What components are inside the input module of the MC12079 IC for UHF division?

In summary, the individual is experiencing oscillation issues with their MC12079 IC used as a UHF divider by 256. They have inserted a 47 k resistor between the non-inverting input and ground to correct the problem, but are unsure of any potential consequences on other parameters. They are also curious about the components inside the input module and if the resistor may have unintended effects. The discussion also touches on layout issues and the presence of op amp inputs and load resistors.
  • #1
Ravaner
134
3
Hello. I use a MC12079 as UHF divider by 256. Unfortunately this IC was oscillating at about 10 MHz. To correct this problem I insert a 47 k resistor between non inverting input and Gnd as Inverting input is used for signal to divide. It works, but I would like to know if this can have unwanted consequence on other parameters for example sensitivity. My question : has someone a precise idea of what is inside the input module ( in+ & in-) just in front of 1st flip-flop ( detail schematics) ?
 
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  • #2
You put the resistor in parallel with the capacitor?

Can you post schematic?
What is the input freq and amplitude?

What do you mean "oscillating at 10MHz"? Is the output 10MHz superimposed on the intended RF, or is it just outputting 10MHz?
Is the 10MHz oscillation full power or at a small parasitic level.

Sounds to me like you may have a layout issue, I would not feel comfortable applying the 47K fix not knowing the root cause of the problem.
 
  • #3
Hi. Oscillation occurs even with unconnected signal imput. I made several tentatives to join schematics pic but unsuccessfully ! Sorry
 
  • #4
Ravaner said:
Hello. I use a MC12079 as UHF divider by 256. Unfortunately this IC was oscillating at about 10 MHz. To correct this problem I insert a 47 k resistor between non inverting input and Gnd as Inverting input is used for signal to divide. It works, but I would like to know if this can have unwanted consequence on other parameters for example sensitivity. My question : has someone a precise idea of what is inside the input module ( in+ & in-) just in front of 1st flip-flop ( detail schematics) ?
Seems to have an op amp input. The data sheet shows a 1.2k resistor load between output and ground. The non inverting input has a 50 ohm load resistor. Wondering if you have these in place, obviously with very short connections?
 

Related to What components are inside the input module of the MC12079 IC for UHF division?

1. What is the internal structure of MC12079?

The MC12079 is a type of integrated circuit (IC) that is used in electronic devices. It is made up of several layers of different materials, including silicon, metal, and insulating materials. The internal structure of the MC12079 includes transistors, resistors, and capacitors, which are all connected in a specific way to perform a particular function.

2. How does the internal structure of MC12079 affect its performance?

The internal structure of MC12079 plays a crucial role in determining its performance. The arrangement and connections of the components inside the IC determine its functionality and capabilities. Any flaws or defects in the internal structure can affect the overall performance of the IC and may lead to malfunctions or failures.

3. Are there any standards for the internal structure of MC12079?

Yes, there are industry standards that govern the internal structure of MC12079 and other ICs. These standards ensure that the ICs are designed and manufactured in a consistent and reliable manner. They also specify the quality and reliability requirements that the IC must meet to be used in various electronic devices.

4. Can the internal structure of MC12079 be modified or customized?

Yes, the internal structure of MC12079 can be modified or customized to suit specific applications or design requirements. This can be done during the design and manufacturing process of the IC. However, any modifications must comply with the industry standards to ensure the reliability and functionality of the IC.

5. How is the internal structure of MC12079 tested and evaluated?

The internal structure of MC12079 is tested and evaluated through various methods, including electrical testing and visual inspection. Electrical testing involves applying different voltages and currents to the IC and analyzing its response. Visual inspection involves examining the IC under a microscope to check for any defects or abnormalities in the internal structure. These tests help ensure that the IC meets the required standards and functions properly.

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