App note: Infrared remote control implementation with MSP430FR4xx


Infrared remote control implementation with MSP430FR4xx application note from TI:

This application report provides an insight into several of the most frequently used infrared protocols and especially their flexible implementation using the TI MSP430FR4xx series of low-power microcontrollers.
The MSP430FR4xx microcontrollers are primarily targeted at remote control application that are equipped with infrared modulation function and an LCD display. The infrared modulation combinatory logic works with rich peripheral resources (for example, timers, RTC, WDT, and SPI) to generate infrared waveforms for transmitting infrared signals with minimal software overhead and intelligent power consumption.

App note: TPS25810 Charging Port Over USB Type-C™


Allow more current from USB Type-C port, an application note from Texas Instruments utilizing TPS25810 and TPS2544 USB port manager. Link here (PDF)

The TPS25810 is a USB Type-C downstream facing port (DFP) controller that monitors the USB TypeC™ configuration channel (CC) lines to determine when a USB device is attached. When the upstream facing port (UFP) device Type C-to-B dongle is plugged in, the port supports connection of Type-B receptacle devices such as a mouse, smartphones, keyboards, external hard drives, and so forth. As these devices monitor the USB 2 data line (D+/D–), the TPS2544 USB charging port controller can be added to provide the electrical signatures on D+/D– to support BC1.2 and non-BC1.2 compliant charging schemes. This application note presents the design solution which offers fast charging of popular mobile phones, tablets, and media devices over the USB Type-C port.

App note: bq77905 20S cell stacking configuration


Application note from Texas Instruments on their bq77905 ultralow power stackable battery protector. Link here (PDF)

The bq77905 is a 3-5S Low Power Protector with easy stacking capabilities for higher than 5S cell battery packs. This document provides an example for setting up a stacking configuration with the bq77905 and exhibits detailed analysis of the stacking functionality.

App note: Sensorless speed stabilizer for a DC motor


Precision Microdrives’ sensorless speed sense by exploiting speed dependent back EMF voltage. Link here

Motor speed is a parameter of a DC motor that is often measured and controlled, usually through additional sensors and with closed loop feedback. This method of speed control requires some form of speed sensor, normally mounted on the motor shaft. Some of our DC motors and gearmotors have rear shafts for just this purpose

Hall sensors and opto sensors are commonly used with digital controllers, whilst analogue circuits often use tacho-generators. With PWM control it is possible to achieve good accuracy, flexibility, and reduce power losses. However this comes at the cost of an additional component and potentially a mechanical design modification if you’re planning to use it in an existing product.

For brushed DC motors it’s possible to measure and control speed without any sensors on the motor, exploiting a basic characteristic – speed dependant back EMF voltage.

App note: Lifetime of DC vibration motors (MTTF & FIT)


DC vibration motors failure analysis by Precision Microdrives. Link here

Reliability is an important consideration for engineers and product designers. It is also very context specific. For example consider a car, which is made from lots of individual components. If the radio antenna should fail, the car still operates. However this is not the case if the engine stops working. Some features are more important than others, especially with safety systems such as the car’s brakes.

In relation to vibration motors and their typical applications we can consider them as individual components or entire systems. Haptic feedback on a user interface is comprised of the input system (such as a touchscreen), the microcontroller, the motor drive circuit, and the vibration motor. If any one of these should fail, then the vibration feature will no longer work.

As with any component, our vibration motors will eventually stop working. The key therefore is accurately estimating when, and determining if it is an acceptable period of time. To do this, we can use one of a number of different methods for calculating the probability of a component’s life expectancy.

App note: Advantages of eFuses versus PTC resettable fuses


The advantage of eFuses an application note from ON Semiconductors. Link here (PDF)

Overcurrent protection is a basic necessity for electrical devices. While many people are familiar with fuses and household circuit breakers, few are intimately familiar with the kinds of overcurrent protection devices that are found in electronics.

Though not a comprehensive list, there are basically three types of overcurrent protection devices in electronics. In order of increasing sophistication they are:
• One−shot fuses
• Positive temperature coefficient (PTC) resettable fuses
• Electronic fuses (eFuses)

In many cases, a PTC may provide adequate protection. Its response should be fast enough to prevent burn damage to wiring. In addition, its ability to maintain voltage levels in response to a fault can be enhanced by choosing a higher current supply, or perhaps even adding decoupling capacitance on the power supply (input) side.
However, in other cases an eFuse is not only a better choice but its superior performance and features are required to satisfy application requirements. The use of an eFuse may also save cost and board space if additional circuitry, needed to prevent inrush currents or to provide overvoltage protection, can be eliminated by using an eFuse.

App note: LDC0851 quick-start guide


Texas Instrument’s differential inductive switch LDC0851 application guide. Link here (PDF)

Texas Instruments introduced the LDC1000 in 2012, the industry’s first inductance to digital converter. LDC1000 revolutionized the world of proximity sensing by delivering increased reliability, high resolution, and lower total system cost.

The LDC1000 was soon followed by second generation multi-channel LDC devices like the LDC161x and LDC131x. With up to four sensing channels and 28 bits of resolution the second generation of LDC devices opened the technology up to a wider range of applications and simplified system design. However, TI firmly believed that Inductive sensing could be simplified further. The LDC0851 is a differential inductive switch with a push/pull output that does not require digital programming to enable simpler deigns and lower system cost. This Application Note is a three-step guide to becoming a LDC0851 power user.