App note from Richtek on comparison of different connection of Common-N DCR current sensing and its effect on PCB resistance mismatch. Link here (PDF) It has been many years since GPU power solutions (OVR3i+ / OVR4i+) adopt common-N structure for DCR current sensing in multi-phase applications. There are two common-N type multi-phase controllers for graphic […]
Tag Archives: Richtek
App note: Comparison of DCR current sense topologies
App note from Richtek on the comparison of current sensing methods using inductor’s DCR. Link here (PDF) Current sensing plays an important role in DC/DC regulator systems, especially in multi-phase buck converters for CPU VCORE applications. In VCORE applications, the current signals are used to decide the load-line droop, per-phase current balance, current reporting, and […]
App note: Application and definition of thermal resistances on datasheet
App note from Richtek about thermal resistance calculation using component thermal parameters found on datasheets. Link here (PDF) Thermal issue has been a crucial topic for a long time since high power density and low cost requirements became popular. As a power engineer, the assessment of maximum allowable power dissipation of every component in the […]
App note: Multi-source power management design
Design tips from Richtek when sourcing/selecting parts for power supply. Link here The COVID pandemic has made it clear that the semiconductor supply chain is very sensitive to sudden changes in supply and demand, resulting in worldwide shortage of semiconductors in all fields, from consumer to automotive applications. Many company production lines had to reduce […]
App note: Low cost 8W off-line LED driver using RT8487
App note from Richtek on their RT8487 compact buck-boost LED driver. Link here RT8487 is a boundary mode constant current controller with internal high side driver, which can be used in buck and buck-boost configuration, to provide a constant output current to the (LED) load. It contains special circuitry for achieving high power factor and […]
App note: Cable compensation of a primary-side-regulation power supply
Another tech note from Richtek on power supply regulation with cable compensation. Link here Cable compensation has been used to compensate the voltage drop due to cable impedance for providing a regulated charging voltage in battery charger applications. This application note uses a novel cable compensation method, which called cable minus compensation, as an example […]
App note: Analysis of buck converter efficiency
Tech note from Richtek on buck converter profiling. Link here The synchronous buck circuit is wildly used to provide non-isolated power for low voltage and high current supply to system chip. To realize the power loss of synchronous buck converter and to improve efficiency is important for power designer. The application note introduces the analysis […]
App note: Understanding the characteristics of Li-ion batteries and Richtek power management solutions
App note from Richtek on how to work with Li-ion batteries properly. Link here Lithium-ion/polymer rechargeable batteries, which have been widely used today, have distinguished properties, but are very delicate and have to be used with extreme care. Improper use of Li-ion batteries will bring about catastrophic consequences. The incidences of burning and explosions of […]
App note: Power IC solutions for IoT / Portable / Wearable / Battery-Powered applications
A tidy and organized power solution list from Richtek. Link here (PDF)
App note: How to eliminate over stress of MOSFET during start-up of flyback converter
App note from Richtek about their embedded soft-start function to eliminate MOSFET stress. Link here Switching Power Supply, compared to Linear Power Supply, is widely used due to its advantages, such as small size, light weight, high efficiency, etc. Flyback Converter, one of the switching power supply topologies, is most suitable for power supply systems […]
App note: Minimizing light flicker in LED lighting applications
Another application notes from Richtek this time on LED lamps flickering. Link here Applying LEDs in offline retrofit lamps seems straightforward, but should be done with care to achieve similar light quality as the conventional lamp that the user is trying to replace. Light flicker is one of the aspects that need to be considered […]
App note: Li-ion battery and gauge introduction
Richtek app note for Li-ion battery definitions and gauge introduction. Link here SOC is defined as the status of available energy in the battery and usually expressed as percentages. Because the available energy change depends on different charging/discharging currents, temperatures and aging effects, the SOC could be defined more clearly as ASOC (Absolute State-Of-Charge) and […]
App note: The reduction of input voltage spike on power switches
Another app note from Richtek introducing solutions for reducing the input voltage spike on power switches. Link here The power switch is a low voltage, single N-Channel MOSFET high-side power switch, optimized for self-powered and bus- powered Universal Serial Bus (USB) applications. In worse operating condition, an input voltage spike may over the chip’s maximum […]
App note: Analyzing VIN overstress in power ICs
Investigative app note from Richtek about the component failure point caused by EOS. Link here (PDF) Failures in power ICs are often the result of Electrical Over Stress (EOS) on the IC input supply pin. This report explains the structure of power IC input ESD protection and how ESD cells can become damaged due to […]
App note: DC/DC converter testing with fast load transient
Another app note from Richtek, this time about transient load testing on power converters and how you can make a simple and low cost fast transient tool. Link here (PDF) Load transient testing is a quick way to check power converter behavior on several aspects: It will show the converter regulation speed and can highlight […]
App note: RT2875 3A automotive buck converter
An application note from Richtek on buck converter used in automotive application. Link here (PDF) Automotive environment can be quite harsh and designing electronics that need to work reliable in this environment takes special care, and often requires automotive qualified parts. When designing voltage regulators that need to step down an intermediate voltage from the […]
App note: Designing applications with Lithium-Ion batteries
More Li-ion battery applications from Richtek. Link here (PDF) Lithium-Ion batteries have several advantages when compared with other battery types: They are light weight, and energy density of lithium-ion is typically twice that of the standard nickel-cadmium. Li-Ion batteries have no memory effect, and the self-discharge is 6 ~ 8 times less compared to nickel-cadmium. […]
App note: Switching battery chargers
App note from Richtek about several aspects of switching chargers for single cell Li-Ion batteries. Link here (PDF) Longer battery life and shorter charging times are some of the challenges in battery management in modern hand-held applications like Smart-Phones, Tablet PCs, POS and other portable equipment. Devices with powerful processors are more power hungry and […]