According to the property that the capacitor voltage will not change suddenly, the rising edge of Uc 1 will slow down, that is, the level of logic 1 will be moved back. 74HC 14 is an inverter with Schmidt input, and the two-stage series logic remains unchanged.
HC 14 is a high-speed CMOS device, and its pin 74HC 14 is compatible with low-power Schottky TTL(LSTTL) series. 74HC 14 follows JEDEC standard 7A. 74HC 14 has realized six Schmitt-triggered inverters, which can convert slowly changing input signals into clear and jitter-free output signals.
Until (1) reaches L, the potential of each point is reversed, and the charging current is reversed, thus repeatedly forming an impact. It can be seen that the oscillation frequency is determined by RC 1 R3 and C2 are difference channel active low, and the carry pulse is active high. RC3 is a high-level activated difference channel, and a low-level activated reset pulse.
HC 14 is a high-speed CMOS device. Its pins are compatible with low-power Schottky TT 1( 1STT 1) series, and a 6-channel Schmitt-triggered inverter is realized, which can convert slowly changing input signals into clear and jitter-free output signals. It can be applied to waveform, pulse shaper, unstable multivibrator, monostable multivibrator and so on.
What is the function of each pin in the 74HC 14D circuit diagram?
1 and hc 14 are Schmitt triggers with inverted outputs, and their inputs have hysteresis characteristics, which are mainly used for signal shaping. Two parallel connections are used to increase the output drive capability.
2.HC 14 is a 6-channel inverter. Input high level, output low level. Input low level, output high level. It's simple. No circuit diagram is needed.
3. The first sketch is the reset circuit. At the first power-on, the voltage across C 1 is zero, and the RST level is high. As C 1 is charged through R3, the potential at the RST terminal gradually drops to zero, and the single chip microcomputer starts to work. The lower part is the crystal oscillator circuit, which provides a fixed frequency clock for the single chip microcomputer.
4. Pin diagram is an intuitive view of the position and quantity of pins and the functions of pins in digital chips. Pin diagrams of chips are often used in digital circuit experiments.
5, carbon film, winding) Capacitors (electrolysis, polyester, porcelain, mica, inductance) It is really difficult to describe them for the first time. For example, sometimes, when a resistor is used in different positions, its function is different. We still have to make up the electronic circuit foundation.
6. The signal acquisition circuit adopts anti-logic, which improves the anti-interference ability. In addition, adding a pull resistor and a decoupling capacitor on the signal line can also stabilize the signal. The rest is basically an armchair strategist.
Find the function of each pin of 7404, the more detailed the better.
1, pin grounded, pin 9 Q2, pin 10 as the setting terminal of the second trigger, pin 1 1 as J2, pin 12 as K2, pin 13 as the clock pulse CP2 of the second trigger, pin/.
2. Release the audio. Multi-channel audio signal input, including stereo system input of two channels, selects the best different sound source signal input; Stereo system output; The treble and bass signals are controlled at 2 dB. The audio signal is controlled at 1 dB. Bidirectional loudspeaker attenuator.
3 and 4 are drivers. Simply put, the current allowed by the CPU pin is relatively small, and the current that the 7404 can pass is relatively large. If the current-limiting resistance is increased, that is, the current of LED is reduced, when the current is too small to pass through the pin of CPU without damaging CPU, then 7404 can be used.
4.LS74 double-D flip-flop function: used to form a counter, a frequency divider, a digital register, a shift register and a program controller.
5. the content is large. In short, the design of buffer/line driver improves the performance of tri-state buffer and the layout density of PCB.