Behavioural mixed-signal modelcrystal
Crystal
Quartz crystal between the oscillator pins of a chip (OSC_IN / OSC_OUT), with two load capacitors to GND. A chip whose oscillator pins are wired to it starts its crystal oscillator at the crystal frequency; without it the oscillator does not start. In the circuit the crystal shows as its shunt capacitance. 3225 package: four pads, 2 and 4 are the metal lid (GND).
Key data
- Category
- Passive
- Simulation model
- Behavioural mixed-signal model
- Reference prefix
- Y
- Pins
- 3
- Land pattern
- Crystal_SMD_3225-4Pin_3.2x2.5mm
Simulation model
A behavioural model implements the interface of the chip (registers, protocol, timing) at its pins. The pins are connected to the analog circuit like CMOS pins.
- Model
- crystal
- Supply pins
- G / G
Pins 3
| Pin | Name | Use |
|---|---|---|
| 1 | 1Passive pin | Contact: carries a signal or supply wire |
| 3 | 2Passive pin | Contact: carries a signal or supply wire |
| G | GNDGround pin | Ground |
Parameters 4
Frequency
fDefault24M Hz
HSE of the STM32MP1: 24 MHz; LSE (real-time clock): 32.768 kHz
Load capacitance
CLDefault8p F
from the crystal data sheet; each load capacitor ≈ 2 × (CL − stray capacitance ≈ 2–5 pF)
Shunt capacitance
C0Default2p F
capacitance of the electrodes and package (data sheet: C0)
Package
packageDefault3225
32252012
PCB
Verified land pattern
Crystal_SMD_3225-4Pin_3.2x2.5mm| Package | Land pattern | Status | Source |
|---|---|---|---|
| 3225 · NX3225SA-24.000M | Crystal_SMD_3225-4Pin_3.2x2.5mm | Verified land pattern | KiCad 10.0.7: symbol Device:Crystal_GND24, footprint Crystal:Crystal_SMD_3225-4Pin_3.2x2.5mm; 24 MHz SMD crystal, 3.2 × 2.5 mm, pads 2/4 = lid |
| 2012 · ABS06-32.768KHZ | Crystal_SMD_2012-2Pin_2.0x1.2mm | Verified land pattern | KiCad 10.0.7: symbol Device:Crystal, footprint Crystal:Crystal_SMD_2012-2Pin_2.0x1.2mm; 32.768 kHz tuning-fork crystal, 2.0 × 1.2 mm, no lid pad |