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Consider the following statements regarding 555 timer: 1. It operates on -5 V to +18 V supply voltage in both free running and one-shot modes. 2. It has a high current output and it can source or sink 500 mA. 3. The output can drive TTL and has a temperature stability of 80 parts per million (ppm) per degree celsius change in temperature or equivalently 0.008 %/°C. Which of the above statements are not correct?

Consider the following statements regarding 555 timer: 1. It operates on -5 V to +18 V supply voltage in both free running and one-shot modes. 2. It has a high current output and it can source or sink 500 mA. 3. The output can drive TTL and has a temperature stability of 80 parts per million (ppm) per degree celsius change in temperature or equivalently 0.008 %/°C. Which of the above statements are not correct? Correct Answer 1 and 2 only

Solution:

555 Timer IC:

  • The 555 timer chip is extremely robust and stable 8-pin device.
  • It can be operated either as a very accurate Monostable, Bistable or Astable Multivibrator to produce a variety of applications such as one-shot or delay timers, pulse generation, LED and lamp flashers, alarms and tone generation, logic clocks, frequency division, power supplies and converters etc.

 

Pin Diagram:

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Characteristics of 555 timer IC:

  • Typical operating voltage is +5V, can withstand a maximum of +18V.
  • The source/sink current of the output pin is 200mA.
  • Consumes up to 3mA when operating at +5V.
  • Trigger Voltage is 1.67 when operating at +5V.
  • Operating Temperature is 70 degree Celsius.
  • Available in 8-pin PDIP, SOIC, and VSSOP packages.

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