32 MHz fundamental crystal — ECS-33B series
The ECS-320-10-33B-CKM-TR is a 32 MHz fundamental-mode quartz crystal in the 4-SMD no-lead package, rated 10 pF load capacitance and ±10 ppm combined frequency tolerance and stability.
What ±10 ppm means for your clock budget
±10 ppm total frequency deviation (tolerance plus stability) translates to a worst-case timing error of 0.001 % — at 115200 baud UART, a ±10 ppm crystal introduces less than 0.12 baud error per second, well within the ±2.5 % UART tolerance window. For any MCU clocking scheme that derives baud rates from the same crystal, the combined tolerance budget matters more than either spec alone. ESR is listed at 40 Ω — at 32 MHz fundamental this is well within the drive-level capability of typical MCU oscillator circuits. A higher ESR crystal in this frequency range would require more drive power from the oscillator circuit, increasing startup time and risking premature AT-cut aging; 40 Ω keeps the motional resistance within the comfortable range for CMOS inverter Pierce oscillators.
Package and board-fit checklist
The 0.031-inch profile clears standard SMD reflow profiles without special thermal management; no board-level redesign is required if the existing crystal pad openings and paste mask match the footprint. Operating temperature is -20 °C to 70 °C — commercial grade, appropriate for consumer electronics, office equipment, and indoor instrumentation. This temperature band excludes automotive or outdoor-exposed deployments without a thermal enclosure; the ECS-33B is not an industrial-temperature or AEC-Q qualified part.