Tag Archives: app notes

App note: Monitoring additional supplies with the ADM1062–ADM1069 super sequencers

via Dangerous Prototypes

App note from Analog Devices about ways to extend capabilities of their ADM106x supply supervisor and sequencer chip. Link here (PDF)

The ADM1062–ADM1069 Super Sequencers accurately monitor a number of input rails. The ADM1062–ADM1067 have 10 input pins dedicated to monitoring (VH, VP1 to VP4, VX1 to VX5) and the ADM1068 and ADM1069 have eight (VH, VP1 to VP3, VX1 to VX4). Each of these pins has two internal programmable comparator circuits. By programming these circuits undervoltage only, overvoltage only or undervoltage and overvoltage trip points can be set up around each monitored supply. These trip points are 1% accurate at all allowable voltages and across the entire operational temperature range of the devices.

App note: Failure signature of electrical overstress on power MOSFETs

via Dangerous Prototypes

Nexperia app note about MOSFET’s destruction investigative hints that can be used for design improvements. Link here (PDF)

When Power MOSFETs fail, there is often extensive damage. Examination of the size and location of the burn mark, the failure signature, provides information about the type of fault condition which caused the failure. This document provides a catalogue of failure signatures from common electrical overstress failure modes. The catalogue can be used in forensic investigation of the underlying root cause of failure to improve module design and reliability.

App note: Designing in MOSFETs for safe and reliable gate-drive operation

via Dangerous Prototypes

This app note from Nexperia discuss’ gate drive designs for safe operation of MOSFET. link here (PDF)

The MOSFET gate-source threshold voltage (VGS-th) and maximum gate-source voltage (VGS-max) are key parameters that are critical to the reliable operation of MOSFETs. The threshold voltage represents the voltage at which the MOSFET starts to turn on, whilst the maximum gate-source voltage is the maximum gate-source voltage that the MOSFET can withstand safely. VGS-max ratings vary between suppliers and between MOSFETs, which can make it difficult to choose appropriate MOSFETs for the application.

App note: How to protect mobile devices from ‘USB Kill’ threats

via Dangerous Prototypes

Great read from Bourns about USB killer devices and port protection solutions. Link here (PDF)

Researchers have long warned about the security risks of inserting other users’ USB drives into your PC, even those from whom you trust. If the threat of malware infections isn’t cause enough for concern, there have been stories of malicious USB thumb drives that have “fried” laptops. Does this seem like a far-fetched occurrence? Hearing of the threats, PC World documented the work of an electronics engineer who set out to create a prototype that could actually kill a mobile device’s USB port.

App note: Protecting USB Type-C Cable connectors featuring higher power & tighter pin spacing

via Dangerous Prototypes

Bourns’ built-in thermal cut-off devices adds extra protection from faults directly on USB Type-C cables. Link here (PDF)

The now ubiquitous Universal Serial Bus (USB) standard was initially developed in 1994 with the intent of providing a communication standard to improve and simplify communication between the PC and peripheral devices. An updated version of the USB interface standard is the USB 3.1 Superspeed+, which doubles the data rate to 10 Gbps – a 2x improvement of the previous generation USB 3.0 Superspeed. USB 3.1 Superspeed+ is backwards compatible with USB 1.1, 2.0 and 3.0 with a power delivery projected at 100 W. This gives users enhanced data encoding for more efficient data transfer offering higher throughput and improved I/O power efficiency.

In addition to the increased power capability and bandwidth achieved in this updated USB standard, the connector has been changed. The original simple 4 pin D+/ D- Power and GND format has been upgraded and now combines multiple connector functions into one. The new USB Type-C connector features 24 pins in a smaller form factor.

A downside to this combination of increased power and the extremely tight pin spacing is heightened concern about potential safety and fire hazards due to the possibility of thermal runaway at the connector. To deal with these potential threats, it is recommended that electronic equipment manufacturers and connector and cable manufacturers integrate overcurrent and overtemperature protection into the Type-C connector.