Image sensor including variable ramping slope and method
AssigneeSamsung Electronics Co., Ltd.
InventorKwang-Hee Lee
Life of this patent
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Abstract
An image sensor an image sensor includes an image sensing element which converts incident light into an analogue signal, a voltage generator which includes a variable resistor circuit and which generates a ramping voltage, where a slope of the ramping voltage is variable and corresponds a resistance value of the variable resistor circuit, a converter which converts a voltage of the analogue signal into a digital signal using the ramping voltage generated by the voltage generator, and a controller which controls the resistance value of the variable resistance circuit.
Claims11
An image sensor comprising:
- an image sensing element which converts incident light into an analogue signal;
- a voltage generator which includes a variable resistor circuit and which generates a ramping voltage, wherein a slope of the ramping voltage is variable and corresponds a resistance value of the variable resistor circuit;
- a converter which converts a voltage of the analogue signal into a digital signal using the ramping voltage generated by the voltage generator;
- and
- a controller which controls the resistance value of the variable resistance circuit;
- wherein a slope of the ramping voltage is linear, and wherein the voltage generator further includes an operational amplifier including an input connected to the variable resistance circuit, and a capacitor connected across the input and an output of the operational amplifier, and
- wherein the variable resistance circuit comprises:
- a nonvolatile storage unit which stores a first address in response to a first control signal;
- an address selector which selectively outputs the first address from the nonvolatile storage unit or a second address from the controller in response to a second control signal;
- a variable resistor chain coupled between an input terminal of the voltage generator and the input of the operational amplifier;
- and
- a resistance adjustor which sets a resistance value of the variable resistor chain in accordance with the output from the address selector.
An image sensor comprising:
- an image sensing element which converts incident light into an analogue signal;
- a voltage generator which includes a variable resistor circuit and which generates a ramping voltage, wherein a slope of the ramping voltage is variable and corresponds a resistance value of the variable resistor circuit;
- a converter which converts a voltage of the analogue signal into a digital signal using the ramping voltage generated by the voltage generator;
- and
- a controller which controls the resistance value of the variable resistance circuit;
- wherein a slope of the ramping voltage is linear, and wherein the voltage generator further includes an operational amplifier including an input connected to the variable resistance circuit, and a capacitor connected across the input and an output of the operational amplifier, and
- wherein the variable resistance circuit further comprises:
- a multiplexer connected between the variable resistor chain and the input of the operational amplifier;
- and
- a resistor connected between the input terminal of the voltage generator and the multiplexer;
- wherein the multiplexer selectively connects at least one of the resistor and the variable resistor chain to the input of the operational amplifier in response to an enabling signal from the controller.
A method of controlling the slope of a ramping voltage, comprising:
- receiving an address to adjust a resistance value;
- establishing the resistance value in correspondence with the address;
- generating a ramping voltage in correspondence with the established resistance value;
- determining whether the ramping voltage matches a target voltage;
- and
- storing the address when the ramping voltage matches the target voltage.
Dependencies are inferred from the claim text.