RU1687003C - Quartz generator - Google Patents

Abstract

The invention relates to electronic devices and can be used in electronic watches. The goal is to increase the stability of the amplitude of the output oscillations. The crystal oscillator contains p-channel MOS transistors (T) 1. 2. 3, p-channel T 4, 5. 6. 7, 12. quadrupole 8 feedback with a quartz resonator E, capacitor 10, resistor 11 , bias source 13. By selecting the geometry of T b and 12 at the gates T k, 5,6,7 and 12, voltage U / 2 is generated. At that, T k and 5 open. respectively, T 1 and 2 open, which provides a reliable start. As the operating points T 4 and 5 approach the threshold values, the rate of change of the bias voltage decreases due to an increase in the resistance of the channel T 12. Due to this, the point of dynamic equilibrium does not depend on the spread of parameters T. Under the influence of destabilizing factors, dynamic equilibrium is determined by charge-discharge of the capacitance formed by the series connection of the capacitor 10 and the capacitor of the four-port terminal B with a quartz resonator 9. This combination of functions additionally reduces the the spares occupied by the integrated circuit chip. 1 wp 1 ill. next to

Description

The invention relates to electronic devices and can be used in electronic watches.

The purpose of the invention is to increase the stability of the amplitude of the output oscillations.

The drawing shows a structural electrical diagram of a crystal oscillator.

The crystal oscillator contains the first, second, and third n-channel MOS transistors 1, 2, 3, the first, second, third, and fourth. P-channel MOS transistors 4.5, 6.7, and a four-terminal feedback loop 8 quartz resonator 9, capacitor 10, resistor 11, fifth p-channel MOS transistor 12, bias source 13.

A crystal oscillator operates as follows.

By selecting the geometry of the n-channel MOS transistor 3, the p-channel MOS transistors 6. 12, the voltage Un / 2 is generated at the gates of the p-channel MOS transistors 4, 5, 6. 7. 12. In this case, the p-channel MOS transistors 4, 5 open. Accordingly, n-channel MOSFETs 1,2 open. This ensures a reliable start of the crystal oscillator. .

Starting conditions are provided at a supply voltage exceeding the largest of the threshold voltage of the transistors, significantly lower than the sum of the threshold voltage of the transistors. Fourth

The R-Closed MOSFET 7 is opened only when the voltage level is reached at the source of the second R-channel MOSFET II. The value is the same as the voltage of the fourth R-channel MOSFET 7. Due to this, the fast start is ensured. determined only by the steepness of the first n-channel MOS transistor and the first p channel MOS transistor 4 and the parameters of the elements of the four-terminal 8 with a quartz resonator 9. When the voltage difference from the gate and the drain of the second p-channel MOS transistor 5 reaches the threshold value of the voltage of the fourth p-channel MOSFET 7 last opened. The second r-channel MOS transistor 5 is also open at this moment, therefore, the channels of the r-channel MOS transistors 7 and B bypass the third r-channel MOS transistor b, as a result of which the voltage across the gates of the first, second, third, and In addition, the p-drop MOSFETs 4,5, b, 12 increase, and the potential of the lower plate of the capacitor 10 decreases. The shunting of the channel of the third p-channel MOS transistor 6 increases with increasing amplitude of oscillations, as a result of which the voltages at the gates of the p-channel MOS transistors 4, 5, C, 12 decrease, gradually approaching their threshold voltages. The first and the third p-channel / MOS transistors of mountains 1, 3 together with the first and fifth p-channel MOS transistors 4, 12 form current mirrors, therefore, when connecting the source of the p-ka-aliologi MOS transistor 12 to the power bus on the gates of the first and second r-channel MOS-transistorosis 4, B installed threshold voltages are set. The conductivity of the first p-channel MOSFET 4 decreases, the voltage across the first n-channel MOSFET f decreases, tending to its threshold voltage. Similarly, the gate voltage of the second n-channel MOS transistor 2 tends to a threshold value. If the geometry of the fourth and fifth p-channel MOS transistors 7, 12 is correctly selected, the operating points of the first and second p-channel MOS transistors 1.2 h of the first and second r-channel MOS transistors 4, 5 in stationary mode, there will be p near-threshold regions of volt-ampere characteristics, providing high efficiency. The use of control over the source circuit of the fifth p-channel MOS transistor 12 eliminates the possibility of workers being exact in the cutoff region, which is possible due to the overthrow of threshold voltages and specific Irutility. As the working points of the first and second p-channel MOS transistors 4, 5 approach the threshold values, the rate of change

The bias voltage decreases due to an increase in the channel resistance of the fifth p-channel MOS transistor 12. Due to this, the point of dynamic equilibrium of the oscillatory system is high

accuracy and with a sufficiently powerful fourth p-channel MOS transistor 7 does not depend on the spread of its parameters. When exposed to destabilizing factors, for example, a decrease in supply voltage.

the dynamic equilibrium of the system is determined by the charge-discharge of the storage capacitor, the functions of which are performed by the capacitance formed by the series-connected capacitor 10 and the four-terminal capacitor 8. Such a combination of functions additionally reduced the area occupied by the integrated circuit chip.

The gate voltage of the third p-channel MOSFET 3 is set either by the source 13 or by the voltage of the power bus.

FORMULA AND SECTION

Claims (1)

1. A crystal oscillator containing the first, second and third n-channel MOS transistors of the mountain, the sources of which are connected to the common bus, the first, second and third r-channel MOS transistors, the sources of which are connected to the power bus, the fourth channel transistor, the source of which is connected to the drains a high-voltage p-channel MOS transistor and a second p-channel MOS transistor, a four-terminal feedback loop that is connected between the gate and the drain of the first p-channel MOS transistor, a resistor whose first output is connected to the drains of the first p-channel MOS transistor and first of p-channel MOS transistor and the second terminal of which is connected to the gate Perot p-channel MOS transistor, a capacitor which is connected between the gate of the first p-channel MOS transistor and a first n-MOS transistor kanelnogo, wherein the gate of the second p-channel MOS transistor is connected to the gate of the first p-channel MOS transistor, so that and, in order to increase the stability of the amplitude of the output oscillations. introduced the fifth r-channel MOS transistor, the gate of which is connected to the gates of the first, second, third and fourth r-channel MOS transistors, the source of the fifth r-channel MOS transistor is connected to the drains of the third and four r-channel MOS transistors transistors, and the drain of the first p-channel MOSFET is connected to its gate and to the drain of the third p-channel transistor, the gate of the third n-channel MOS transistor is connected to the power bus. 2 The generator according to claim 1. that the gate of the third p-channel MOSFET is connected to the pit bus through an additional bias source. G I L 3L g IL. 8