Flexible hook switch driver circuit
AssigneeIntegration Associates Inc.
InventorsWayne Holcombe, Vitor Pereira
Life of this patent
Estimating the term…
Abstract
Disclosed is a switch driver circuit is shown where the circuit can control current driven devices and drive devices across a capacitive barrier. A mode control signal determines whether the circuit is in a current mode or a capacitive mode. In current mode, the circuit provides a current output signal at an output of the circuit in response to a subject signal, such as an ON switch control signal for a hook switch application. In capacitive mode, the circuit provides a clocked output signal at the output of the circuit in response to the subject signal, such that the clocked output signal can pass across a capacitive isolation barrier.
Claims13
A switch driver circuit, the circuit comprising:
- a first output driver having an input and an output coupled to a first output pin of the circuit;
- a first current source having an enable input and an output coupled to the first output pin, where the first current source is configured to source current from a power supply to the output responsive to the enable input;
- a logic circuit having a first input for receiving a subject signal, a second input for receiving a clock signal, a third input for receiving a mode control signal, a current control output coupled to the enable input of the first current source, and a first output coupled to the input of the first output driver,
- where the logic circuit is configured to respond to a first state of the control mode signal by enabling the subject signal to modulate the clock signal for output to the first output of the logic circuit and disable the first current source through the current control output, and
- where the logic circuit is further configured to respond to a second state of the control mode signal by enabling the subject signal to control the first current source through the current control output, disable the clock signal, and output the subject signal through the first output of the logic circuit.
A method for passing a subject signal across different types of isolation barriers, the method comprising the steps of:
- providing a first output for interfacing with the isolation barrier;
- receiving a mode control signal, a subject signal, and a clock signal;
- responsive to a first state of the mode control signal, modulating the clock signal with the subject signal in order to drive the first output;
- responsive to a second state of the mode control signal, sourcing current to the first output responsive to the subject signal and driving the first output with the subject signal.
An apparatus for passing a subject signal across different types of isolation barriers, the apparatus comprising:
- first output means for interfacing with the isolation barrier;
- means for sourcing current to the first output means under control of a current control signal;
- means for receiving a mode control signal, a subject signal, and a clock signal and, responsive to a first state of the mode control signal, modulate the clock signal with the subject signal in order to drive the first output means and, responsive to a second state of the mode control signal, generate the current control signal responsive to the subject signal and driving the first output with the subject signal.
Dependencies are inferred from the claim text.