Lg Semicon Co., Ltd.

Youn-Cherl Shin

Dae-Jeong Kim

Dae Jeong Kim

A start-up circuit for a reference voltage generator which restarts a reference voltage generating circuit when a reference voltage drops below a predetermined level due to noises or change of a power supply voltage. The start-up circuit according to the present invention includes a reference voltage generating unit operated by an input signal and generating a reference voltage in accordance with a power supply voltage, a reference voltage sensing unit determining whether an output signal from the reference voltage generating unit is lower than a predetermined voltage level, and a start-up circuit unit determining an initial operation of the reference voltage generating unit in accordance with a reset signal and supplying the input signal to restart the reference voltage generating unit in accordance with an output signal from the reference voltage sensing unit.

Start-up circuit for voltage reference generator

An improved substrate voltage (VBB) generation circuit is disclosed. The circuit reduces variations in VBB (.DELTA.VBB) caused by variations (.DELTA.VCC) in a system voltage (VCC) by making a threshold voltage (Vt) of a logic element, e.g., an inverter of in a buffer, more sensitive to .DELTA.VCC. In contrast, the conventional art had attempted to reduce .DELTA.VBB by making the Vt of the logic element less sensitive to .DELTA.VCC. Two features of the improved logic element of the circuit contribute to the reduction of .DELTA.VBB. These features are: adopting an opposite channel ratio arrangement versus the conventional art; and incorporating additional active resistors.

Substrate voltage generation circuit

An improved current detection start-up circuit for a reference voltage circuit which restarts a reference voltage circuit when a reference voltage drops by a predetermined level, i.e., turns off, due to noise or a variation of a system voltage. The circuit includes: a current detection circuit for detecting the current being applied to a reference voltage circuit; and a start-up circuit for starting the reference voltage circuit when the current detected by the current detection circuit is below a predetermined level.

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Bucheon, South Korea

Youn-Cherl Shin