Abstract: The voltage regulator circuit contains a MOS transistor 12 connected between a voltage supply line 22 and an output line 30. The MOS transistor 12 provides a stable voltage on the output line 30 independent of voltage transients on the voltage supply line 22 and independent of current transients on the output line 30. An amplifier 14 coupled to the MOS transistor 12 controls the response of the MOS transistor 12. Feedback circuitry connected between the output line 30 and the amplifier 14 provides feedback to the amplifier 14. A voltage source 16 provides the reference for amplifier 14.

Abstract: A programmable mixed-mode circuit (180) has both digital (215,217) and analog (120,120',120") circuit portions. The digital portion (215,217) is provided by programmable digital logic. The analog portion (120,120',120") has a variety of analog circuits, including voltage references (218), high-speed comparators (208,209) and circuits (80) that are selectively configurable to provide operational amplifier or comparator functions. The analog circuits (122-125) are interconnected by programmable switch elements (128-131,160-167) so that the connection of the analog circuits to one another, to input or output pins (A0-A3,B0-B3,C0-C3) and to the digital circuitry (215,217) can be programmed.

Abstract: A non-linear transmission line terminator (10) is provided in which voltages appearing on a transmission line are sensed. If the voltage level sensed is equal to a predetermined voltage, the non-linear transmission line terminator (10) couples a reference voltage to the transmission line. If the sensed voltage is less than the predetermined voltage, the non-linear transmission line terminator (10) delivers current to the transmission line having a magnitude related non-linearly to the sensed voltage.

Abstract: A method and apparatus for a circuit physically realizing a virtual ground function producing a virtual ground voltage halfway between the supply and common voltages and having improved accuracy and stability is described. A stable bias current source is coupled to a precision resistor voltage divider network, which is used as a voltage reference generator to produce a virtual ground voltage of a precise value. This reference voltage is coupled to an operational amplifier configured in a unity gain configuration. The circuit thus created offers numerous advantages over the virtual ground circuits in use in the prior art. An integrated circuit implementing this circuit is described, and alternative packaging embodiments are disclosed. Other embodiments are also disclosed.

Abstract: An integrated circuit device (10) has an operational amplifier (12) and a charge pump (14) for creating a negative voltage level -Vcc. The operational amplifier (12) preferably has various sub-components. In particular, a bias generator (36) is included and connected to a neutral voltage level (31) isolated from the negative voltage level and providing current for operational amplifier (12). An input stage (38) has inputs (16 and 18) for receiving two input signals and maintains the input signals in a balanced signal path. A conversion circuitry (40) receives the input signals and creates a single differential signal eliminating noise received in the input stage (38). An output stage prepares this single differential signal for transfer out of the operational amplifier (12).

Abstract: A method and apparatus for a circuit physically realizing a virtual ground function and having improved accuracy and stability is described. A stable bias current source is coupled to a bandgap reference generator and resistances to produce a virtual ground voltage of a precise value, this voltage is then coupled to an operational amplifier configured in a unity gain configuration. The circuit thus created offers numerous advantages over the virtual ground circuits in use in the prior art. An integrated circuit implementing this circuit is described, and alternative packaging embodiments are disclosed. Other embodiments are also disclosed.