App note: Novel current-sense measurement with automatic offset correction


Silicon Labs’ application note about a low power current measurement circuit using TS1001 nano power op-amp paired with low-power CY8C38 microcontroller, Link here (PDF)

Pairing a simple circuit using nanopower analog op amps with a microcontroller can monitor single battery cells and solar harvesters. Pairing up a 0.65 V/1 µA nanopower op amp with the low-power Cypress PSoC3 microcontroller and some simple external circuitry can yield a very low current measurement system, suitable for monitoring miniature power harvesting solar cells or a single-cell battery. The circuit operates on a few microamps at 1.8 V; optionally, the whole circuit can be self-powered from the source being measured. The op amps operate from voltages as low as 0.65 V and are connected directly to the cells; the PSoC3 microcontroller utilizes an internal boost regulator which operates from sources as low as 0.5 V.

App note: USB field firmware updates on MSP430 MCUs


TI’s application note: USB field firmware updates on MSP430 MCUs (PDF!)

With the advent of USB, end users can perform firmware upgrades in the field by simply attaching the device via USB and executing an application on the host PC. Such an approach has numerous advantages:

  • Problems discovered after product release can be fixed.
  • Reduced need for high-touch support, because problems can often be solved by instructing the user to upgrade firmware.
  • End users have a more positive experience with the product.
  • Product returns can be reduced.

The USB solution for MSP430™ microcontrollers has been designed to make this process simple and straightforward. The device contains a USB-based on-chip bootstrap loader, and TI provides a Windows source project for downloading firmware that can be quickly customized. This source can be built with Visual C++ 2008 Express, available from Microsoft at no cost. For the USB support software for MSP430 MCUs, see the MSP430 USB Developers Package (MSP430USBDEVPACK).

App note Quick-Start: Driving 14-segment displays with the MAX6954


Guidelines from Maxim on using the MAX6954 to drive 14-segment monocolor LEDs, app note here (PDF!):

This article is how-to guide, intended as a quick learning aid for engineers considering using the MAX6954 to drive 14-segment monocolor LEDs.

The MAX6954 is a versatile display driver, capable of controlling a mix of discrete, 7-segment, 14-segment, and 16-segment LED displays through a serial interface. This application note shows a typical application and configuration for driving eight mono-color, 14-segment LEDs.
See the MAX6954 data sheet for additional information about MAX6954 features.

App note: Using Cymbet™ EnerChip™ batteries instead of coin cells and super capacitors


High charge/discharge cycle and solid state reliability EnerChip from Cymbet make this a good replacement for super caps and coin cell backup batteries. Link here (PDF)

Primary and secondary (i.e., rechargeable) coin cell batteries, as well as super capacitors, have been in use for years as auxiliary power sources for applications including SRAM, real-time clocks, and microcontrollers. Now, a new type of rechargeable battery is available from Cymbet Corporation, the leader in thin film rechargeable micro-batteries.

App note: Battery fuel gauge IC (LC709203F) for 1-Cell Lithium-ion (Li+)


Lithium-ion fuel gauge IC from ON Semiconductors. Link here (PDF)

The LC709203F is an IC that measures the remaining power level of 1-cell lithium-ion (Li+) batteries used for portable
equipment etc.
This product reduces fuel gauge errors with a unique correction technology during measurement of battery temperature and
This technology has inherently high precision without the need for an external sense.

App note: Crystal oscillator basics and crystal selection for rfPICTM and PICmicro devices


The basics of crystals and crystal oscillators application note from Microchip, link here (PDF!)

This Application Note will not make you into an oscillator designer. It will only explain the operation of an oscillator in simplified terms in an effort to convey the concepts that make an oscillator work.
The goal of this Application Note is to assist the product design engineer in selecting the correct crystal and external capacitors required for the rfPICTM or PICmicro® device. In order to do this the designer needs a clear understanding of the interrelationship of the various circuits that make up an oscillator circuit. The product design engineer should also consult with the crystal manufacturer about the needs of their product design.

App note: Snubber capacitors for complete insurance of power semiconductors


An application note from WIMA about snubber capacitors, Link here.

The trend of modern semiconductor technology towards increasingly powerful applications results in the fact that switched currents and voltage levels are continuously increased and that simultaneously the switching speed is also increasing markedly.
The developments in the area of power semiconductors include the component group IGBT (Insulated Gate Bipolar Transistor) or IGBT modules.
The switching capacity with shortest switching times which can be realized using IGBTs necessitates an extremely low-inductance circuit design. Even the low self-inductance of the power bus may induce dangerous voltage overshoots between collector and emitter which may result in the destruction of the valuable power semiconductors.
To protect the components, so-called snubber suppressor circuits are used. The most important component in this respect is a low-inductance pulse capacitor in order to attenuate or cut off peak voltages.

App note: Selection of capacitors for pulse applications


Guidelines from WIMA about selecting capactiors for pulsed conditions. Link here

The maximum permissible AC voltage that can be applied to capacitors in sinusoidal waveform applications, can be determined from the graphs in the respective capacitor ranges.
However, where pulse conditions exists, the following procedure is to be observed to ensure that the correct capacitor rating is selected for a particular duty:
– Rated voltage
– Maximum current
– Dissipation
– Determining the permissible AC voltage and AC current at given frequencies