Abstract: A curvature corrected bandgap reference voltage circuit, the output voltage of which is substantially linear and independent of the operating temperature of the circuit. The circuit includes a voltage divider network comprised of a first resistor and a second resistor connected in series. A first compensating circuit provides a first, linear, operating temperature-dependent current, and a second compensating circuit provides a second, logarithmic, operating temperature-dependent current. The first current is supplied to the first resistor of said voltage divider network, while the second current is supplied to the second resistor of the voltage divider network.

Abstract: An improved low-dropout ("LDO") voltage regulator incorporates a transient response boost circuit which is added to the slew-rate limited node at the control terminal of the LDO voltage regulator output transistor and provides improved transient response performance to the application of various load current step stimuli while requiring no standby or quiescent current during zero output current load conditions. The transient boost circuit supplies current to the slew-rate limited node only upon demand and may be constructed as either a localized positive feedback loop or a number of switching devices which conduct current only during slew-rate conditions.

Abstract: A low drop-out regulator 16 includes an error amplifier 18 having a first input for receiving a reference voltage Vref, a second input, and an output, a pass element 22 having a control terminal coupled to the output of the error amplifier and a current path coupled between an input voltage Vin and an output terminal Vout, and a pair of resistors 24, 26 coupled in series between the output terminal Vout and ground. The second input of the error amplifier 18 coupled to a node B between the pair of resistors. The error amplifier provides an added pole/zero pair in the frequency response of the regulator.

Abstract: A bandgap circuit (16) for supplying a reference voltage includes a first current source (AI.sub.Vbe) supplying a current proportional to a base-emitter voltage, a second current source (BI.sub.PTAT) supplying a current proportional to absolute temperature, and a third current source (CI.sub.NL) supplying a non-linear current. First (R3), second (R2), and third (R1) resistors are coupled in series between a first node (c) and ground. The first current source is coupled to the first node. The second current source is coupled to a second node (a) between the first and second resistors. The third current source is coupled to a third node (b) between the second and third resistors. An output coupled to the first node supplies the reference voltage Vref. The bandgap circuit provides a low voltage reference with temperature compensation flexibility.

Abstract: A voltage regulator circuit includes: a first MOS transistor 12 coupled between a voltage supply line and an output node 44, the first MOS transistor 12 providing a stable voltage on the output node 44; a source follower 24 coupled to a gate of the first MOS transistor 12; an amplifier 38 coupled to a gate of the source follower 24 for controlling the response of the first MOS transistor 12; negative feedback circuitry coupled between the output node 44 and the amplifier 38, the feedback circuitry providing feedback to the amplifier 38; a current conveyer 46 coupled to the first MOS transistor 12; and positive feedback circuitry 26 coupled between the current conveyer 46 and the source follower 24.

Abstract: A circuit and method for sensing and limiting current. An output driving transistor (M1) is coupled between a circuit output terminal and a power supply terminal. A replicator circuit is formed in a cross-coupled quad configuration from bipolar transistors (Q11, Q12, Q13 and Q14) and is coupled to a second transistor (M2) which generals a voltage proportional to the current flowing in the output driving transistor (M1). The current sensing circuit generates an output current which is proportional to the current flowing in the output driving transistor multiplied by a ratio of the sizes of the second transistor and the output driving transistor. In a current limiting configuration, the output of the cross-coupled quad is used to reset a flip-flop (FF1) that drives the gate terminal of the output transistor (M1), thus shutting down the output transistor before it is damaged due to excess current. The circuitry of the invention may be applied to a high side driver or a low side driver output circuit.

Abstract: A circuit and method for sensing and limiting current. A resistor (R1) is used to generate a voltage (V1) proportional to the current flowing in an output transistor (M1). A comparator is formed in a cross coupled quad configuration from bipolar transistors (Q11, Q12, Q13 and Q14) and is coupled to the resistor (R1). When the current in the resistor (R1) generates a voltage in excess of a threshold voltage for the cross coupled quad circuit, the cross coupled quad generates an output indicating the threshold has been reached. In a current limiting configuration, the output of the cross coupled quad is used to reset a flip-flop (FF1) that drives the gate terminal of the output transistor (M1), thus shutting down the output transistor before it is damaged due to excess current. The threshold voltage that triggers the cross coupled quad is proportional-to-absolute-temperature.

Abstract: An amplifier circuit (10) is provided. The amplifier (10) includes an amplifier stage (14) coupled to an output stage (18). Output stage (18) comprises a sourcing circuit (20) and a sinking circuit (22). The current in sinking circuit (22) is approximately mirrored at low current in mirror circuit (34). At higher currents, resistor (36) maintains the current in mirror circuit (34) below the current in sinking circuit (22). A diode (38) diverts current to mirror circuit (34) to aid sinking circuit (22) in sinking current from a load (12). A current source (29) supplies current to sourcing circuit (20) and mirror circuit (34). A control signal output by amplifier stage (14) causes mirror circuit (34) to draw or not draw current from current source (29). If mirror circuit (34) draws current from current source (29), output stage (18) sinks current in sinking circuit (22). If mirror circuit (34) does not draw current from current source (29), output stage (18) sources current through sourcing circuit (20).

Abstract: An amplifier circuit (10) is provided. Amplifier (10) has an amplifier stage (14) that is coupled to control an output stage (18). Output stage (18) includes a sourcing circuit (20) and a sinking circuit (22). Output stage (18) also includes a mirror circuit (42) that is coupled to an output of amplifier stage (14). Output stage (18) also includes a current balancing circuit (30) coupled to mirroring circuit (42) and sourcing circuit (20). Mirroring circuit (42) draws current from balancing circuit (30) in response to a first predetermined output from amplifier stage (14) such that balancing circuit (30) causes an insignificant current to flow in sourcing circuit (20). Thus amplifier (10) operates to sink current from an external load (12). Alternatively, mirroring circuit (42) may draw an insignificant current from balancing circuit (30) in response to a second predetermined output of the amplifier stage (14). This causes a significant current flow in sourcing circuit (20).