Abstract:
A random number generator including a random signal generator is provided to make other special offset elimination unnecessary and to be operable with a low voltage. A random signal generator comprises a noise source(110), a self-biased inverter(130) and an amplifying circuit(150). The noise source(110) generates irregular noise signals. The self-biased inverter gets self-biased by connecting an input terminal to an output terminal, and outputs a sensed noise signal by sensing the noise signal transmitted to the input terminal. The amplifying circuit amplifies the sensed noise signal and outputs a random signal whose logical high level and low level have irregular continuing time. The self-biased inverter includes a resistor connected between the input terminal and the output terminal.
Abstract:
A low voltage regulated cascade circuit and a CMOS analog circuit using the same are provided to maintain a high output resistance and a wide output voltage swing width at an operation voltage under one volt by maintaining a higher threshold voltage than the threshold voltage of NMOS transistors. A low voltage regulated cascade circuit includes a first MOS transistor(NM2), a second MOS transistor(NM1), a third MOS transistor(PM1), and a first current source(CS2). The first MOS transistor(NM2) of a first conductive type is connected between an output terminal and a first node. The second MOS transistor(NM1) of a first conductive type applies a bias voltage to a gate and is connected between the first node and a second power terminal. A third MOS transistor(PM1) of a second conductive type different from the first conductive type is connected between a first power terminal and a gate of the first MOS transistor(NM2). The first current source(CS2) is connected between a second power voltage and the gate of the first MOS transistor(NM2).
Abstract:
본 발명은 입력 버퍼를 공개한다. 이 회로는 전원전압과 패드사이에 연결되고 제어전압이 인가되는 게이트와 플로팅 웰 전압이 인가되는 기판을 가진 풀업 트랜지스터, 전원전압이 인가되는 게이트와 접지전압에 연결된 기판을 가지고 패드로 인가되는 신호를 전송하는 전송 트랜지스터, 전송 트랜지스터로 인가되는 신호를 버퍼하여 입력 신호를 발생하는 버퍼, 및 패드로 고전압이 인가되면 패드로 인가되는 전압을 제어전압 및 플로팅 웰 전압으로 발생하고, 패드로 고전압미만의 전압이 인가되면 제어전압으로 접지전압을, 플로팅 웰 전압으로 전원전압을 발생하는 제어회로로 구성되어 있다. 따라서, 패드가 플로팅 상태로 되는 경우에 패드를 전원전압 레벨로 풀업함으로써 외부의 장치의 패드에 연결된 입력 버퍼를 통한 누설 전류를 방지할 수 있으며, 패드로 고전압이 인가되는 경우에 풀업 트랜지스터가 오프됨으로써 풀업 트랜지스터가 고전압으로부터 보호될 수 있다.
Abstract:
PURPOSE: An input/output circuit of a semiconductor device is provided to perform a tolerant function during power-on/off. CONSTITUTION: A control signal generator unit(36) generates the first control signal of a power supply voltage level, the second control signal of a ground voltage level and the third control signal of a high voltage level during power-on when a high voltage is applied through a pad(42-1), and generates the first and the second control signals of the power supply voltage level and the third control signal of the high voltage level during power-off. An output buffer(38-1,...,38-n) comprises the first and the second pull-up transistor, the first and the second pull-down transistor, a pre-driver pulling up/down the pad when an output enable signal is activated and turning off the pull-up transistors and the pull-down transistors when the output enable signal is disabled, and the first tolerant and current flow prevention unit controlling a voltage difference between a gate and a source/drain of the pull-up transistors and the pull-down transistors and preventing current flow to the power supply voltage from the pad. And an input buffer(40-1,...,40-n) comprises the third and the fourth and the fifth pull-up transistors, the third pull-down transistor, and the second tolerant and current flow prevention unit controlling the voltage difference between a gate and a source/drain of the third and the fourth and the fifth pull-up transistor and the third pull-down transistor and preventing the current flow to the power supply voltage from the pad.
Abstract:
PURPOSE: An output buffer circuit for minimizing a variation of a slew rate due to a variation of PVT and a variation of load capacitance of an output terminal is provided to reduce the variation of slew rate and protect gate oxide layers of transistors from voltage higher than supply voltage. CONSTITUTION: A bias voltage generator(21) generates the first bias voltage(Nbias) and the second bias voltage(Pbias) by using reference voltage. The first slew rate control portion(23) controls a pull-up slew rate of an output driver(22) in response to output data(D) and the first bias voltage(Nbias). The second slew rate control portion(24) controls a pull-down slew rate in response to output data(D) and the second bias voltage(Pbias). The output driver(22) is formed with a pull-up driver(22a) and a pull-down driver(22b). The output driver(22) drives an output terminal(28) in response to an output signal(SC1) of the first slew rate control portion(23) and an output signal(SC2) of the second slew rate control portion(24). A slew rate compensation portion(25) compensates a variation of slew rate according to a variation of load capacitance of the output terminal(28). A high voltage protection portion(26) protects gate oxide layers of transistors from voltage higher than supply voltage.
