App note: On-grid solar microinverter on Freescale MC56F82xx/MC56F82xxx DSCs


Application note from Freescale Semiconductor about microinverter solution develop together with Future Electronics. Link here (PDF)

In recent years, demand for renewable energy has increased significantly. The development of devices utilizing clean energy such as solar, wind, geothermal, and fuel cells attracts more and more attention. Solar energy harvesting is developing fast and will play a more important role as a global energy source. One of the ways to capture solar energy is via photovoltaic power generation systems, which are connected to the grid through power inverters. Therefore, many companies are focusing on development of photovoltaic grid-tie inverters. Freescale offers digital signal controllers, the MC56F8xxx family, that are well suited to ongrid solar inverter designs.

App note: Implementation of a single-phase electronic watt-hour meter using the MSP430AFE2xx


Another energy meter from Texas Instruments using MSP430AFE2xx. Link here (PDF)

This application report describes the implementation of a single-phase electronic electricity meter using the Texas Instruments MSP430AFE2xx metering processors. It includes the necessary information with regard to metrology software and hardware procedures for this single chip implementation.

App note: Atmel AVR465: Single-phase power/energy meter with tamper detection


A good read from Atmel on their 8-bit microcontroller single-phase energy meter design. Link here (PDF)

This application note describes a single-phase power/energy meter with tamper logic. The design measures active power, voltage, and current in a single-phase distribution environment. It differs from ordinary single-phase meters in that it uses two current transducers to measure active power in both live and neutral wires. This enables the meter to detect, signal, and continue to measure reliably even when subject to external attempts of tampering.

App note: Capacitance change with applied DC voltage


Tantalum comparison to other types of capacitors shows stable capacitance in this app note from Vishay, Link here (PDF)

Tantalum capacitors in general – and Vishay’s 298D/TR8/TM8 MicroTan tantalum capacitors in particular – demonstrate very stable performance over the DC voltage (bias) applied in an application. At the same time, the majority of capacitors utilizing ceramic or polymer dielectrics (monolithic ceramic, disc ceramic, MLCC, polyester, film, etc.) demonstrate significant shift in both directions – sometimes 40 % to 50 % or higher

App note: Extend current transformer range


Design note from Texas Instruments on technique in resetting and negative voltage generation from current transformers. Link here (PDF)

Transformers are used extensively for current sensing because they can monitor currents with very low power loss and they have wide bandwidth for good waveform fidelity. Current transformers perform well in applications with symmetrical AC currents such as push-pull or full bridge converter topologies. In single-ended applications, especially boost converters, problems can arise because of the need to accurately reproduce high duty factor, unipolar, waveforms. Unipolar pulses may saturate the current transformer and, if this happens, overcurrent protection will be lost and, for current mode control, regulation will be lost and an over voltage condition will result.

App note: USB Type-C, CC Pin Design Considerations


Application note from ON Semiconductor on USB Type-C connector supporting non-USB standard charging protocol, Link here (PDF)

When designing hardware systems with Type−C connectors, a designer also has to consider all legacy, standard, and non-standard specifications that exist in the USB connector eco system. With the introduction of the Type−C connector and the Configuration channel (CC Pin) new challenges occur trying to ensure overall system robustness. This note addresses some of the concerns with the CC pin in a robust system environment.

App note: PCB routing methodology for SuperSpeed USB 3.1 switch family from ON Semiconductor


Routing USB 3.1 traces app note from ON Semiconductor. Link here (PDF)

The introduction of USB Type−C has provided a significant launch opportunity for USB3.1 data rates across an array of platforms from portable to desktop and beyond. This proliferation of Type−C will certainly create challenges due to the high speed nature of the interface. High Speed USB2.0 presented enough of a system design challenge for tiny mobile device OEM’s trying to pass USB eye compliance. A 10X or even 20X increase in data rates will propagate that challenge far beyond the issues that were raised with HS. PCB traces in these systems must be treated as sensitive transmission lines where low-loss impedance control is king. Every effort must be made to make these paths as ideal as possible to prevent signal loss and unwanted emissions that could infect other systems in the device.

App note: How to measure the power consumption of a peripheral


Application note from NXP Semiconductors on MCU peripheral power consumption measurement. Link here (PDF)

This Application Note outlines the steps to measure the power consumption of a peripheral and figure out some key points in the measurement. The document takes low-power timer (LPTMR) and LPUART as examples to introduce the method to measure the power consumption of peripheral. The test code is developed in IAR and FRDM-KE15Z board.

App note: TEA1938T GreenChip SMPS control IC


TEA1938T SMPS control IC application note from NXP Semiconductors. Link here (PDF)

The TEA1938T is a high-featured low-cost DCM and QR mode flyback converter controller. It provides high efficiency at all power levels and very low no-load power consumption at nominal output voltage in burst mode operation.

To minimize ripple, the burst mode uses a small hysteresis scheme. The TEA1938T is designed to support multiple-output-voltage applications like USB PD (Type C) power supplies. Typical applications include notebooks and tablet adapters, fast charging, and direct charging adapters.

App note: Using trench technology MOSFETs in hot swap applications


Safely use trench MOSFETs on hot swap application by determining its operation within its SOA in a limited time, app note from International Rectifier. Link here (PDF)

Hot Swap circuits are used to allow for “Hot Plugging” of circuit boards into back planes. The applications that require such functionality are mission critical, such as servers and communications equipment that must operate continuously. These circuit boards are usually employed in a rack mount system which consists of an array of boards that cannot be powered down. Thus hot swapping allows for a bad board in the array to be replaced without powering down the entire system.

In essence the Hot Swap circuit, which is between the board input rail and the rest of the board’s circuitry, is an inrush current limiter that allows for charging of the bulk capacitance in a controlled manner. Also faults, such as over current and overvoltage are managed by Hot Swap circuits.