Tag Archives: voltage

Protecting the USB from over voltage and overcurrent threats


An application note from Littelfuse about USB protection.

This application note addresses the various requirements for protecting the Universal Serial Bus (USB) from overcurrent and overvoltage environmental threats. The solutions presented cover both USB 1.1 and the higher speed USB 2.0 circuitry. Specific emphasis is placed on USB 2.0 with information directed at hot connection over current conditions and electrostatic discharge (ESD) induced in the USB system.

Protecting the USB from over voltage and overcurrent threats – [Link]

Analog Devices AD587KN 10V reference chip


SteelCity Electronics published an article about Analog Devices AD587KN 10V reference:

I recently got hold of an Analog Devices AD587KN high precision 10.000V reference chip.
This model of chip has an output value of 10.000V ± 5mV (that is, an output value of 9.995V to 10.005V) straight out of the factory. A voltage drift of 10ppm/°C at 25°C meaning that the output voltage will drift by 10μV for each 1°C the chip is exposed to. Additionally, the chip has a voltage trim input, so if you have access to a precision voltmeter, the chip’s output value can be adjusted even closer to 10.000V.
Alternatively, the chip’s output can be trimmed to a value of 10.24V. You may think that a value of 10.24V seems like a strangely familiar number. A value of 1024 is the decimal representation of 10bits, that is 2∧10 = 1024. Why would I want a voltage reference that outputs a value of 10.24V? Because it makes any ADC or DAC conversions much simpler.

Analog Devices AD587KN 10V reference chip  – [Link]

Lowest-drift bandgap voltage reference reaches 1.5ppm/°C, offers low dropout


by Graham Prophet @ edn-europe.com:

LT6657 is a family of ultra-stable bandgap voltage references that exhibits less than 1.5ppm/°C of temperature drift. Reinforcing this performance, the device has only 0.5ppm p-p of low frequency noise, less than 30 ppm of long term drift and 35 ppm of thermal hysteresis.

The LT6657 is fully specified for –40°C to 125°C and was designed for the most demanding high performance instrumentation, test equipment and automotive systems. The LT6657’s buffered output can source and sink up to 10 mA. The LT6657 can operate on a supply voltage from as low as 50 mV above the output, up to 40V, and with a supply current of only 1.2 mA. In shutdown mode, power consumption is reduced to 4 µA. Load regulation error is less than 6 ppm/mA and line regulation error is less than 4 ppm/V, both under worst case conditions.

Lowest-drift bandgap voltage reference reaches 1.5ppm/°C, offers low dropout – [Link]


Voltage indicator transitions between colours


by Einar Abell @ edn.com:

This Design Idea gives two versions of an indicator light that changes from green to red as a battery discharges. There are many circuits that do this sort of thing, but all the ones I have seen are too complex and costly for my taste. This DI shows a method that uses an absolute minimum of low cost parts: a dual-color LED and four other parts.

Voltage indicator transitions between colours – [Link]

USB power supply active load tester


Sasa Karanovic has designed and built a DIY USB power Supply active load tester, that is available at GitHub:

USB Power supply Active Load Tester or short PAL Tester is unit designed for testing the quality of the power supplies.
Idea was to create low-cost, precise device for simultaneous measurement of Voltage and Current drawn from the device under test.

USB power supply active load tester – [Link]

50,000V High Voltage Power Supply


by Victor8o5 @ instructables.com:

This high voltage power supply has been designed to output a fixed voltage of around 50kV, it could easily be converted to an adjustable supply by connecting a variac in case of using transformers or by adding some extra circuitry to regulate the power going in. I initially thought about a high frequency PWM to regulate the power going into the capacitors, but I abandoned the idea. I found that adjusting the frequency is enough to make the voltage vary by a significant amount, allowing some control over it, this happens because the flyback must operate at a certain frequency in order to maximize the output.

50,000V High Voltage Power Supply – [Link]

SD Card Data Recorder


by sameer:

We always try to know the physical and electrical data like temperature, pressure, current, ac voltage etc. In this project, I’m going to display these data in the real time as well as I’ill record it to a memory card(SD/microSD/MMC card). Here the project can display four different things; ac voltage, environment temperature, relative humidity and the real time in 12 hrs format.

SD Card Data Recorder – [Link]

LED DC Voltage Indicator



This design is a type of indicator that is used in voltage reading. It operates as an indicator rather than a meter that drives LED for voltage indication. Voltage thresholds are 1.5, 3, 4.5 and 6V. Above each incremental threshold an additional LED turns on.

LED DC Voltage Indicator – [Link]

0-10V Voltage Monitor


0-10V Volt monitor project has been designed around LM3914 IC, It is an easy and less expensive project which instantly visualizes voltage level. The project is based on the popular LM3194 IC from Texas instruments. Handy 0-10V DC Voltmeter can be used as a voltage tester.

The LM3914 senses the voltage level at the input pin and drives the 10 light emitting diodes based on the voltage detected on input connector. Circuit works on 12V DC. J1 Jumper is used to select the DOT mode or bar graph mode.

0-10V Voltage Monitor – [Link]

LTC2966 – 100V Micropower Dual Voltage Monitor


The LTC®2966 is a low current, high voltage dual channel voltage monitor. Internal high value resistors sense the input monitor pins providing a compact and low power solution for voltage monitoring. Each channel includes two comparator reference inputs (INH/INL) to allow configuration of a high and low threshold using an external resistive divider biased from the on-chip reference. Range selection pins are provided for each channel to set the internal resistive dividers for 5x, 10x, 20x and 40x scaling. The thresholds are scaled according to the range selection settings. Additionally, either INH or INL can be grounded to enable built-in hysteresis. Polarity selection pins allow each output to be inverted. The outputs are 100V capable and include a 500k pull-up resistor to an internal supply.

LTC2966 – 100V Micropower Dual Voltage Monitor – [Link]