Tag Archives: app notes

App note: ESD protection audio input and output lines

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Audio port protection discussed in this app note from Littlefuse. Link here (PDF)

Externally generated ESD pulses are introduced through the Audio jacks (headphone, microphone, RCA-type plugs, etc.) and travel through the connector onto the system board. Once on the board, they will propagate down the signal lines toward the integrated circuits(IC). Most ICs are designed with 2,000V of internal ESD protection. It is not uncommon to measure ESD transients in consumer environments over 8,000V.Without sufficient protection, the Audio system can experience visual distortion or corrupted data. In addition, the IC could be permanently damaged rendering the whole system inoperable.

App note: Coordinated circuit protection options for LED lighting

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App note from Littelfuse on protecting LED lights from overloaded circuits, overvoltage and electrical shorts assuring safety on customers from these hazards. Link here (PDF)

LED technology has advanced rapidly, with improved chip designs and materials facilitating development of brighter and longer-lasting light sources that can be used in a wide spectrum of applications. A growing awareness of the need to reduce energy costs has also made LED lighting increasingly popular.
In spite of the growing popularity of the technology, LED light manufacturers continue to wrestle with the fact that LED luminaires are very heat sensitive. Excessive heat or inappropriate applications can dramatically affect performance.

App note: Single channel smart load switch use and selection

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App note from Diodes Incorporated present you their solution to put a safeguard on your load from transients spikes and shorts, these load switch also do have monitoring pins in order to show the condition of the supply line. Link here (PDF)

Single Channel Smart load switch provides a component and area-reducing solution for efficient power domain switching. In addition to integrated control functionality with ultra-low on resistance (<15 mΩ), this device offers system safeguards and monitoring via the fault protection (Short circuit protection, SCP) and power good signal. This cost effective solution is ideal for power management and hot-swap applications requiring low power consumption in a small footprint.

App note: Suppression of transients in an automotive environment

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App note from Littelfuse about automotive electrical noises and where they came from and what to do with them in order to prevent it from going to your circuit. Link here (PDF)

As the control circuitry in the automobile continues to develop, there is a greater need to consider the capability of new technology in terms of survivability to the commonly encountered transients in the automotive environment. The circuit designer must ensure reliable circuit operation in this severe transient environment. The transients on the automobile power supply range form the severe, high energy, transients generated by the alternator/regulator system to the low-level “noise” generated by the ignition system and various accessories.

App note: An introduction to transient voltage suppression devices

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App note from Littelfuse introduces you to their TVS options specifically fit to your circuit protection needs. Link here (PDF)

Transient Voltage Suppression (TVS) protection devices such as shielded cables, crowbars, filters and clamping devices have been widely used for a number of years to solve EMI problems. These TVS devices can be used to achieve higher EMI higher immunity levels without significantly adding to the cost and complexity of the circuit. The attributes of traditional TVS devices will be compared to the features of a relatively new option, the avalanche diode TVS EMI filter. Recent advancements in IC manufacturing technology provide the TVS diode with several technical and cost advantages compared to traditional EMI devices.

App note: Buck-Boost charger MOSFETs

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Selecting the desired MOSFET fit for Buck-Boost for higher efficiency in power supply and battery charging section discussed in this app note from Alpha & Omega Semiconductors. Link here (PDF)

The wide adoption of USB Type-C PD makes the notebook PC charger move to four MOSFET buck-boost charger topology to allow for wide range input voltage (5-20V). After a suitable controller is selected, the specified Power MOSFETs in buck-boost charger are essential for achieving higher efficiency and high-power density design.
In this application note, we will only discuss the USB power delivery specification for an adapter supplying 5A/100W and expect the reader to understand the basic operation of buck-boost topology. It is critical to select suitable MOSFETs regarding efficiency, thermal, and space limitation, to meet the system-level requirements. 30V MOSFETs can be used for input voltage below 20V.
Based on given wide input voltages, output voltages, and current, the designer must understand the tradeoff among the different loss mechanisms in the MOSFET. These MOSFET losses include: switching loss, conduction loss, and reverse recovery loss. Losses are minimized by selecting the best MOSFETs from its electrical characteristics.