Driving electronics for OLED lighting

This paper proposes the concept of integrating an OLED (foil) and its driving electronics into one module. A complete light system consisting of these modules is the ultimate goal of this work. The main focus in this article is on the design of the driver chip and the circuit implementation. The measurement results confirm that it is possible to control the light output of the different modules

A modular and interactive OLED-based lighting system

The concept of a flexible, large-area, organic light emitting diode (OLED)-based lighting system with a modular structure and built-in intelligent light management is introduced. Such a flexible, thin, portable lighting system with discreetly integrated electronics is important in order to allow the implementation of the lighting system into a variety of places, such as cars and temporary expedition areas. A modular construction of an OLED lighting panel makes it possible to control each OLED cell individually. This not only enables us to counteract aging or degradation effects in the OLED cells but it also allows individual OLED module brightness control to support human or ambient interaction based on integrated or centralized sensors. Moreover, integrating the driving electronics in the backplane of an OLED module improves the energy efficiency of operating large OLED panels. The thin, modular construction and individual, dynamic control are successfully demonstrated

Fabrication of a shear stress sensor matrix using standard printed circuit board and overmolding technologies

In contrast to pressure distributions that can nowadays easily be measured using commercial sensor sheets, this is not yet the case for frictional or shear stresses. Those stresses act parallel to a surface which makes it more challenging to develop suitable sensors. A number of shear sensor prototypes have been reported until now, but realizing a matrix of shear sensors remains a big challenge because of cost and complexity issues. Therefore, this paper presents a fabrication approach for realizing a matrix of shear sensors using standard PCB and moulding technologies. The presented sensor is based on changing the coupling of optical power between a Light Emitting Diode and a set of photodiodes in combination with an overmoulding step, as such realizing a mechanical transducer. To demonstrate the fabrication flow, a first demonstrator incorporating a 5-taxel sensor matrix has been realized, able to record the in-plane shear stress magnitude and direction

An intelligent driving scheme for high-voltage display drivers

An algorithm to reduce the power consumption in bistable display drivers is presented. This algorithm can also be used in other flat panel displays like OLEDs, standard (S)TN LCDs,... and is very important for battery-powered applications. The complete block diagram of the low-power high-voltage display driver and a comparison of the normalized frame energy for different driving schemes and different patterns are presented

Design and characterization of a secondary side smart-power integrated active asynchronous voltage clamp

As is well known in the design of transformer isolated converters, the transformer leakage inductance causes a large voltage overshoot on the secondary side switching nodes at every switch transition, unless measures are taken to limit the peak voltage stress. Since the peak voltage stress in smart-power integrated converters, where the power devices are integrated on the same die as the controlling logic and supporting circuits, is the major determining factor for the required silicon area for the implementation, this is a major roadblock for the affordable integration of this type of converter. Therefore, any cost-effective smart-power synchronous rectifier requires a voltage clamping circuit that minimizes the voltage stress, while still maintaining the potential advantages of smart-power converters, i.e. minimizing the number and size of the discrete components in the converter. We present an integrated asynchronous active clamping circuit, that can clamp the overshoot voltage to arbitrary voltages while optimizing the efficiency by only being active when required. Because of the asynchronous operation, the size of the required external components is minimized. Measurements on the smart-power IC implementation of the asynchronous active clamp circuit combined with a secondary side synchronous rectifier for a 1 MHz full bridge converter confirm the reduction in voltage stress and the optimization of the efficiency

A completely integrated power-efficient high-voltage driver for bistable displays

This article describes a completely integrated new driver for bistable displays. The extra logic that is added combined with special dynamically controlled High-Voltage (HV) switches that connect the rows and columns of the display to the appropriate HV sources results in a power saving of about 50% compared with traditional drivers

Design of an integrated OLED driver for a modular large-area lighting system

The concept of a flexible, large-area, OLED-based lighting system with a modular structure and built-in intelligent light management is introduced. The paper describes the design of a high-voltage integrated circuit for driving and controlling an individual OLED tile in this modular lighting system. The chip comprises a switching DC-DC buck converter for generating the OLED current and a sensitive analog feedback loop for adjusting the duty cycle of the converter’s PWM control signal. The chip was designed in the 80V 0.35µm I3T80 technology of ON Semiconductor

A power-efficient way to operate high-voltage bistable display drivers

The analog and digital part of a power-efficient high-voltage bistable display driver is presented. A new algorithm for the global reset and a summary of the most interesting power-saving principles that will be used to drive the displays, together with some theoretical results and a short description of the high-voltage switches that will be used to connect the voltages to the display, are given