Tag Archives: app notes

App note: Emitters and detectors for infrared (IR) touchscreens

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App note from OSRAM about IR LEDs and IR detectors used on touchscreen technologies. Link here (PDF)

Touchscreens as a popular user interface are more and more common. Applications span from public information systems to customer self-service terminals. Thus, as a logical step, more and more devices today feature this kind of user interface, e.g. bank automatic teller machines (ATMs), personal digital assistants (PDAs), mobile phones and PC displays. The widespread popularity is actively supported by standard computer based operating systems, such as e.g. Windows® 7.

The rapid development of CMOS imaging sensors and the development of high power infrared (IR) emitters in slim packages have led to a series of new optical touchscreen technologies. Many of them contain proprietary technology and solutions.

App note: FPGA power supply considerations

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App note from Vishay Siliconix, giving us tips on powering FPGAs. Link here (PDF)

An FPGA is a device that offers many logic elements – up to 1 million gates in a single device at this writing – as well as other functionality such as transceivers, PLLs, and MAC units for complex processing. FPGAs are becoming very powerful, and the need to power the devices effectively is a key, if often underestimated, part of the design. A straightforward power supply design process can significantly reduce the number of required design iterations for the OEM designer.

App note: Inductive switching for dual 24 and 36 V High-side switch families (XS4200 and XSD200)

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Another app note from NXP describing the behavior of the SMARTMOS Dual 24 – 36 V high-side switch devices, at switch OFF when driving inductive loads. Link here (PDF)

These intelligent high-side switches are designed to be used in 24 V systems such as trucks and busses (XS4200). They can be used in industrial (XSD200) and 12 V applications as well. The low RDS(on) channels can control incandescent lamps, LEDs, solenoids, or DC motors. Control, device configuration, and diagnostics are performed through a 16-bit SPI interface, allowing easy
integration into existing applications.

App note: Repetitive short-circuit performances of the MC12XS6 IC’s family

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App note from NXP about the short-citcuit protection strategies of their MC12XS6 centralized automotive lighting drivers family IC. Link here (PDF)

The MC12XS6 devices include up to five self-protected high-side switches, with its extended protection and diagnostics, to detect bulb outage and short-circuit fault conditions. Additionally, this device incorporates a pulse width modulation control module, to improve lamp lifetime with bulb power regulation at no less than 25 Hz, and address the dimming application (daytime running light).

App note: Orientations and Rotations

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App note from Kionix on the introduction of most common method in determining orientation and rotations in an accelerometer. Link here (PDF)

The fact that accelerometers are sensitive to the gravitational force on the device allows them to be used to determine the attitude of the sensor with respect to the reference gravitational vector. This attitude determination is very useful in leveling or gimballing gyroscopes and magnetometers for use in compass and navigation instruments; determining tilt for game controller applications; and determining tilt or rotation for screen rotation of handheld devices. The method for calculating orientation or rotation depends on the specific application.

App note: Paralleling eFuses

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ON Semiconductors guide to cover much higher current capacity from eFuses. Link here (PDF)

The standard 12 V, 5 V and 3.3 V electronic fuses from ON Semiconductor provide overcurrent and overvoltage protection and come in different current limit configurations. As an example, the 5 V NIS5452 eFuse has a recommended operational 5 A current limit. Sometimes the operating current for the user system might be much higher than the maximum allowed current limit provided by the eFuse.