Cypress Semiconductor Corporation

Adrian Lin

A current-sink buffer is provided including a differential amplifier having a closed first-loop to provide a buffered output voltage, and a closed second-loop to sink transients in a load current of an output to ground. The first-loop includes a first transistor with a gate coupled to a reference-voltage, and a source coupled to a current-source; a second transistor with a gate coupled to a drain and the output, and a source coupled to the source of the first transistor; a first current-sink through which a drain of the first transistor is coupled to ground; and a second current-sink through which the second transistor drain is coupled to ground. The second-loop includes a third transistor with a grounded source, a drain coupled to the second transistor drain, and a gate coupled to the first transistor drain, and a capacitor coupled between the gate and drain of the third transistor.

Low-power fast-transient current-sink buffer

A floating-rail reference generator and method of operating the same are provided. Generally, the generator includes a tracking current source coupled in series with a current scaling resistor between an input voltage (V) and ground. The tracking current source is operable to receive a reference voltage and couple a tracking current through the resistor to produce a floating-rail reference voltage (V) at an output between the tracking current source and scaling resistor, wherein: V=((V−V)/k)·1/R·k·R, where Vis a desired constant potential difference between Vand V, k is a voltage scaling ratio, and R is a resistance of the current scaling resistor. In some embodiments, the tracking current source includes a transistor coupled between Vand the output, and controlled by a differential amplifier.

Low-power floating-rail reference generator

A low-dropout (LDO) regulator includes a voltage reference node and a one-stage differential amplifier coupled to the voltage reference node. The one-stage differential amplifier includes: a differential pair of NMOS transistors; a mirroring load comprising a first current source and a PMOS transistor; a direct feed-forward (DFF) loop formed by the PMOS transistor and its parasitic gate-to-drain capacitance during a load transient; and an indirect regulation feedback (IRF) loop formed by the differential pair of NMOS transistors, a resistor, and the PMOS transistor to provide direct current (DC) voltage regulation.

Low-power fast-transient low-dropout (LDO) regulator with direct feed-forward

Systems, methods, and devices generate multiple reference voltages. Methods include receiving, at a voltage regulator, a voltage from a voltage source, and generating, using the voltage regulator, a tracking current based on the received voltage, the tracking current having an amplitude that tracks changes in a voltage level of the voltage source. Methods also include generating, using the voltage regulator, a first reference voltage based on the tracking current, the first reference voltage being a designated voltage less than the voltage source and tracking changes in the voltage level of the voltage source, and generating, using the voltage regulator, a second reference voltage based on the received voltage, the second reference voltage being a fixed voltage.

Systems, methods, and devices for multi-reference voltage generators

A current-sink and method of using the same is provided for sinking transient load currents of a load coupled to a floating-rail. In one embodiment, the current-sink includes a latch system operable to receive a transient load current signal from the load and set a latch to apply a voltage to a gate of a current sinking switch. The current sinking switch includes a first source/drain (S/D) coupled to the floating-rail, and a second S/D coupled to ground, and is operable to sink the transient load current to provide a stable floating-rail voltage (V) on the floating-rail. Generally, the latch system further includes a dynamically biased comparator for comparing Vto a reference voltage and resetting the latch when a difference is less than a predetermined voltage. A dynamic bias circuit coupled to a latch output enables the comparator only while the transient load current is present.

Low-power fast-transient large current-sink with dynamic biasing

Systems, methods, and devices provide sampling for data converters. Methods include receiving a voltage from a voltage source, and identifying transconductance parameters and resistance parameters associated with a data converter, the transconductance parameters identifying a transconductance of the data converter. Methods also include selecting a resistor from a plurality of dynamically selectable resistors based on the resistance parameters, generating, using a programmable gain amplifier, a current based, at least in part, on the selected resistor and the received voltage, and providing the current to the data converter.

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Austin, TX, United States of America

Adrian Lin