What the 32.768 kHz frequency means for RTC design
The ECS-.327-12.5-34S-TR: This is a tuning fork crystal running at 32.768 kHz in fundamental mode — the standard frequency for real-time clock (RTC) circuits because 2^15 cycles equal exactly one second, making binary counter division clean and low-power. The ±20 ppm frequency tolerance at 25 °C translates to roughly ±1.7 seconds per day — acceptable for timekeeping in battery-powered microcontrollers, smart sensors, and industrial control boards where the RTC runs from a backup coin cell or supercapacitor when the main supply drops. Load capacitance is 12.5 pF and ESR is 70 kΩ — both values need to match the oscillator circuit on the host MCU; mismatched load capacitance shifts the actual oscillation frequency and accumulates timing error over temperature.
Package and production assembly
Supplied on tape-and-reel or cut tape — reels are the standard format for SMT pick-and-place lines; confirm the feeder pocket size matches the production tool before committing a new reel to the line.
Temperature grade and deployment environment
Rated -40 °C to 125 °C — the upper limit covers the full automotive under-hood and industrial control enclosure temperature band, making this suitable for dashboard ECUs, engine-management sensor nodes, and motor-drive control boards that see extended high-temperature operation.
