CMOS RC Timer, MIC1555YM5, Breakout Module

The Meridian MIC1555 breakout brings a compact CMOS timer onto five 0.1-inch-spaced header connections, making it easier to build timing circuits on a breadboard without working directly with the tiny SOT-23 package. Use it to generate a single timed pulse in monostable mode, or a repeating square wave in astable mode. External resistors and capacitors set the timing, so you can choose the pulse duration or oscillator frequency to suit your project. No microcontroller or code is required to generate the waveform. The board includes 100 nF and 10 µF supply-decoupling capacitors and a power indicator LED. The external timing resistor and capacitor are not included; add these using the example circuit or your own calculated values. The MIC1555 is similar in function to a classic 555 timer, but it is not a pin-compatible replacement. It has separate trigger and threshold inputs and no dedicated discharge pin. Follow the MIC1555 wiring diagrams in this guide rather than a standard eight-pin 555 circuit. Start with the oscillator example to build a simple square-wave generator. The optional Arduino sketch measures the output—it does not control the timer. Happy building!