Abstract: Apparatuses and methods for directional coupling are disclosed. In one embodiment, an apparatus includes a directional coupler, a termination impedance, a switch, and a control block. The directional coupler includes a power input terminal, a power output terminal, a couple terminal and a terminate terminal. The power input terminal can receive a radio frequency signal from a power amplifier, and the power output terminal can be electrically connected to a load. The switch has an ON state and an OFF state, and includes an input electrically connected to the terminate terminal and an output electrically connected to the termination impedance. The switch is configured to provide a relatively low impedance path between the input and the output when in the ON state and to provide a relatively high impedance path between the input and the output when in the OFF state. The control block can set the state of the switch.

Abstract: Apparatuses and methods for disabling well bias are disclosed. In one embodiment, an apparatus includes a complimentary metal oxide semiconductor (CMOS) switch having a gate, a drain, a source, and a well. The source and drain are formed in the well. The gate is formed adjacent the well between the source and drain, and the source is configured to receive a bias voltage from a power amplifier. The apparatus further includes a well bias control block for biasing the well voltage of the first switch and a disable circuit for disabling the well bias control block so as to prevent the well bias control block from biasing the well. The well bias control block can bias the well voltage of the first switch to at least two voltage levels.

Abstract: Apparatuses and methods for enabled switch detection are disclosed. In one embodiment, an apparatus includes a complimentary metal oxide semiconductor (CMOS) switch having a gate, a drain, a source, and a well. The source and drain are formed in the well, and the gate is formed adjacent the well between the source and drain. The source is configured to receive a radio frequency signal from a first power amplifier. The apparatus further includes a switch enable detect block configured to compare a signal indicative of the gate voltage of the first switch to a first reference signal and to generate an output comparison signal based at least partly on the comparison. The apparatus further includes a power amplifier bias control block configured to enable the first power amplifier based at least partly on the output comparison signal from the switch sense block.

Abstract: A prescaler (200) includes a first frequency divider (204, 206) configured to receive an input signal at an input frequency. The prescaler further includes a phase rotator (208) coupled to the first frequency divider to produce a plurality of signal phases in response to the input signal. A frequency control circuit (214) is configured as a one-hot decoder to select one signal phase of the plurality of signal phases. The one-hot decoder provides maximum speed of operation of the prescaler by eliminating decoding of the feedback signal.

Abstract: A power-on reset circuit for resetting the register values contained on an integrated circuit upon power-up of the integrated circuit. The power-on reset circuit can be implemented either internal or external to the integrated circuit. The power-on reset circuit generates a reset signal as long as the supply voltage is not in the operational range and maintains the reset signal for a certain time after the supply voltage has returned to its nominal value. The power-on reset circuit also provides accurate detection of a serious supply voltage drop and has low power consumption. The power-on reset circuit comprises a battery, a voltage-referenced switching circuit, a current source, a capacitor and a voltage buffer.