2025 Component Abuse Challenge: Pushing A 555 To The Limit
The humble 555 timer dates back to the early 1970s as the NE555, a bipolar integrated circuit. Over time, it has evolved into a range of variants, including dual versions and CMOS-based models. These improvements have aimed to enhance the chip's capabilities.
[translate:MagicWolfi] has been exploring just how fast an astable 555 can operate. The Microchip MIC1555 is the latest in the series, featuring a 5-pin CMOS SOT-23 package that removes the frequency control and discharge pins found in the original.
Despite this, the MIC1555 remains quite versatile and is an excellent candidate for oscillator experiments. Various capacitor and resistor values were tested across the supply voltage range in an astable setup.
The chip is officially rated for a maximum frequency of 5 MHz, but with a zero Ohm resistor and only the parasitic capacitance of an open circuit, it achieved an impressive 9.75 MHz. This result might be unexpected, as the chip is not typically chosen for ultra-high-speed operation.
We like it that someone’s managed to tie in the 555 to the contest, and given that it still has a few days to run at the time of writing, we’re hoping some of you might be inspired to enter one of your own.
The 2025 Component Abuse Challenge highlights how classic ICs can still surprise when pushed beyond their typical limits.
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