App note: Ceramic input capacitors can cause overvoltage transients

This app note from Linear Technology describes why ceramic capacitors aren’t an ideal replacement for tantalum based caps. The higher internal inductance of ceramic capacitors creates high voltage spikes: Applying a voltage step to a ceramic capacitor causes a large current surge that stores  energy in the inductances of the power leads. A large voltage […]

App note: Minimizing switching regulator residue in linear regulator outputs

Here is an app note from Linear Technology describing how to minimize switching regulator noise in linear regulator outputs. Linear regulators are commonly employed to post-regulate switching regulator outputs. Benefi ts include improved stability, accuracy, transient response and lowered output impedance. Ideally, these performance gains would be accompanied by markedly reduced switching regulator generated ripple […]

App note: 2-wire virtual remote sensing for voltage regulators

Here is an app note from Linear Technology describing the use of virtual remote sensing of wiring voltage drops in power supply designs. Here, the LT4180 Virtual Remote Sense™ (VRS) IC alternates output current between 95% and 105% of the nominal required output current. The LT4180 forces the power supply to provide a DC current […]

App note: Bridge circuits

Another app note from Jim Williams and Linear Technology [PDF!], describing  various bridge circuits. Bridges described here are mostly made of passive components, and should not be confused with bridge motor drivers. Bridge circuits are among the most elemental and powerful electrical tools. They are found in measurement, switching, oscillator and transducer circuits. Additionally, bridge […]

App note: Using LT5400 high precision resistor neworks in high precision analog designs

  Here is a design note from Liner Technology explaining how using their LT5400 matched resistor networks in your analog design can improve it’s precision by an order of magnitude. The actual performance of precision amplifiers and ADCs is often difficult to achieve since data sheet specifications assume ideal components. Carefully matched resistor networks, such […]

App note: Using High-Side NMOS drivers

Here is an app note describing how and why to use NMOS transistors for high-side switching operations, and how to implement it using associated drivers. At first glance, P-channel MOSFETs appear to be the natural choice for high side switching. Unfortunately, the RDS(ON) exhibited by most P-channels is prohibitively high.(Mother Nature has decreed that electron […]

App note: Using the LTM2881 as an Isolated 5V power supply

Here is an app note from Linear Technology on how to use their LTMM2881 isolated RS485 transceiver as a isolated 5v power supply. The LTM®2881 is an isolated RS485 transceiver that guards against large ground-to-ground differentials. An onboard DC/DC converter provides isolated 5V power to the output.

App note: Useful analog circuits for digital systems

Here is an oldie, but a goodie. The late analog guru Jim Williams describes lots of analog circuits that were used in digital systems. Most of these are now integrated into digital ICs, some are still in use today. The pristine, regimented symmetry of  digital circuit boards is occasionally interrupted by an irregular huddle of […]

App note: Switching regulators for poets

The basics of SMPS design, written by the late analog guru Jim Williams: A problem is that while everyone agrees that working switching regulators are a good thing, everyone also agrees that they are difficult to get working. Switching regulators, with their high efficiency and small size, are increasingly desirable as overall package sizes shrink. […]

App note: Thermocouple measurement

Last week we wrote about a Maxim app note about high precision temperature measurement with thermocouples. At Jim’s request we found a more in-depth intro to thermocouples. This app note from Linear Technology covers everything you ever needed to know about thermocouples. Learn how thermocouples were discovered, and how to build very elaborate and highly […]

App note: Acoustic thermometry

Orcinus tiped us about this interesting app note on acoustic thermometry from Linear Technology: People usually measure temperature in order to correct the distance determined using ultrasonic transducers. Acoustic thermometry takes the opposite approach – the distance is fixed and the time it takes for an acoustic pulse to make a round trip is used […]