Dialog Semiconductor (UK) Limited

Renesas Electronics America Inc.

Fulvio Schiappelli

Alessandro Angeli

Andrea Acquas

Jiri Ledr

Giuseppe Tavano

Shyam Narayanan

An object of the disclosure is to provide a slope enhancement circuit, comprising an amplifier and a specific arrangement of capacitors and switches, further comprising a current digital to analog converter (IDAC), in a switched regulated current mirror. A method of sample and hold exploits the transient dynamics of the switched current mirror, to enhance the output current slope during PWM operation. A further object of the disclosure is to provide a low power, high speed switching type of regulated current mirror architecture. Still further, another object of the disclosure is to provide quick response to a sudden demand in current with a high degree of accuracy. Still further, another object of the disclosure is to provide a significant savings in circuit area.

Slope enhancement circuit for switched regulated current mirrors

A system for trimming a load current provided to a load terminal has a reference current circuit branch and a load current circuit branch. The reference current circuit branch has a current source, a first variable resistance element and a first decoupling resistance element connected between the current source and the first variable resistance element. The load current circuit branch has the load terminal, a second variable resistance element configured to attain a resistance value depending on a resistance value attained by the first variable resistance element, and a second decoupling resistance element connected between the load terminal and the second variable resistance element. In addition, the trimming system has voltage and current regulators. The current regulator regulates the load current based on a voltage difference between a first output terminal of the first decoupling resistance element and a second output terminal of the second decoupling resistance element.

Trimming system and method for regulated current mirrors

This application relates to a lighting system comprising a plurality of light emitting diode, LED, circuits, and a power source for providing a drive voltage to the plurality of LED circuits. For each LED circuit, the lighting system comprises a first variable resistance element connected between the respective LED circuit and ground, and a first feedback circuit configured to control a voltage at a first node between the respective LED circuit and the respective first variable resistance element to a first voltage. The lighting system further comprises a current source and a second variable resistance element connected between the current source and ground, wherein each first variable resistance element is configured to attain a resistance value depending on a resistance value attained by the second variable resistance element.

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Pullach im Isartal, Germany

Fulvio Schiappelli