Oscillator is one of the important passive components in electronic circuits that select specific frequencies through the piezoelectric effect of quartz crystals to provide a stable frequency signal. However, if the circuit using the crystal oscillator is affected by temperature, it will also interfere with the normal operation of the crystal oscillator, causing the frequency in the circuit to fluctuate, causing circuit failure. To improve this problem, the Temperature Compensated X-tal Oscillator (TCXO) came into being. It uses a compensation circuit consisting of NTC thermistors, capacitors, and fixed resistors to offset the deviation of the oscillation frequency caused by temperature changes to ensure the stability of the frequency signal in the circuit.
The compensation circuit of the temperature compensated crystal oscillator and the quartz crystal oscillator in the oscillator are connected in series, when the temperature changes, the NTC thermistor can sensitively sense and send a signal in the circuit in the form of resistance value change, thereby causing the corresponding change in the equivalent series capacitor capacitance of the quartz crystal, thereby effectively canceling or reducing the drift rate of the oscillation frequency due to temperature change.
In order for the crystal oscillator to work continuously and smoothly, to ensure that the crystal resonance characteristics and the stability of the circuit frequency signal are maintained in a wide temperate range, the NTC thermistor in the compensation circuit is required to have high sensitivity, high accuracy and good reliability. SMD chip NTC thermistor of EXSENSE Electronics Technology Co., Ltd. meets the needs of crystal oscillators, and its high sensitivity can respond in time, so that the oscillator can also respond quickly when the temperature changes; It has good consistency and can assist the crystal oscillator to operate stably.