This application note (PDF!) from TI details the design of Single Phase PLL:
Grid connected applications require an accurate estimate of the grid angle to feed power synchronously tothe grid. This is achieved using a software phase locked loop (PLL). This application report discusses different challenges in the design of software phase locked loops and presents a methodology to design phase locked loops using C2000 controllers for single phase grid connection applications.
TI application note (PDF!) on high voltage adjustable power supplies:
An improved approach is shown in Figure 2. Here an LM329B 6.9V zener reference has been stacked in series
with the LM317’s internal reference. This both improves temperature stability, since the LM329B has a guaranteed TC of ±20 ppm/˚C, and improves regulation, because more loop gain is available from the LM317.
These techniques can be extended for higher output voltages and/or currents by either using better high voltage transistors or cascoding or paralleling (with appropriate emitter ballasting resistors) several transistors. The output short circuit current, determined by R3, must be within Q2’s safe area of operation so that secondary breakdown cannot occur.
An app note (PDF!) from Texas Instruments on importance of latency in factory automation:
Latency is a critical parameter in Ethernet networks developed for Factory Automation applications. Latency is not a defined value for Ethernet as specified by the IEEE 802.3 standard. Nor is Ethernet inherently synchronous or repeatable. This disconnect between the inherent characteristics of Ethernet and the needs of Factory Automation applications must be bridged though careful architecture of Ethernet Physical Layer devices like the DP83867.
The latency through the Ethernet Physical Layer is a key limiting factor of control cycle time in these applications. The capability of the DP83867 to operate with less than 400ns latency in 1000Base-T operation can improve the cycle time. This low level of latency is also comparable to levels seen in 100Base-TX operation, thereby simplifying the process of upgrading a 100Base-TX network to 1000BaseT and increasing the network bandwidth.
This application note (PDF!) from TI provides on-card regulation for logic circuits:
Because of the relatively high current requirements of digital systems, there are a number of problems associated with using one centrally-located regulator. Heavy power busses must be used to distribute the regulated voltage. With low voltages and currents of many amperes, voltage drops in connectors and conductors can cause an appreciable percentage change in the voltage delivered to the load. This is aggravated further with TTL logic, as it draws transient currents many times the steady-state current when it switches.
These problems have created a considerable interest in on-card regulation, that is, to provide local regulation for the subsystems of the computer. Rough preregulation can be used, and the power distributed without excessive concern for line drops
The local regulators then smooth out the voltage variations due to line drops and absorb transients.
An app note from TI, 1-μA capacitive grip detection based on MSP430 Microcontrollers (PDF!)
This application report discusseshow to design a simple and ultra low-power grip detector Booster Pack for the MSP430 LaunchPad. The PINOSC feature in every msp430G2xx2 and msp430G2xx3 device makes it possible to eliminate all the external components when implementing a capacitive touch design. All the components used in the grip detector, such as capacitive sensors, LEDs are all integrated in a BoosterPack, which is completely compatible with the MSP430 LaunchPad interface. And this grip detector canalso communicate with the TouchPro graphical user interface (GUI) to make the test and debug process much faster and easier. Measurement results show that the average current consumed by this grip detector working in idle mode is nearly 1μA, which proves that the MSP430 value line series of devices have excellent low-power characteristics and are suitable for battery powered applications.