Abstract: A level shifter circuit includes a level shifter unit and a latch unit. The level shifter unit receives two complementary input signals and converts the voltage levels of two complementary input signals. The latch unit latches the state of two output nodes before the low voltage supply is turned off. On condition that the low voltage supply is off, the level shifter circuit avoids current drainage and ensures the voltage level of the output. The invention has the advantages of small circuit size and being easy to design.

Abstract: A programmable gain amplifier includes an OP amplifier, N decayed capacitor(s), (N+1) adjusting capacitor modules, switches, a switch control module, and a feedback switch. First terminals of adjusting capacitors of the capacitor modules are connected together. One capacitor module is connected to an input terminal of the OP amplifier, and neighboring two of the capacitor modules are connected together through one of the decayed capacitor(s). Each switch controlled by the switch control module has a common terminal connected to a second terminal of the capacitor so as to couple the capacitor to an input signal, a reference voltage, or an output terminal of the OP amplifier. The feedback switch is connected between the output terminal and the first input terminal, and turns on in a first phase. The adjusting capacitor can be connected to the output terminal to serve as the feedback capacitance through control of the switches in a second phase, which does not overlap with the first phase.

Abstract: A level shifter circuit includes a level shifter unit and a latch unit. The level shifter unit receives two complementary input signals and converts the voltage levels of two complementary input signals. The latch unit latches the state of two output nodes before the low voltage supply is turned off. On condition that the low voltage supply is off, the level shifter circuit avoids current drainage and ensures the voltage level of the output. The invention has the advantages of small circuit size and being easy to design.

Abstract: A voltage regulator circuit with a low quiescent current for generating a stable output voltage includes a standby mode controller for generating an enable signal according to a standby signal, a reference voltage generator for receiving an operation voltage and generating a reference voltage, an amplifier for receiving the reference voltage and the output voltage and generating an amplified voltage, and a switch unit for receiving the operation voltage and generating the output voltage at an output terminal. The enable signal is kept enabled when the standby signal is disabled, and the enable signal is periodically enabled when the standby signal is enabled. The amplifier works only when the enable signal is enabled. The switch unit is controlled by the enable signal, and is turned on only when the enable signal is enabled. So, the quiescent current of the voltage regulator circuit in the standby mode can be greatly reduced.

Abstract: A voltage regulator circuit with a low quiescent current for generating a stable output voltage includes a standby mode controller for generating an enable signal according to a standby signal, a reference voltage generator for receiving an operation voltage and generating a reference voltage, an amplifier for receiving the reference voltage and the output voltage and generating an amplified voltage, and a switch unit for receiving the operation voltage and generating the output voltage at an output terminal. The enable signal is kept enabled when the standby signal is disabled, and the enable signal is periodically enabled when the standby signal is enabled. The amplifier works only when the enable signal is enabled. The switch unit is controlled by the enable signal, and is turned on only when the enable signal is enabled. So, the quiescent current of the voltage regulator circuit in the standby mode can be greatly reduced.

Abstract: A charge-pump circuitry which receives an external voltage source to generate a target voltage is provided. The charge-pump circuitry comprises a voltage multiplier module and a voltage difference generating circuitry. Wherein, a first input terminal of the voltage multiplier module receives the external voltage source, and the voltage multiplier module generates a multiplied-voltage according to the external voltage source. The voltage potential of the multiplied-voltage is a predetermined times of the voltage potential of the external voltage source. The voltage difference generating circuitry generates a correcting voltage which is input to a second input terminal of the voltage multiplier module. The voltage potential of the correcting voltage is the potential difference between the target voltage and the multiplied-voltage.

Abstract: A charge-pump circuitry which receives an external voltage source to generate a target voltage is provided. The charge-pump circuitry comprises a voltage multiplier module and a voltage difference generating circuitry. Wherein, a first input terminal of the voltage multiplier module receives the external voltage source, and the voltage multiplier module generates a multiplied-voltage according to the external voltage source. The voltage potential of the multiplied-voltage is a predetermined times of the voltage potential of the external voltage source. The voltage difference generating circuitry generates a correcting voltage which is input to a second input terminal of the voltage multiplier module. The voltage potential of the correcting voltage is the potential difference between the target voltage and the multiplied-voltage.

Abstract: A voltage detector is disclosed, which has a resistor pair, a reference resistor, at least one transistor pair and a comparator. One resistor of the resistor pair is coupled between an input voltage and one of the transistor pair, and the other resistor is coupled between the input voltage and the reference resistor. The other transistor is coupled between the reference resistor and a ground voltage. Thus, a reference detection voltage and a voltage to be detected are generated. The comparator compares the reference detection voltage and the voltage to be detected to obtain a resulting output, wherein temperature effect can be eliminated by adjusting an area ratio of the transistors and an area ratio of the reference resistor to the resistor pair.

Abstract: A voltage reference circuit for generating various selectable voltage reference values with temperature independence is disclosed wherein a band-gap voltage reference circuit portion, that produces a temperature independent band-gap voltage reference V.sub.BG output, has a cascode current mirror circuit portion coupled thereto in such manner that a selectable voltage reference V.sub.REF is output with the temperature coefficient of the selected voltage reference canceled.