App note from ROHM on known dropout voltage values for you to consider in designing with their linear regulator. Link here (PDF) The dropout voltage is the difference between the input and output voltages that is necessary for the stabilizing operation of a linear regulator. When the input voltage approaches the output voltage, stabilizing operation […]
Tag Archives: ROHM
App note: Method of suppressing increase in surface temperature of shunt resistors
App note from ROHM Semiconductor about their shunt resistor mounting designs to keep heat away. Link here (PDF) Shunt resistors are widely used for current sensing in automotive and industrial applications. In the automotive sector, as vehicles become more complex and the number of motors and ECUs grows, applications need to be configured in a […]
App note: Effect of PCB design on temperature coefficient of resistance
App note from ROHM Semiconductor on the importance of sense trace/line arrangement on PCB designs. Link here (PDF) While resistance, power rating and size are important considerations when using shunt resistors, tolerances that affect the accuracy of the detected voltage must also be considered. These tolerances include the temperature coefficient of resistance and the tolerance […]
App note: Types of capacitors used for output smoothing of switching regulators and their precautions
Another app note from ROHM Semiconductor on various capacitors used for output smoothing. Link here (PDF) In recent years, it has become a common practice to recommend multilayer ceramic capacitors for the output smoothing of switching regulators due to the stability of their temperature characteristics and the reduction on the mounting area. On the other […]
App note: 5kW High-Efficiency Fan-less inverter
A novel inverter design by ROHM and Power assist technology. Link here (PDF) We employ trans-linked interleaved circuits as inverter circuits that utilize the high frequency switching performance of silicon carbide (SiC) MOSFET, achieving a power conversion efficiency of 99% or more at 5 kW. Since this circuit topology allows a reduction in the inductance […]
App note: Voltage detector circuit collection
App note from ROHM Semiconductor on their voltage detectors IC primarily used in microntroller reset circuitry. Link here (PDF)
App note: Precautions when measuring the rear of the package with a thermocouple on power devices
App note from ROHM Semiconductors when measuring thermals along exposed pads on power devices. Link here (PDF) When measuring the rear of the package with a thermocouple, to measure accurately, the thermocouple must be in close contact with the package. A thermal pad for heat dissipation is exposed on the rear side and this thermal […]
App note: LED electrostatic breakdown
Very brief reminder from ROHM semiconductors about LED electrostatic destruction. Link here (PDF) LED products are classified as having a lower electrostatic breakage resistance than other semiconductor products. InGaN devices used in blue and white LEDs are more vulnerable to static electricity than other InGaAlP and GaP (red to yellow-green) devices.
App note: Impedance characteristics of bypass capacitor
App note from ROHM Semiconductors about different type of bypass capacitors impedance and some tip when replacing them. Link here (PDF) There are various types of capacitors. If you select parts only based on their capacitance values, the requirements for bypass capacitors may not be satisfied, leading to malfunction of devices or nonconformity to standards. […]
App note: BA1117 dropout voltage
App note from ROHM Semiconductors about linear regulator dropout voltage. Link here (PDF) The dropout voltage is the difference between the input and output voltages that is necessary for the stabilizing operation of a linear regulator. When the input voltage approaches the output voltage, stabilizing operation cannot be maintained and the output starts dropping in […]
App note: Notes for temperature measurement using forward voltage of PN junction
App note from ROHM Semiconductors about the cautions when measuring temperature from PN Junctions. Link here (PDF) The forward voltage of a pn junction can be measured to estimate the junction temperature of a semiconductor device. However, correct results may not be obtained if the measurement is performed incorrectly.
App note: What is a digital transistor?
See the simple composition of a digital transistor, app note from ROHM Semiconductors. Link here A digital transistor is a bipolar transistor that integrates resistors. Bipolar operation tends to become unstable if the input (Base) is connected directly to the output terminal of an IC for voltage control. Inserting a resistor at the Base stabilizes […]
App note: Gate-source voltage behaviour in a bridge configuration
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 […]
App note: Simple test method for estimating the stability of linear regulators
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 […]
App note: Bootstrap circuit in the buck converter
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: Linear regulator problem situations – Power supply does not start
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 […]
App note: Linear regulator specifications
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 […]
App note: Connecting LDOs in parallel
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 […]
App note: Linear regulators reverse voltage protection
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 […]
App note: Power source ON/OFF characteristics for linear regulator
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 […]