Semiconductor Components Industries, LLC

Catalyst Semiconductor, Inc.

Adrian Macarie Tache

Radu H Iacob

Cornel D Stanescu

Adam Peter Cosmin

Andrei Enache

Horia Profeta

Anca Mihaela Dragan

Sorin Stefan Georgescu

George Smarandoiu

A Peter Cosmin

Alina I Negut

Sabin A Eftimie

According to an aspect, an auto-zero amplifier includes a main amplifier, a secondary amplifier connected to the main amplifier, a plurality of switching including a first switch and a second switch, and a leakage control circuit.

Auto-zero amplifier for reducing output voltage drift over time

Circuits and techniques for buffering a digital signal are disclosed. The circuits and techniques allow a digital buffer circuit to accommodate a range of output voltages while maintaining a delay between input and output that is suitable for digital communications. The disclosed circuits and techniques utilize a combination of low voltage switches and high voltage switches. The low voltage switches dominate the buffering process when the buffer drives external circuitry (e.g., a communications bus) having a low voltage then, and the high voltage switches dominate the buffering process when the buffer drives external circuitry having a high voltage. The high voltage and low voltage switches configure themselves automatically based on an operating condition determined by the voltage level of the output with respect to the voltage level of the input.

Digital buffer circuit

A low-dropout (LDO) regulator includes a voltage reference circuit to provide a reference voltage, a pass device including an input terminal coupled to a voltage input, an output terminal to provide an output voltage and a control terminal, and an error amplifier including a first amplifier input for receiving the reference voltage, a second amplifier input, an amplifier output coupled to the control terminal of the pass device. Additionally, the LDO regulator includes a feedback circuit including a feedback input coupled to the output terminal of the pass device and a feedback output coupled to the second amplifier input to provide a feedback signal. The LDO regulator further includes a control circuit including a non-volatile memory to store configuration data to control operation of the voltage reference circuit, the pass device, the error amplifier, and the feedback circuit to produce the output voltage.

Programmable low-dropout regulator and methods therefor

A non-volatile memory (NVM) system includes a set of NVM cells, each including: a NVM transistor; an access transistor coupling the NVM transistor to a corresponding bit line; and a source select transistor coupling the NVM transistor to a common source. The NVM cells are written by a two-phase operation that includes an erase phase and a program phase. A common set of bit line voltages are applied to the bit lines during both the erase and programming phases. The access transistors are turned on and the source select transistors are turned off during the erase and programming phases. A first control voltage is applied to the control gates of the NVM transistors during the erase phase, and a second control voltage is applied to the control gates of the NVM transistors during the program phase. Under these conditions, the average required number of Fowler-Nordheim tunneling operations is reduced.

Non-volatile memory with high reliability

A digital potentiometer is disclosed that includes first, second, and third signal terminals. A chain of series-connected impedance elements with multiple tap points is connected between the first and second signal terminals. A plurality of first switching devices are each connected to a respective one of the multiple tap points and to an internal wiper node. A configurable output stage is connected between the internal wiper node and the third signal terminal. The configurable output stage includes a buffer and a second switching device. The second switching device is operable to bypass the buffer. A switching circuit controls switching of the first switching devices. The switching circuit includes a Gray-code counter, a Gray-code decoder, and a make-before-break circuit that controls the timing of the switching of the wiper switches.

Digital potentiometer including output buffer

A digital potentiometer, configurable and programmable using nonvolatile memory is disclosed. A unity-gain configured, rail-to-rail operational amplifier, used as voltage follower of buffer, can be inserted, by programming, between an internal wiper terminal and an output terminal of the digital potentiometer. This way, in certain applications, it is possible to take advantage of the low output resistance given by an analog buffer. The operational amplifier can be shutdown and bypassed by a switching device to provide a circuit behavior similar to a digital potentiometer without an output buffer. Using a dual-writing circuitry, first the complemented data, then the data itself, are written in the nonvolatile memory, improving the reliability. A Gray-code counter having a single bit changed at one time and no decode glitch is present. A make-before-break circuitry gives a short overlap conduction time for any adjacent pair of switches; one being turned-off while the other is turned-on. The resistor array is of high resistivity poly-type, with increased width and number of contacts, providing additional protection in short-circuited operation when the buffer is removed. The switches connected close to resistor array terminals are designed using ESD-proof rules.

Growing community of inventors

Bucharest, Romania

Adrian Macarie Tache