Stmicroelectronics (shenzhen) R&d Co. Ltd.

Stmicroelectronics S.r.l.

Shenzhen Kangning Hospital (shenzhen Mental Health Institute, Shenzhen Mental Health Center)

Mei Yang

XiangSheng Li

Cristiano Meroni

Xian Feng Xiong

Kelvin Jian Wen

Guo Zhong

Xaut Zhang

YueHua Wang

Jian Wen

Hong Xia Li

Davide Luigi Brambilla

Francesco Stilgenbauer

Xianfeng Xiong

QiYu Liu

Zheng Hua Song

Shuming Tong

Xiaojian Jia

Han Rong

Huiming Liu

Tiebang Liu

In an embodiment, an amplifier circuit includes a second stage that includes a first switch circuit including first and second terminals, a plurality of resistive elements coupled between the first and second terminals of the first switch circuit, and a plurality of switches configured to control an equivalent resistance between the first and second terminals of the first switch circuit. During play mode, the second stage has a gain between the input of the second stage and the output of the second stage of a first value. During a transition from mute mode to play mode, the amplifier circuit is configured to progressively increase the gain of the second stage from a second value to the first value. During a transition from play mode to mute mode, the amplifier circuit is configured to progressively decrease the gain of the second stage from the first value to the second value.

Play mute circuit and method

The disclosure provides a non-therapeutic method for regulating DAT gene expression in a cell, which includes the step of increasing or decreasing an amount of a miR-132/212 in the cell; further provides a use of the above miRNA, an enhancer thereof or an attenuator thereof in preparing a drug for regulating uptake of dopamine by a cell; and an application of the above miRNA, the enhancer thereof or the attenuator thereof in preparing a drug for treating psychoactive substance addiction.

Use of miR-132 and miR-212 in preparation of drug for treating addiction

In an embodiment, a power switch controller for driving a back-to-back power switch includes: an amplifier having a supply terminal configured to receive a supply voltage, an output configured to be coupled to a gate terminal of the back-to-back power switch, a first input configured to be coupled a source terminal of the back-to-back power switch, and a second input coupled to the output of the amplifier. The amplifier is configured to generate an output voltage at the output of the amplifier, the output voltage being an offset voltage higher than a voltage at the first input of the amplifier.

Back-to-back power switch controller

A circuit can be used in a speaker system. The circuit includes an amplifier with an output configured to be coupled to a speaker. An offset comparator has an input coupled the output of the amplifier and is configured to provide an offset control signal. A digital circuit has a first input coupled to an output of the offset comparator, a second input configured to receive an amplifier control signal, a third input configured to receive a play control signal, and an output configured to provide a forced mute signal that can be used to control the amplifier.

Embedded speaker protection for automotive audio power amplifier

A digital circuit can be used in a speaker system. An intermediate node provides a speaker protection control signal. A first latch for receives an offset control signal. A first logic gate receives a play control signal, the offset control signal, and the speaker protection control signal. A second logic gate is coupled to the first latch for receiving the play control signal and the speaker protection control signal. A second latch is coupled to the first logic gate for providing a forced mute signal. A third latch is coupled to the second logic gate and to the intermediate node.

A power amplifier includes a clamping circuit configured to provide a clamped voltage from a power supply; an amplifier pair having first inputs coupled to the clamping circuit, second inputs and an output for providing an amplified signal; and a biasing circuit coupled between the clamping circuit and the second inputs. The biasing circuit is configured to adjust input bias voltages of the amplifier pair such that the output of the amplifier pair varies proportionally to a change of the power supply.

Power amplifier

A method of operating a speaker system including a speaker coupled to an amplifier, and a dedicated digital speaker protection circuit includes turning on the amplifier in a mute mode, after a first delay period, issuing a play command to the amplifier to place the amplifier in a play mode, but without an input signal during a second delay period, and performing a speaker offset detection during the second delay period, wherein, if there is an offset, then the amplifier is forced back into the mute mode, and if there is no offset, then the amplifier is allowed to continue to operate in the play mode. The method also includes issuing a speaker protection control signal or command if an offset is detected.

A clamping circuit for a class AB amplifier includes a reference voltage circuit, four NPN Darlington transistors having inputs coupled to the reference voltage circuit, and outputs for providing four clamped voltages and a split NPN Darlington transistor having an input coupled to the reference voltage circuit, and four separate outputs for providing four AC ground voltages.

Input clamping structure for sound quality improvement in car-radio class-AB power amplifier design

A clamping circuit for a class AB amplifier includes a reference voltage circuit, four NPN Darlington transistors having inputs coupled to the reference voltage circuit, and outputs for providing four clamped voltages, and a split NPN Darlington transistor having an input coupled to the reference voltage circuit, and four separate outputs for providing four AC ground voltages.

A power transistor for use in an audio application is laid out to minimize hot spots. Hot spots are created by non-uniform power dissipation or overly concentrated current densities. The source and drain pads are disposed relative to each other to facilitate uniform power dissipation. Interleaving metal fingers and upper metal layers are connected directly to lower metal layers in the absence of vias to improve current density distribution. This layout improves some fail detection tests by 17%.

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Shenzhen, China

Mei Yang