AEC-Q200 qualification and temperature grade
The ECS-120-8-33Q-RES-TR: The ECX-33Q series crystal carries AEC-Q200 qualification — the stress-test grade that gates automotive under-hood and chassis-domain electronics. The 12 MHz fundamental frequency is a common microcontroller clock source; the ±15 ppm initial tolerance and ±50 ppm stability over temperature keep the UART baud-rate error below 0.5 % across the full automotive temperature window.
Package footprint and board integration
The 3.20 mm by 2.50 mm body with a 0.80 mm seated height sits below the typical keep-out zone for microcontroller clock crystals on dense automotive boards — the four-pad no-lead SMD package avoids through-hole clearance and works with standard reflow profiles. Load capacitance is specified at 8 pF; the MCU-side trim caps and trace parasitics need to sum to this value for the advertised tolerance to hold on the assembled board. ESR is listed at 100 Ω, which is unremarkable for a 12 MHz fundamental-mode crystal and does not constrain drive level from a typical MCU oscillator circuit.