Abstract: An integrated circuit includes silicon layer (2) supported by a bottom oxide layer (3), a shallow trench oxide (4) in the shallow trench (30), and a polycrystalline silicon layer (5) on the shallow trench oxide. A deep trench oxide (25) extending from the shallow trench oxide to the bottom oxide layer electrically isolates a section (2A) of the silicon layer to prevent a silicon cone defect (22) on the silicon layer (2) from causing short-circuiting of the polycrystalline silicon layer (5) to a non-isolated section of the silicon layer. The polycrystalline silicon layer (5) can form a bottom plate of a poly/metal capacitor (20) and can also form a poly interconnect conductor (5A).

Abstract: A class AB folded cascode circuit includes a differential current follower having first and second cascode transistors with emitters connected to first and second input conductors. An input of a first current mirror is coupled to the first input conductor, and an input of a second current mirror is coupled to the second input conductor. Outputs of the second and first current mirrors are coupled to collectors of the first and second cascode transistors, respectively, and also to first and second outputs, respectively, of the differential current follower. A third current mirror converts a differential output current in the first and second output conductors to a corresponding single-ended output voltage on the second output conductor.

Abstract: An amplifier circuit includes an pair of input transistors, the drains of which are connected to emitters of first and second cascode transistors. First and second controlled current sources are connected to the emitters of the first and second cascode transistors, respectively, and third and fourth controlled current sources are connected to the collectors thereof. A bias circuit controls the 4 controlled current sources in response to the emitter voltage of a pair of input transistors of an output stage the inputs of which are connected to the drains of the first and second cascode transistors.

Abstract: An amplifying circuit which may be useful in a diamond buffer amplifier or operational amplifier includes an input transistor including an emitter, a collector, and a base coupled to receive an input voltage. An adjustable current source circuit is coupled between a first reference voltage and the emitter of the input transistor. A current source is coupled between a second reference voltage and the collector of the input transistor. An isolation resistor has a first terminal coupled to an output terminal of the adjustable current source circuit and a second terminal coupled to the emitter of the input transistor. A current follower circuit is coupled between the collector of the input transistor and an input terminal of the adjustable current source circuit. A feed-forward capacitor is coupled between the collector of the input transistor and the first terminal of the isolation resistor.

Abstract: An amplifying circuit which may be useful in a diamond buffer amplifier or operational amplifier includes an input transistor including an emitter, a collector, and a base coupled to receive an input voltage. An adjustable current source circuit is coupled between a first reference voltage and the emitter of the input transistor. A current source is coupled between a second reference voltage and the collector of the input transistor. An isolation resistor has a first terminal coupled to an output terminal of the adjustable current source circuit and a second terminal coupled to the emitter of the input transistor. A current follower circuit is coupled between the collector of the input transistor and an input terminal of the adjustable current source circuit. A feed-forward capacitor is coupled between the collector of the input transistor and the first terminal of the isolation resistor.

Abstract: Circuitry for preventing damage to bipolar transistors in integrated circuit amplifier circuitry during slew-limited operation includes first and second transistors, each having first, second, and third electrodes, a first one of the first and second electrodes of the first transistor being coupled to receive a first signal, and a first one of the first and second electrodes of the second transistor being coupled to receive a second signal.

Abstract: An amplifier (10) includes a first stage (4) including differentially coupled first (Q1) and second (Q2) input transistors and a controlled active load circuit (6). A second stage (8) includes differentially coupled third (Q5) and fourth (Q6) input transistors and a load circuit (Q7,8). A first output (2A) of the first stage (4) is coupled to a first input of the second stage (8), a second output (2B) of the first stage (4) being coupled to a second input of the second stage (8). A common mode feedback amplifier (12) has an input coupled to receive a common mode signal (3) from the second stage (8) for producing an amplified common mode signal (9) on a control input of the controlled active load circuit (6) to provide fast settling of an output (Vout) of the second stage without substantially increasing amplifier noise.

Abstract: A class AB folded cascode circuit includes a differential current follower having first and second cascode transistors with emitters connected to first and second input conductors. An input of a first current mirror is coupled to the first input conductor, and an input of a second current mirror is coupled to the second input conductor. Outputs of the second and first current mirrors are coupled to collectors of the first and second cascode transistors, respectively, and also to first and second outputs, respectively, of the differential current follower. A third current mirror converts a differential output current in the first and second output conductors to a corresponding single-ended output voltage on the second output conductor.

Abstract: An amplifier circuit includes an pair of input transistors, the drains of which are connected to emitters of first and second cascode transistors. First and second controlled current sources are connected to the emitters of the first and second cascode transistors, respectively, and third and fourth controlled current sources are connected to the collectors thereof. A bias circuit controls the 4 controlled current sources in response to the emitter voltage of a pair of input transistors of an output stage the inputs of which are connected to the drains of the first and second cascode transistors.

Abstract: Circuitry for preventing damage to bipolar transistors in integrated circuit amplifier circuitry during slew-limited operation includes first and second transistors, each having first, second, and third electrodes, a first one of the first and second electrodes of the first transistor being coupled to receive a first signal, and a first one of the first and second electrodes of the second transistor being coupled to receive a second signal.

Abstract: An amplifier (10) includes a first stage (4) including differentially coupled first (Q1) and second (Q2) input transistors and a controlled active load circuit (6). A second stage (8) includes differentially coupled third (Q5) and fourth (Q6) input transistors and a load circuit (Q7,8). A first output (2A) of the first stage (4) is coupled to a first input of the second stage (8), a second output (2B) of the first stage (4) being coupled to a second input of the second stage (8). A common mode feedback amplifier (12) has an input coupled to receive a common mode signal (3) from the second stage (8) for producing an amplified common mode signal (9) on a control input of the controlled active load circuit (6) to provide fast settling of an output (Vout) of the second stage without substantially increasing amplifier noise.