App note: Frequency measurement guidelines for oscillators

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Application note from SiTime about frequency measurements and how some methods may not gauged accurately. Link here

Every digital electronic device requires a reference clock and oscillators are widely used to serve that purpose. Verifying frequency characteristics of high performance devices requires accurate frequency measurement. This document contains an overview of various frequency measurement methods and instruments and is intended to help the users of SiTime MEMS oscillators take accurate frequency measurements.

App note: Selecting inductors for buck converters

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An application note (PDF!) from Texas Instruments on inductor selection:

This application report provides design information to help select an off-the-shelf inductor for any continuous-mode buck converter application.
The first part shows how the designer should estimate his requirements, specifically the required inductance.
The next part takes an off-the-shelf inductor and shows how to interpret the specs provided by the vendor in greater detail. A step-by-step procedure is provided.
Finally, all the previous steps are consolidated in a single design table, which answers the question: “How will the selected inductor actually perform in a specific application?”

App note: Alkaline battery low-voltage indicator

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Battery low-voltage indicator made from two new comparators TSM9118 and TMS9119 from Silicon Labs. Link here (PDF)

In many battery-powered systems, a user would like to know when it is time to replace the batteries before they are completely discharged, causing the device being powered to fail completely. Alkaline batteries have an open cell voltage of about 1.5 V. As they are discharged, the voltage slowly drops. When the cell voltage reaches about 1.25 V, they have delivered about 90% of their stored energy.

App note: A practical look at current ratings

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An app note from Alpha & Omega Semiconductors about proper way of evaluating MOSFET’s power handling capability based on how much loss it will generate based on the application conditions. Link here (PDF)

System designers are often faced with the task of selecting the most suitable power device from a wide array of products from different manufacturers with very similar ratings. While a detailed parameter by parameter comparison is technically the most correct way of selection, it is not the most practical and designers resort to making their first cut based on 3-4 simple parameters. Among these are package, voltage and current ratings, Rdson etc. In this article we will take a close and practical look at the current rating. For purposes of illustration we will focus on Mosfets in low and medium power packages, but the considerations can be applied to other technologies as well.

App note: Precision temperature-sensing with RTD circuits

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Precision temperature-sensing with RTD circuits application note (PDF!) from Microchip

This application note focuses on circuit solutions that use platinum RTDs in their design (see Figure 1). The linearity of the RTD will be presented along with standard formulas that can be used to improve the off-theshelf linearity of the element. For additional information concerning the thermistor temperature sensor, refer to Microchip’s AN685, “Thermistors in Single Supply Temperature Sensing Circuits” [ 7]. Finally, the signalconditioning path for the RTD system will be covered with application circuits from sensor to microcontroller.

App note: Performance capability of the SO8-FL package

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MOSFET SO8-FL package app note from ON Semiconductors provide same thermal performance as metal top package with heat sink attached. Link here (PDF)

The SO8−FL package can deliver high power density and provides excellent thermal dissipation to create a high efficiency, cool design environment when properly cooled. Metal−top devices attempt to remove heat easier through direct contact to the source. This application note provides a comparison of an SO8−FL device with a metal top device of comparable die parameters, and will show that the SO8−FL and metal top devices have comparable thermal performance. Furthermore, it will be shown that while the package itself influences thermal performance, the use of a heat sink provides the largest improvement to thermal dissipation, regardless of package.

App note: PCB design guidelines that maximize the performance of TVS diodes

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Correct TVS diodes location on the PCB provides optimal protection from surge, an application note from ON Semiconductors. Link here (PDF)

Transient Voltage Suppressors (TVS) avalanche diodes and diode arrays can be used to protect sensitive electronic components from the surge pulses that arise from ESD and EMI. The small size, fast response time, low clamping voltage and low cost of TVS diodes provides for an effective solution to prevent surge problems. Avalanche TVS diodes and diode arrays are relatively simple devices to use to suppress surge voltages. Only a few PCB design rules must be followed to optimize the ESD and EMI immunity level of the protection circuits.

App note: Single-cell battery discharge characteristics using the TPS61070 boost converter

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TI’s application note (PDF!): Single-cell battery discharge characteristics using the TPS61070 boost converter

This application report presents practical single-cell battery discharge characteristics in real-world application, and primarily focuses on the varying internal impedance of a battery and how that affects the battery terminal voltage.

 

App note: Using the TPS5430 as an inverting buck-boost converter

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A Texas Instruments application note (PDF!) on using the TPS5430 as an inverting buck–boost converter:

The wide input voltage range SWIFT™ (Switcher With Integrated FET) dc/dc converters are typically used as step-down converters where the derived output is a positive voltage less than the input voltage source. In some cases, it may be required to generate a negative voltage from the input voltage source. In such instances, it is possible to configure the TPS5430/20/10 devices in an inverting buck–boost topology, where the output voltage is negative with respect to ground.