled to the gate node of the transistor.
An LED fault detection integrated circuit configured to detect faults of an LED channel, the integrated circuit comprising:
- a first set of one or more fault detection circuits coupled to a source node of an LED channel transistor and configured to detect one or more LED channel faults when the integrated circuit is configured in a calibration mode;
- and
- a second set of one or more fault detection circuits configured to detect one or more LED channel faults when the integrated circuit is configured in an operating mode, at least one of the second set of fault detection circuits coupled to one of a drain node, a gate node, and a source node of the LED channel transistor;
- wherein a fault detection circuit of the first set of fault detection circuit and a fault detection circuit of the second set of fault detection circuits comprises the same fault detection circuit.
Dependencies are inferred from the claim text.