The right clock frequency for every radio chip
Depending on the radio IC used, LPWAN applications require MHz-rated crystal oscillators operating at 24 MHz, 32 MHz, 38.4 MHz, 39 MHz, 40 MHz, 48 MHz, 50 MHz or 52 MHz. Many applications also use a 32.768 kHz crystal oscillator as a real-time clock for sleep mode, during which battery-powered LPWAN devices spend the majority of their service life.
MHz crystal oscillators to suit the module size
- SMD03025/4: Ceramic package 3.2 x 2.5 mm, 4 pads
- SMD02016/4: Ceramic package 2.0 x 1.6 mm, 4 pads
- SMD01612/4: Ceramic housing 1.6 x 1.2 mm, 4 pads
- SMD01210/4: Ceramic case 1.2 x 1.0 mm, 4 pads
32.768 kHz resonant crystals
- M3215RR: Ceramic case 3.2 x 1.5 mm, 2 pads, ESR max. 50 kΩ
- M2012: Ceramic package 2.0 × 1.2 mm, 2 pads
- M1610: Ceramic package 1.6 x 1.0 mm, 2 pads
Our design recommendation: compact for MHz crystals, LOW ESR for kHz crystals
The M3215RR combines a very low ESR of max. 50 kΩ with the most competitive price amongst miniaturised 32.768 kHz resonators. Developers can therefore save space most effectively and cost-efficiently with MHz-range crystals: We recommend a small LRT crystal for the radio chip in combination with the M3215RR.
This recommendation has proven its worth in the designs we have supported. A crystal from the SMD01612/4 or SMD02016/4 is used in conjunction with the M3215RR . In our experience, this combination achieves the greatest reduction in system power consumption.
Fast and reliable oscillation thanks to LRT
Our MHz and kHz resonant crystals are based on the exclusive LRT design (Low ESR Resonator Technology). The very low resonant resistances ensure that the crystals oscillate very quickly and very reliably within the circuit. The oscillator requires less amplification, the radio chip wakes up more quickly, and each transmission and reception cycle consumes less energy. For battery-powered LPWAN devices, this means a longer operating time.
Design-in support
Are you developing an LPWAN module? Our timing specialists will assist you in selecting the appropriate crystal oscillator, sizing the load capacitances and verifying start-up reliability. Please get in touch.
