Full-functionality back power protection (BPP) input/output (I/O) circuit with overvoltage protection including electrostatic discharge
AssigneeQUALCOMM Incorproated
InventorsWilson Jianbo Chen, Chiew-Guan Tan, Sreeker Dundigal
Life of this patent
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Abstract
An apparatus including: an overvoltage detector configured to generate an overvoltage indicating signal indicating whether a first voltage at an input/output (I/O) port is above an overvoltage threshold; a control circuit configured to generate a control signal based on the overvoltage indicating signal; a pseudo power source coupled to the I/O port and configured to provide a supply voltage for the control circuit; and a clamp circuit configured to generate a shunt current from the I/O port through an electrostatic discharge (ESD) protection diode, wherein the shunt current is enabled or disabled based on the control signal.
Claims26
An apparatus, comprising:
- an overvoltage detector including an input coupled to an input/output (I/O) port;
- a control circuit including an input coupled to an output of the overvoltage detector;
- a pseudo power source including an input coupled to the I/O port, and an output coupled to the control circuit;
- and
- a clamp circuit coupled between the I/O port and a voltage rail, through a diode, wherein the clamp circuit includes an input coupled to an output of the control circuit, wherein the pseudo power source comprises a first diode coupled in series with a capacitor between the I/O port and the voltage rail, wherein a node between the first diode and the capacitor is coupled to or serves as the output of the pseudo power source.
An apparatus, comprising:
- an overvoltage detector configured to generate an overvoltage indicating signal indicating whether a first voltage at an input/output (I/O) port is above an overvoltage threshold;
- a control circuit configured to generate a control signal based on the overvoltage indicating signal;
- a pseudo power source coupled to the I/O port and configured to provide a supply voltage for the control circuit;
- and
- a clamp circuit configured to generate a shunt current from the I/O port through an electrostatic discharge (ESD) protection diode, wherein the shunt current is enabled or disabled based on the control signal, wherein the control circuit comprises
- a latch configured to initialize the control signal to a first state based on the first voltage at the I/O port, and
- a circuit configured to flip the latch to set the control signal at a second state in response to the overvoltage indicating signal.
A method, comprising:
- generating an overvoltage indicating signal indicating whether a voltage at an input/output (I/O) port is above an overvoltage threshold;
- generating a control signal based on the overvoltage indicating signal;
- and
- enabling or disabling a shunting of current produced by the voltage from the I/O port to a voltage rail based on the control signal, wherein generating the control signal comprises
- initializing the control signal to a first state based on the voltage at the I/O port, and
- setting the control signal to a second state in response to the overvoltage indicating signal.
An apparatus, comprising:
- means for generating an overvoltage indicating signal indicating whether a voltage at an input/output (I/O) port is above an overvoltage threshold;
- means for generating a control signal based on the overvoltage indicating signal;
- and
- means for enabling or disabling a shunting of current produced by the voltage from the I/O port to a voltage rail based on the control signal, wherein the means for generating the control signal comprises
- means for initializing the control signal to a first state based on the voltage at the I/O port, and
- means for setting the control signal to a second state in response to the overvoltage indicating signal.
Dependencies are inferred from the claim text.