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US 9,520,840 B2Granted
Current limiter
AssigneeNXP B.V.
InventorsMattheus Johan Koerts, Fred Mostert, Fre Jorrit Jorritsma
Life of this patent
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Abstract
A current limiter for Class-D amplifiers measures and stores a position of an over-current event. By comparing the stored position, output signals can be selectively inverted. As a result, the Class-D amplifier remains in a defined modulation scheme even during period of current limiting.
Claims17
A current limiter for a class D amplifier, the current limiter comprising:
- an over-current protection (OCP) block coupled to both a first side and a second side of the class D amplifier, wherein the OCP block further comprises:
- a plurality of over-current detecting (OCD) inputs;
- a plurality of OCP count blocks coupled to the plurality of OCD inputs;
- an OCP minimum position block coupled to the plurality of OCP count blocks;
- and
- a plurality of comparators coupled to the OCP minimum position block and configured to receive a plurality of running event position signals.
3 more elements
A method of limiting currents for a class D amplifier, the method comprising:
- detecting an over-current event;
- storing a position of the over-current event as an OCD position;
- comparing the stored OCD position to a PWM carrier position;
- and
- inverting a PWM signal when the PWM carrier position is equal to the stored OCD position.
2 more elements
Dependencies are inferred from the claim text.