Substitution rules for nonvolatile memory components: This article explains basic guidelines for substituting a nonvolatile (NV) memory component in an existing design.
Category Archives: app notes
App note: Overvoltage protection for amplifier outputs
rsdio writes: this circuit includes one of my favorites: a dual, common-cathode diode package To protect audio amplifiers and other automotive electronic circuits in the event of an accidental direct connection to the car battery voltage, add the circuitry shown (a shunt regulator, diodes, and an n-channel MOSFET in series with each audio path).
MAX11835 haptic actuator controller with I2C interface
rsdio writes: Haptics and Capacitive Touch are hot topics about which I would like to learn more. Industry’s First Single-Chip Haptic Pattern Generator, Boost Converter, and Driver IC for High-Voltage Actuators Flexibility: designed to drive single-layer piezo actuators, multilayer piezo actuators, or electroactive polymer actuators allowing customers to choose between the various types of haptic […]
PWM controller for low noise power supplies
rsdio writes: These parts look promising on paper, but the sample circuit has too many parts for an inexpensive implementation. I’m still sure something can be learned by studying the data sheets. MAX5975A, MAX5975B Current-Mode PWM Controllers with Frequency Dithering for EMI-Sensitive Power Supplies: High Efficiency at Light Loads Meets Green Requirements of Next-Generation IP […]
App Note: wireless home security implementing KEELOQ® and PIC®
KEELOQ® is an authentication system designed by Microchip. It’s based on a proprietary, non-linear encryption algorithm that creates a unique transmission on every use, supposedly rendering RF replay attacks useless. The algorithm uses a programmable 64-bit encryption key unique to each device to generate 32-bit hopping code. In this new app note, Microchip presents a […]
App note: Dynamic siphon steals current from USB port
rsdio tipped us to an app note on USB-port power: Very cool! This is like an audio ducking compressor for voiceovers, but for charging. This circuit exploits all the power available from a USB port by dynamically adjusting the amount of current delivered to the load, thereby siphoning a relatively constant (and maximum) current from the […]
Introduction to the Controller Area Network (CAN)
A controller area network (CAN) is ideally suited to the many high-level industrial protocols embracing CAN and ISO-11898:1993 as their physical layer. Its cost, performance, and upgradeability provide for tremendous flexibility in system design. This application report presents an introduction to the CAN fundamentals, operating principles, and the implementation of a basic CAN bus with […]
Low-noise rail-to-rail op-amps extend battery life
rsdio writes: These are potentially overkill for most DIY, but if you really need small size, low noise, and/or rail-to-rail performance, then they might be just the ticket. Probably a great choice for a DSO front end. With low power, particularly USB 5 V, rail-to-rail capabilities can be really important. Low-Noise, CMOS-Input, Rail-to-Rail Op Amps […]
App note: Automotive power circuit handles interruptions and 72volt spikes
rsdio writes: More good ideas to steal and repurpose This circuit maintains power to the load regardless of momentary shorts or opens in the supply voltage, and includes a low-current overvoltage-protection IC (MAX6495) that protects the load against transient voltages up to 72V.
App note: Simple high-voltage supply
rsdio tipped us to an app note on power-supply circuits: more food for the OpenBench Power Supply project – note the floating output This circuit includes magnetic isolation that allows you to configure a positive, negative, or floating output. The floating output is enabled by a separate winding that generates a feedback voltage proportional to, […]
App note: High-side, current-sense amplifiers with 12-bit ADC and op amp/comparator
Another article that might help with bench power supply designs: Current-Sense Amplifiers with Digital Output and 60V Common-Mode Range Offers easy interface with microcontrollers (supports 1.8V logic) by using digital outputs Delivers wide 60V common-mode range for robustness under fault conditions Includes internal op amp/comparator that allows flexibility in system design: the internal amplifier can […]
App Note: Analog switch multiplexes SFP modules
rsdio writes: There is probably a way to implement this circuit with any analog mux instead of the Maxim part… Analog Switch Multiplexes SFP Modules To avoid multiple I²C bus masters in a telecom or data-communications system with SFP modules, add an analog multiplexer (MAX4572) that directs the data line to the appropriate SFP module.
App Note: Isolated power using capacitors
rsdio tipped us to an app note on isolated power-supply circuits: Wow! It’s quite interesting to see how to substitute capacitors for a transformer. Without digging deeper, though, it’s not clear whether voltage boost can be achieved. An integrated H-bridge driver for isolated power-supply circuits (MAX256) usually drives the primary of a transformer, but it […]
App note: Simple circuit limits amplifier output
rsdio writes: This is a strange one. It claims to prevent clipping, but still appears to introduce distortion. Perhaps the idea is that soft clipping is preferred to hard clipping? If there were a voltage-controlled gain input, then true peak limiting would be possible, but this seems to trade one form of distortion for another. […]
High-voltage transmit/receive switches
rsdio writes: These chips look highly flexible for interfacing between different voltage logic circuits MAX4936, MAX4937, MAX4938, MAX4939 Octal high-voltage transmit/receive switches Integrated T/R switches significantly reduce component count while reducing power Integrated solution reduces system component count, saving space and improving system reliability Consumes less system power, allowing design flexibility in ultra-portable applications Integrated […]
App note: SMBus-programmable battery chargers
rsdio writes: SMBus is similar to I2C, and should therefore be easily connected to most PIC or AVR projects. Highly integrated, 850kHz/500kHz SMBus-programmable battery chargers: MAX17435/MAX17535, highly integrated SMBus™ battery chargers capable of operating at 850kHz and 500kHz, respectively. Unlike competitive solutions, MAX17435/MAX17436 allow the charge setting to be programmed via the SMBus interface, eliminating […]
App note: Control high-voltage LEDs with low-voltage pins
rsdio writes: Although this circuit does not directly show how, you can use the same idea to make a 3.3 V tolerant I/O pin control an LED with a much higher voltage. The caveat is that all of the current still passes through the I/O pin, but at least you can control several LEDs in […]
25A 14V step-down regulator with integrated FETs
McZ writes in with an impressive step-down regulator: The TPS56221 is a high-efficiency synchronous switcher with integrated FETs, which achieves a power density of greater than 200W/in3 with greater than 90 percent efficiency at high loads. The easy-to-use SWIFT step-down regulator supports 25-A point-of-load designs for telecommunications, networking and other applications.
App note: Low-cost circuit converts clock to low-distortion sinewave
rsdio writes: nothing beats a pure sine wave oscillator, except another pure sine wave oscillator at a similar frequency: This circuit derives a pure sinewave from a crystal-controlled clock source by using a ring counter to remove the highest-amplitude unwanted harmonics, and filtering the result with an 8th-order lowpass, switched-capacitor elliptic filter (MAX7400).
App note: developing embedded graphics applications with PIC® MCUs with integrated graphics controller
Microchip has a new application note for developers designing their first MCU graphics related application. It describes the definitions and terms relating to graphics applications, and discusses the theory, necessary decision factors, hardware considerations, available microcontrollers and development tools. This is a fairly comprehensive doc, starting out with the basics and moving quickly to complex […]