Abstract: A power supply has multiple power supply modules connected in parallel. Each power supply module has a power conversion circuit having an input coupled for receiving an input voltage. A resistor is serially coupled in an output of the power conversion circuit. A current limit amplifier has first and second inputs coupled to first and second terminals of the first resistor. A feedback amplifier has a first input coupled for receiving an output voltage of the power supply module, a second input coupled for receiving a reference signal, and an output coupled for providing a feedback signal to the power conversion circuit. A compensation resistor is coupled between an output of the current limit amplifier and the second input of the feedback amplifier for adjusting the reference signal to compensate for variation in output current of the power conversion circuit.

Abstract: A variable output power supply for use in a highly efficient linear amplification system includes an envelope detector having at least one input for receiving an input signal to be amplified. The envelope detector generates, as an output, a control signal that is representative of an envelope of the input signal. The variable output power supply further includes a controllable source that is coupled to the envelope detector. The controllable source generates an output voltage and/or current that is responsive to the control signal, such that the output of the variable output power supply dynamically changes as a function of the envelope of the input signal. When employed in a linear amplification system, the variable output power supply provides a supply voltage to a linear amplifier which can be dynamically varied in response to the envelope of the input signal so as to provide a substantially constant voltage supply headroom for the amplifier.

Abstract: A variable output power supply for use in a highly efficient linear amplification system includes an envelope detector having at least one input for receiving an input signal to be amplified. The envelope detector generates, as an output, a control signal that is representative of an envelope of the input signal. The variable output power supply further includes a controllable source that is coupled to the envelope detector. The controllable source generates an output voltage and/or current that is responsive to the control signal, such that the output of the variable output power supply dynamically changes as a function of the envelope of the input signal. When employed in a linear amplification system, the variable output power supply provides a supply voltage to a linear amplifier which can be dynamically varied in response to the envelope of the input signal so as to provide a substantially constant voltage supply headroom for the amplifier.

Abstract: The ESD (Equivalent Shottky Diode, or Emanuil Shvarts Diode) includes a transistor and a sensing circuit, which senses a voltage difference across the ESD. A driving circuit controls the operation of the transistor based on the sensed difference.

Abstract: An RF power amplifier network with a redundant power supply comprising a plurality of RF power amplifiers. Each RF power amplifier includes a power supply unit and an amplifier load. The power supply unit is adapted for receiving a primary input voltage Vin and producing a secondary output voltage Vout, and the power supply unit is further adapted for generating a power supply fail signal upon failure of the power supply unit. The network further includes a supply bus to which is connected each power supply unit of each RF power amplifier, and each amplifier load of each RF power amplifier. A switch associated with each of the power supply units is responsive to the fail signal for disconnecting the power supply unit from the bus in the event of failure of the power supply unit.

Abstract: The battery life of a portable radiotelephone is increased by providing a variable instead of a fixed value of collector-emitter current for the low noise transistor in the RF receiving stage. In particular, the collector current of the RF receiving stage is microprocessor controlled in inverse proportion to the strength of the received signal, an indication of which is advantageously taken from the normally provided "RSSI" output signal provided by the radiotelephone set's conventional IF chip. The microprocessor stores an indication of the correct amount of base current drive to be supplied to the RF transistor to determine its collector current for strong signal and weak signal conditions as well as monitoring collector current for varying base drive to compensate for temperature effects.