Dialog Semiconductor Gmbh

David Clewett

Julian Tyrrell

Stuart Levine

Toshiki Kitaguchi

Anna Hedley

Circuits and methods to achieve a switch interface circuit for a single pole, single throw (SPST) momentary push-button switch consuming a few tens of nanoamps whilst the push-button switch is closed, having low impedance input path when the switch is open in order to eliminate RFI interference have been achieved. The two states of the push-button switch, open and closed, maintain a low impedance path to one of the power supplies. The supply current is zero when the switch is open and is minimized whilst the switch is closed. The asynchronous edge triggered detection of the switch event allows an extended switch open to closed transition operation.

Ultra-low current push-button switch interface circuit

Circuits and methods to operate an arrangement of one or more charge pumps with two or more power supplies where each supply is able to vary over a range of voltages, and where any one supply can be of a higher or lower voltage than any of the others have been achieved. In a preferred embodiment the output of the arrangement of charge pumps is used to drive an electronic display. The strongest power supply available is selected and the arrangement of one or more charge pumps is reconfigured according to the value of the actual strongest supply voltage. In case of a change of a source of supply voltage the operation of the charge pumps during the short time required for reconfiguration. While the charge pump is running it can be suspended, reconfigured and released or restarted in the case of a change of supply source, or simply reconfigured on-the-fly without suspending in the case of a selected supply voltage change.

Autonomous control of multiple supply voltage generators for display drivers

A system, a circuit and a method are given, to realize a display control and driver interface with graphic display memory, whereby the use of dynamic RAM rather than static RAM for this graphic display memory is new. This has the advantage, that for a given size of display memory (number of bits) the DRAM silicon area is significantly less than that of the SRAM. Said system and circuit are designed in order to be implemented with a very economic number of components, capable to be realized with modern monolithic integrated circuit technologies and implementing the given method. This display controller and driver chip can then be used for all LCD display devices including STN (Super Twisted Nematic), CSTN (Colour STN), TFT (Thin Film Transistor) LCD's and for OLED (Organic Light Emitting Diode) displays.

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Swindon, United Kingdom

David Clewett