App note: Core independent voltage window signal detection using a single comparator


Presenting the usage of Core independent paripheral of PICs in this app note from Microchip. Link here (PDF)

It is possible to find out whether a measured signal is below or above a certain value/reference using a single comparator. But, what if the desired interval is between two values, the undervoltage and overvoltage protection?

The most convenient and fastest solution is to use two comparators and two references. The results are analyzed to decide which of the three intervals houses the measured signal. Using an Analog-to-Digital Converter (ADC) and core post-processing will yield the same result, but the process is slower and dependent on core availability.

App note: Power supply rejection ratio of low dropout voltage regulators


Here’s an app note about PSRR of LDO from Microchip. Link here (PDF)

The Power Supply Rejection Ratio is the ability of a device, such as a Low Dropout Voltage regulator, to reject the various perturbations that can be found in its input supply rail by providing a greatly attenuated signal at the output. Generally, the main source of the perturbation will be the output ripple of the DC/DC converters that typically power LDOs.

High PSRR LDOs are recommended for powering line ripple sensitive devices such as: RF applications, ADCs/DACs, FPGAs, MPUs, and audio applications.

One important clarification must be made: PSRR is NOT the same with output noise. PSRR is a measure of rejection. It shows what the part will output based on the given input.

App note: Passive entry door system with proximity sensor


A full implementation of a keyless entry from Microchip. Link here (PDF)

The door access systems have evolved from simple physical keys to more sophisticated keyless entry systems. Now, we have a system that automatically unlocks the door when user carrying an access key approaches the door handle. As it does not require any user action this system is referred to as Passive Entry

App note: Low Power POE Flyback Converter


App note from Microchip about their MIC2145 boost switching regulator to do POE Flayback conversion. Link here (PDF)

The MIC2145 skip mode controller is used to implement a flyback converter that is intended for use in nonisolated, low power, POE applications. The circuit has a nominal 48V input and supports the POE voltage range of 36V to 57V. The output voltage is 2.5V at 350mA.

App note: Adding flexibility by using multiple footprints for I2C™ serial EEPROMs


Save PCB space by utilizing EEPROM SOIC-8 area, here’s an application note from Microchip. Link here (PDF)

For many years, the 8-lead SOIC package has been the most popular package for serial EEPROMs, but now smaller packages are becoming more commonplace. This offers a number of benefits; the reductions in footprint size and component height are some of the more obvious ones. Smaller packages also generally offer a cost advantage over their larger counterparts.

App note: Writing to flash and EEPROM on the tinyAVR 1-series


Update your tinyAVR code to access memories when using 1-series tinyAVRs. Link here (PDF)

On tinyAVR® 1-series devices, access to Flash memory and EEPROM has been changed from that on previous tinyAVR devices. This means that existing code for writing to Flash and EEPROM on older devices must be modified in order to function properly on tinyAVR 1-series devices. This application note describes what has changed and how to adapt code to these changes.

App note: Grid-connected solar microinverter reference design


A good read from Microchip on the theory behind inverter design connected to grip power. Link here (PDF)

There are two main requirements for solar inverter systems: harvest available energy from the PV panel and inject a sinusoidal current into the grid in phase with the grid voltage. In order to harvest the energy out of the PV panel, a Maximum Power Point Tracking (MPPT) algorithm is required. This algorithm determines the maximum amount of power available from the PV module at any given time. Interfacing to the grid requires solar inverter systems to abide by certain standards given by utility companies. These standards, such as EN61000-3-2, IEEE1547 and the U.S. National Electrical Code (NEC) 690, deal with power quality, safety, grounding and detection of islanding conditions.

App note: Multiple Capture/Compare/PWM (MCCP): Extending the functionality for low-cost motor control applications


Microchip’s MCCP module on PIC32 devices demonstrate the built-in majority detection filter for simpler motor control drives. Link here (PDF)

The motor control industry has been focusing on designing low-cost motor control drives for various applications. The consumer demand for low-cost motor control applications is driving this trend.

Microchip has recently introduced the PIC32MM family of microcontrollers, which is capable of addressing the low-cost motor control requirements. The low-cost solution benefits from the capability of the Multiple Capture/Compare/PWM (MCCP) module available in Microchip’s PIC32MM controllers. This document
illustrates the usage of the MCCP module in the PIC32MM0064GPL036 controller, from Microchip Technology, to deliver a development platform for motor drive applications.

MCCP implementation, similar to the motor control solution discussed in this document, can also be extended to Microchip’s PIC24 and dsPIC33 family of devices which feature MCCP.

App note: IR remote control transmitter


IR remote control transmitter application note (PDF!) from Microchip:

This application note illustrates the use of the PIC10F206 to implement a two-button infrared remote controller. The PIC10F2XX family of microcontrollers is currently the smallest in the world, and their compact sizes and low cost make them preferable for small applications such as this one.
Two example protocols are shown. The first is Philips® RC5, and the second is Sony™ SIRC. These two protocols were chosen because they are fairly common and their formats are well documented on professional and hobbyists’ web sites. They also demonstrate two differing schemes for formatting the transmission.

App note: Using the Configurable Logic Cell (CLC) to interface a PIC16F1509 and WS2811 LED driver


An application note (PDF!) from Microchip on how to use CLC to interface a PIC16F1509 and WS2811 LED driver:

The Configurable Logic Cell (CLC) peripheral in the PIC16F1509 device is a powerful way to create custom interfaces that would otherwise be very difficult. One example is the single-wire PWM signal, used by the WS2811 LEDs, well known in LED video display systems. This application note will provide a simple demonstration of a WS2811 LED Strip driver.