Abstract:
슬루율 제어가 가능한 반도체 집적회로의 출력 구동회로가 개시되어 있다. 반도체 집적회로의 출력 구동회로는 프리 드라이버, 및 메인 드라이버를 구비한다. 프리 드라이버는 제 1 입력신호를 버퍼링하여 제 1 게이트 제어신호를 발생시켜 제 1 노드에 제공하고, 제 2 입력신호를 버퍼링하여 제 2 게이트 제어신호를 발생시켜 제 2 노드에 제공한다. 메인 드라이버는 제 1 게이트 제어신호 및 제 2 게이트 제어신호에 응답하여 출력신호를 발생시켜 출력노드에 제공한다. 출력신호가 상승 천이하는 동안 출력노드와 상기 제 1 노드 사이에 제 1 용량성 전류 경로가 형성되고, 출력신호가 하강 천이하는 동안 출력노드와 제 2 노드 사이에 제 2 용량성 전류 경로가 형성된다. 따라서, 출력 구동회로는 공정, 전압, 온도 등의 동작환경에 무관하게 일정한 슬루율을 가지는 출력신호를 발생시킬 수 있다.
Abstract:
An output buffer circuit for reducing a variation of the slew rate due to a variation of process, voltage and temperature (PVT) and the load capacitance of an output terminal, and semiconductor device including the same, include a first slew rate control circuit for pulling down the voltage of a pull-up signal in multiple stages in response to a first control signal, and a second slew rate control circuit for pulling up the voltage of a pull-down signal in multiple stages in response to a second control signal. A pull-up driver is provided for pulling up an output terminal in response to the pull-up signal, and a pull-down driver is provided for pulling down the output terminal in response to the pull-down signal. The first and second slew rate control circuits are controlled by bias voltages that are provided by a phase locked loop circuit and compensate for changes in PVT.
Abstract:
An input and output circuit of a semiconductor device is disclosed having an output buffer including first and second pull-up transistors connected in series between the power supply voltage and the pad, first and second pull-down transistors connected in series between the pad and the ground voltage, a pre-driver for pulling up or down a voltage of the pad when an output enable signal is enabled and for switching off the first and second pull-up transistors and the first and second pull-down transistors when the output enable signal is disabled, and a first circuit for adjusting voltage differences between respective gates and respective sources/drains of the first and second pull-up transistors and the first and second pull-down transistors to be below a predetermined voltage level in response to the first, second and third control signals under power on or power off conditions; and an input buffer including a transmission gate for transmitting an input signal applied to the pad to a first node in response to the first control signal, third, fourth and fifth pull-up transistors connected in series between the power supply voltage and a second node and having corresponding gates connected to a third node, the pad and the first node, respectively, a third pull-down transistor connected between the second node and the ground voltage and having a gate connected to the first node, a second circuit for adjusting voltage differences between respective gates and respective sources/drains of the third, fourth and fifth pull-up transistors and the third pull-down transistor to be below a predetermined voltage in response to the first and third control signals if the high voltage is applied to the pad under either power on or power off conditions.
Abstract:
저전압 레귤레이티드 캐스코드 회로를 개시한다. 본 발명의 회로는 본 발명의 목적을 달성하기 위하여 제1전원단자와 출력단자 사이에 연결된 제1전류원과, 출력단자와 제1노드 사이에 연결된 제1모스 트랜지스터와, 게이트에 바이어스 전압이 인가되고 제1노드와 제2전원단자 사이에 연결된 제2모스 트랜지스터와, 제1전원단자와 상기 제1모스 트랜지스터의 게이트 사이에 연결된 제3모스 트랜지스터와, 제1모스 트랜지스터의 게이트와 제2전원전압 사이에 연결된 제2전류원을 포함한다. 따라서, 1V 이하의 저전압에서도 높은 출력저항과 넓은 전압 스윙폭을 유지하면서도 안정된 동작특성을 유지할 수 있다.
Abstract:
PURPOSE: An output buffer circuit for reducing slew rate variation owing to variation of load capacitance of output terminal and PVT variation and semiconductor device having the same are provided to reduce slew rate variation owing to PVT variation and variation of load capacitance of an output terminal. CONSTITUTION: A pull-up driver(P6) pulls up an output terminal(41) in response to a pull-up signal, and a pull-down driver(N6) pulls down the output terminal in response to the pull-down signal. The first slew rate control circuit(271) makes a voltage level of the pull-up signal be lowered stepwise in response to the first control signal(PC). The second slew rate control circuit(272) makes a voltage level of the pull-down signal(NG) be increased stepwise in response to the second control signal(NC).