A multi-stage amplifier includes a first stage comprising a first common-source amplifier, a first inductive load network comprising a serial connection of a first load resistor and a first load inductor, and a first source network configured to receive a first signal and output a first load signal, and a first inter-stage inductor configured to couple the first load signal to a second signal; and a second stage comprising a second common-source amplifier, a second inductive load network comprising a serial connection of a second load resistor and a second load inductor, and a second source network configured to receive the second signal and output a second load signal, and a second inter-stage inductor configured to couple the second load signal to a third signal, wherein the first load inductor and the second load inductor are laid out to enhance an inter-stage inductive coupling.

An automated testing system comprises a high side switch circuit coupled to an input/output (I/O) connection, a low side switch circuit coupled to the I/O connection, a high side force amplifier (HFA) coupled to the high side switch, a low side force amplifier (LFA) coupled to the low side switch, an adjusting circuit coupled to the HFA and the LFA, and a control circuit configured to change the adjusting circuit to change control of current at the I/O connection from one of the HFA or LFA to the other of the HFA or LFA.

Disclosed is an integrated circuit including a first bias current generating circuit. The first bias current generating circuit includes a first amplifier receiving a reference voltage and a first voltage and amplifying a difference between them to output a first output voltage, a first bias current generator receiving the first output voltage and outputting a first bias current in response to the first output voltage, a variable resistor receiving the first bias current and outputting the first voltage in response to the first bias current and a calibration code, a second bias current generator receiving the first output voltage and outputting a second bias current to a peripheral circuit in response to the first output voltage, and a third bias current generator receiving the first output voltage and outputting a third bias current to an external device through a first pad in response to the first output voltage.

Disclosed is an integrated circuit including a first bias current generating circuit. The first bias current generating circuit includes a first amplifier receiving a reference voltage and a first voltage and amplifying a difference between them to output a first output voltage, a first bias current generator receiving the first output voltage and outputting a first bias current in response to the first output voltage, a variable resistor receiving the first bias current and outputting the first voltage in response to the first bias current and a calibration code, a second bias current generator receiving the first output voltage and outputting a second bias current to a peripheral circuit in response to the first output voltage, and a third bias current generator receiving the first output voltage and outputting a third bias current to an external device through a first pad in response to the first output voltage.

A receiver front end having low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. A drain switch is provided between the drain terminals of input FETs to place the input FETs in parallel. This increases the g.sub.m of the input stage of the amplifier, thus improving the noise figure of the amplifier.

A receiver front end having low noise amplifiers (LNAs) is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured output FET can be turned on or off using the gate of the output FET. A first switch is provided that allows a connection to be either established or broken between the source terminal of the input FET of each LNA. A drain switch is provided between the drain terminals of input FETs to place the input FETs in parallel. This increases the g.sub.m of the input stage of the amplifier, thus improving the noise figure of the amplifier.

A semiconductor integrated circuit includes a first transmission power mode configured to transmit by a first power, and a second transmission power mode configured to transmit by a second power smaller than the first power, the semiconductor integrated circuit. The semiconductor integrated circuit includes a first transistor configured to receive and amplify a transmission signal in the second transmission power mode, and an attenuator including a resistor element and a switching element, provided between an output of the first transistor and an output terminal, configured to control attenuation of an output signal of the first transistor.

A semiconductor integrated circuit includes a first transmission power mode configured to transmit by a first power, and a second transmission power mode configured to transmit by a second power smaller than the first power, the semiconductor integrated circuit. The semiconductor integrated circuit includes a first transistor configured to receive and amplify a transmission signal in the second transmission power mode, and an attenuator including a resistor element and a switching element, provided between an output of the first transistor and an output terminal, configured to control attenuation of an output signal of the first transistor.

In certain aspects, a system includes an amplifying circuit having an input and an output, wherein the input of the amplifying circuit is coupled to a gate of a pass transistor of a low dropout (LDO) regulator. The system also includes a metal-oxide-semiconductor (MOS) capacitor coupled between the output of the amplifying circuit and the input of the amplifying circuit.

In certain aspects, a system includes an amplifying circuit having an input and an output, wherein the input of the amplifying circuit is coupled to a gate of a pass transistor of a low dropout (LDO) regulator. The system also includes a metal-oxide-semiconductor (MOS) capacitor coupled between the output of the amplifying circuit and the input of the amplifying circuit.