This chart shows the performance matrix between current consumption and frequency stability over temperature. Red outlined AT-cut MHz crystal should consume more power compared to kHz range devices. The “ST3215”, as a tuning fork crystal, and the “KC3215” as a clock oscillator are the most power-saving devices, but their stability is rough. The “KT3225T” as a TCXO, and the “KR3225Y” as real time clock oscillators have tight frequency stability performance with low power consumption.