Abstract:
The integrated circuit includes a power driving device, and a pilot device for sensing current through the power driving device. The pilot device includes a composite pilot having a plurality of series connected transistors and which is at least active while the power driving device is in a linear mode, and a secondary pilot which is active while the power driving device is in a saturation mode. Also, a control circuit activates the secondary pilot.
Abstract:
A power supply switching circuit arrangement is configured to provide a relatively smooth (low noise) power supply switch-over during the transition between active and quiescent modes. Complementary inputs of an operational amplifier are selective coupled to feedback paths to the amplifier and the power supply switching circuit arrangement, so as to bias a switching transistor during system active mode at a value that is just slightly below the turn-on voltage of the transistor. This means that turning on the switching transistor for the purpose of providing quiescent mode powering of the utility device requires only a small transition in control voltage from an active mode nullalmost turned-onnull level.
Abstract:
The integrated circuit includes a power FET for generating an output voltage, a pilot FET for sensing current through the power driving device and generating a reference voltage, and an amplifier circuit for comparing the reference voltage of the pilot device with the output voltage of the power driving device. The amplifier circuit includes a differential pair of matched bipolar junction transistors (BJTs) having a common base. A first BJT of the differential pair being diode-connected. The amplifier circuit controls the gates of the power FET and the pilot FET.