The present invention is directed to perform fine low-voltage control without largely increasing the circuit layout area in a low-power consumption structure. In the case of shifting a region to a low-speed mode, a system controller outputs a request signal and an enable signal to a power switch controller and a low-power drive circuit, respectively, to turn off a power switch and to perform a control so that the voltage level of a virtual reference potential becomes about 0.2 V to about 0.3V. The region operates on voltages between a power supply voltage and a virtual reference potential, so that it is controlled in the low-speed mode.

Semiconductor Integrated Circuit Device

A programmable logic device (PLD) includes a delay circuit and a body-bias generator. The delay circuit has a delay configured to represent a delay of user circuit implement in the PLD. The body-bias generator is configured to adjust the body bias of a transistor within the user circuit. The body-bias generator adjusts the body bias of the transistor in response to a level derived from the signal propagation delay of the delay circuit.

Apparatus and Methods for Adjusting Performance of Integrated Circuits

A differential driver includes a switching module and first and second voltage controlled voltage sources. The switching module has a plurality of switches each controlled by an input signal, a first voltage input and a second voltage input, and a signal output. The first voltage controlled voltage source is connected to the first voltage input. The first voltage controlled voltage source has a low impedance. The second voltage controlled voltage source is connected to the second voltage input. The second voltage controlled voltage source also has a low impedance. The switching circuit outputs an output signal having an output voltage and current controlled by the first and second voltage controlled voltage sources. The output signal is based upon the input signal.

Voltage mode differential driver and method

In a power on reset (POR) circuit, when power is turned on, an output signal of an inverter attains an H level and an N channel MOS transistor is rendered conductive. The potential of an input node of the inverter becomes a potential of a power supply voltage divided by a conductive resistance value R1 of a P channel MOS transistor and a conductive resistance value R2 of an N channel MOS transistor. Assuming that the threshold voltage of the inverter is 0.8 V and R1:R2=2:3, then the power supply voltage Vres at the time when signal POR# inverts its level becomes 1.33 V. Thus, this POR circuit can reliably be utilized even in a product designed to operate with 1.5 V incorporating a MOS transistor having a threshold voltage of 0.8 V.

Power on reset circuit

A feedback enhanced triggering device for an electrostatic discharge protection circuit includes: a first inverter 30 b having an output coupled to an input of a second inverter 30 c , the second inverter 30 c having an output coupled to a control node for a discharge device 31 such as a transistor; a high side feedback transistor 34 coupled to the output of the first inverter 30 b , and having a control node coupled to the output of the second inverter 30 c ; and a low side feedback transistor 35 coupled to the output of the first inverter 30 b , and having a control node coupled to the output of the second inverter 30 c , wherein the feedback transistors 34 and 35 provide enhanced triggering for electrostatic discharge protection.

Electrostatic discharge protection circuit with feedback enhanced triggering

An electro-static-discharge (ESD) protection circuit is coupled between power and ground. It protects core circuits in a semiconductor chip. The ESD protection circuit is an active circuit that drives the gate of an n-channel clamp transistor. The clamp transistor shunts current from power to ground when its gate is driven high during an ESD event. A voltage divider generates a sense voltage that drives a first inverter. The sense voltage is normally much lower than the switch threshold of the first inverter. When an ESD voltage spike occurs, the sense voltage rises above the switch threshold, switching the output of the first inverter. A string of inverters is driven by the first inverter, with a final inverter driving the gate of the clamp transistor. An extending n-channel transistor drives the input of the final inverter low when the clamping transistor is on, extending the discharge time. A hysteresis p-channel transistor drives the output of the first inverter high, delaying turn-on of the clamp transistor. This increases the voltage required to trigger the protection circuit.

Active Vcc-to-Vss ESD clamp with hystersis for low supply chips

A differential amplifier has a wide common-mode input range since it uses two complementary amplifiers. One amplifier has a differential pair of n-channel transistors while the other amplifier has a differential pair of p-channel transistors. The input range is extended further by replacing the current mirror transistors with load resistors. The load resistors continue to supply current to the differential pair transistors even when the input is within a transistor-threshold of the power or ground rails. The current through the load resistors is mirrored to intermediate mirror transistors that have their gate connected to the resistor's terminal node. Current in the differential amplifiers is mirrored as if current-mirror transistors were present rather than the load transistors. The intermediate mirror transistors supply current to inverse-mirror transistors. Since the inverse mirror transistors are of the opposite type as the intermediate mirror transistors, the inverse mirror transistors continue to operate when the input voltage is in the extreme of the range that shuts off the intermediate mirror transistors. Outputs of the intermediate and inverse mirror transistors of the two amplifiers are connected together and buffered by a final stage.

Complementary differential amplifier with resistive loads for wide common-mode input range

A power-up-reset circuit draws zero standby current. Rather than use a voltage divider that always draws current, a capacitive-pullup divider is used as the first stage. The capacitive-pullup divider has a capacitor to power (Vcc) and n-channel series transistors to ground. A sensing node between the capacitor and n-channel series transistors is initially pulled high to Vcc as Vcc is ramped up. The n-channel transistors remain off until Vcc reaches about 1.5 volts. Then the n-channel transistors pull the sensing node quickly to ground, ending the reset pulse. The second stage has a capacitor to ground that initially holds a threshold node low. A p-channel transistor has a gate connected to the sensing node and charges up the capacitor when the sensing node falls to ground. A third stage is triggered to change state as the capacitor is charged up by the p-channel transistor. Then a Schmidt trigger toggles, as do downstream inverter stages. A feedback signal goes low, disabling the gate of a pulldown n-channel transistor in the second stage. This disables a power-to-ground current path.

Zero standby-current power-on reset circuit with Schmidt trigger sensing

A fail-safe circuit for a pair of differential input lines detects when one or both lines are open. Each line has a pull-up of a switched p-channel transistor in series with a resistor or another p-channel transistor that has its effective resistance controlled by a gate bias. The gate of the switched p-channel transistor is driven to ground when power is applied to the gate of a grounding n-channel transistor. When power is off, a p-channel connecting transistor charges the gate node from the differential input line when a positive voltage is applied to the input line, such as during a leakage test. Charging the gate node prevents the switched p-channel transistor from turning on, blocking a leakage current path through the pull-up. An N-well bias circuit can be added, which connects the N-well under p-channel transistors to power or the gate node or the input line.

Ke Wu

Papers

Active Vcc-to-Vss ESD clamp with hystersis for low supply chips

Complementary differential amplifier with resistive loads for wide common-mode input range

Zero standby-current power-on reset circuit with Schmidt trigger sensing

Fail-safe circuit with low input impedance using active-transistor differential-line terminators