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US 10,386,875 B2Granted
Bandgap reference circuit and sensor chip using the same
AssigneePixart Imaging Inc.
InventorsKok-Siang Tan, Wai-Lian Teo
Life of this patent
Estimating the term…
Abstract
A bandgap reference circuit including a clamp circuit is provided. The bandgap reference circuit performs the calibration only for one time in a normal mode to store a control code of a reference generator of the clamp circuit. In a suspend mode, the control code is used for controlling the reference generator to cause the clamp circuit to provide a desired source voltage, and a bandgap reference voltage source is shut down to reduce the power consumption.
Claims17
A sensor chip, comprising:
- a reference generator configured to provide a reference voltage;
- a clamp circuit, electrically coupled to the reference generator, and configured to receive the reference voltage and hold a source voltage;
- a regulator;
- a bandgap reference voltage source configured to provide a bandgap voltage in a normal mode;
- a multiplexer electrically coupled between the reference generator and the regulator;
- and
- a digital core configured to control the regulator and the multiplexer, wherein
- in a suspend mode, the digital core is configured to control the multiplexer to connect the reference voltage to the regulator, and the regulator is powered off,
- an LDO mode is entered when the digital core receives a rising edge or a falling edge of an external clock signal in the suspend mode, and the digital core is configured to power on the regulator to provide the source voltage in the LDO mode, and
- the bandgap reference voltage source is powered off in the suspend mode and the LDO mode.
7 more elements
A sensor chip, comprising:
- a reference generator configured to provide a reference voltage;
- a bandgap reference voltage source configured to provide a bandgap voltage;
- a regulator configured to provide a source voltage;
- a switching element coupled between the reference generator, the bandgap reference voltage source and the regulator,
- a clock generator configured to generate a reference clock signal;
- a counter configured to count rising edges or falling edges of the reference clock signal;
- and
- a digital core configured to control a switching function of the switching element and ON/OFF of the regulator, wherein
- in a normal mode, the switching element is controlled to connect the bandgap voltage to the regulator to generate the source voltage, and
- in a suspend mode, the switching element is controlled to connect the reference voltage to the regulator, and the bandgap reference voltage source is powered off when the regulator is powered off in the suspend mode, wherein the regulator is powered on to generate the source voltage when the digital core receives a communication event, and when the communication event is over and the counter counts to a predetermined number after the regulator is powered on, the digital core is configured to power off the regulator.
7 more elements
A sensor chip, comprising:
- a reference generator configured to provide a reference voltage;
- a clamp circuit, electrically coupled to the reference generator, and configured to receive the reference voltage and hold a source voltage;
- a regulator;
- a multiplexer electrically coupled between the reference generator and the regulator;
- a clock generator configured to generate a reference clock signal;
- and
- a digital core configured to control the regulator and the multiplexer, wherein
- in a suspend mode, the digital core is configured to control the multiplexer to connect the reference voltage to the regulator, and the regulator is powered off,
- an LDO mode is entered when the digital core receives a rising edge or a falling edge of an external clock signal in the suspend mode, and the digital core is configured to power on the regulator to provide the source voltage in the LDO mode, and
- in the LDO mode, when the external clock signal does not have the rising edge or the falling edge and the reference clock signal has a level change, the digital core is configured to power off the regulator to return to the suspend mode.
7 more elements
Dependencies are inferred from the claim text.