App note from ROHM semiconductor on MOSFETS and IGBTs. Link here (PDF)
Power switching devices such as MOSFETs and IGBTs are used for various kinds of power supply applications, power supply line switching components, and other power applications. In addition, the circuit topologies used are diverse, parallel and series connections are widely used, not to mention single device use. Especially in bridge circuit configuration, in which the devices are connected in series, it is common to turn on and turn off each device alternately. Due to the current flowing and the voltage change in each device, the devices greatly affect one another. In this application note, we focus on Gate-Source voltage in MOSFET bridge configuration based on one of the simplest power circuits, a synchronous rectification boost converter to understand the switching operation in detail.
Tips from ROHM Semiconductor to estimate the stability of linear regulator using simple step response method. Link here (PDF)
Low drop-out (LDO) regulators developed back in the age when large-capacitance multi-layer ceramic capacitors (hereinafter, MLCCs) were uncommon cause a phase delay, leading to oscillation when connected to a low-ESR capacitor like an MLCC. Often, MLCCs are used to save board space and prolong the lives of electronic components. A resistor placed in series in the circuit increases apparent ESR and establishes a phase lead that enable the use of an MLCC as an output capacitor. Phase margin measurement is practical on an LDO having variable output voltage, since its feedback loop is outwardly exposed. However, on a fixed output voltage LDO, the phase margin cannot be measured because of its closed loop circuit.
App note from ROHM Semiconductor about bootstrap capacitor used in switching regulator chip. Link here (PDF)
This application note explains the step-up circuit using a bootstrap capacitor. In buck converters, this circuit is used when the highside switch is the N-ch MOSFET.
App note from ROHM Semiconductor about various start up problem on 3 pins linear regulator. Link here (PDF)
Although linear regulators can be used to easily configure power supplies, the linear regulators may cause startup problems depending on the type of loads. This application note introduces cases where the power supplies do not start correctly in the linear regulators.
Thorough items on a linear regulator datasheet provides valuable details about its proper usage discussed in this App note from ROHM semiconductor. Link here (PDF)
A linear regulator data sheet includes a specifications table that lists output voltage values and precision. Besides, very important information such as maximum ratings, operating conditions and characteristic graphs are described in the table.
App note from ROHM semiconductor on combining LDOs for higher load capacity. Link here (PDF)
When you want to increase the output current capacity of an LDO, or when the power dissipation of a single LDO is insufficient, you might think of connecting LDOs in parallel if you need to disperse the dissipation using two LDOs. This application note provides some hints on how to connect LDOs in parallel.
Various input and output reverse voltage protection method for linear regulators discussed in this app note from ROHM. Link here (PDF)
A linear regulator integrated circuit (IC) is a DC-to-DC buck converter system that reduces a DC supply from higher voltage level to a lower voltage level, thus it requires that the input voltage is always higher than the regulated voltage. Output voltage, however, may become higher than the input voltage under specific situations or circuit configurations, and that reverse voltage and current may cause damage to the IC. A reverse polarity connection or certain inductor components can also cause a polarity reversal between the input and output terminals. This application note provides instructions on reversed voltage polarity protection for ICs.
A good read app note from ROHM on linear regulator On and Off characteristic. Link here (PDF)
When a linear regulator IC is turned ON, the electric charge is stored in the output capacitor and the output voltage increases up to the specified value. At this time, an inrush current flows from the input to output of the IC. The output voltage drops when the input power source is disconnected. This application note explains the series of operations when the power source is turned ON/OFF.