# cmos presettable divide by n counter hcf4018b

#### imraneesa

Joined Dec 18, 2014
227
Dear All,

I have the above mentioned chip in a car amplifier. I don't know about this chip. What is use of this chip and how can I check if this is functioning good. I have been repairing car amplifiers for long time but this is the first time I came across this chip. Please help me.

#### WBahn

Joined Mar 31, 2012
28,168
Have you looked up the data sheet?

To determine if it is working properly (without removing it), the best is probably to probe the inputs and outputs and see if the outputs are behaving in accordance with the data sheet for the given inputs.

There is no way for us to guess what this chip is being used for in a particular circuit -- that was determined by the designer.

#### imraneesa

Joined Dec 18, 2014
227
Have you looked up the data sheet?

To determine if it is working properly (without removing it), the best is probably to probe the inputs and outputs and see if the outputs are behaving in accordance with the data sheet for the given inputs.

There is no way for us to guess what this chip is being used for in a particular circuit -- that was determined by the designer.
Normally in general in what way is this chip being used for?

#### WBahn

Joined Mar 31, 2012
28,168
Normally in general in what way is this chip being used for?
First, read the data sheet -- at least the basic material in it. Then ask questions to clear up any remaining questions you have.

#### GopherT

Joined Nov 23, 2012
8,009
Normally in general in what way is this chip being used for?
I assume that you've seen the datasheet since you bothered to post the name of the chip along with the chip's model number. I also agree that the use of the chip in a standard amplifier is unusual.

This chip can be used to divide frequencies down to lower frequencies (less common), it can also be set up as a ring to pass a series of preset initial bits around a ring if 10 possible states. That way, you can use a debounced momentary switch, a 4018 chip and generate a bunch of possible output combinations. This lets you select more than just on/off as you toggle through some selections with a single momentary button.

Depending on the preset values of each stage (high or low) and how many of the outputs are connected, you could get 2^N possible selection options as a binary output. In the case of this specific. Chip, 2, 4, 8, 16 or 32 options with changing inputs (every possible combination) or, you could get 2, 4, 6, 8 or 10 possible combinations if you have a static preset hard-wired to the input pins. The preset values loop through the outputs with each press of the button (clock pin).

Note: this is a Johnson-type ring counter. See below.
https://en.m.wikipedia.org/wiki/Ring_counter

Each of this states from the 4018 could control a display option, as you cycle through with the selector button, bass, treble, ...

It could turn on various levels of filtering, or adjust gain, just lots of things as each combination of bits are walked through the ring of the 4018.

Good luck.

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#### hp1729

Joined Nov 23, 2015
2,304
Dear All,

I have the above mentioned chip in a car amplifier. I don't know about this chip. What is use of this chip and how can I check if this is functioning good. I have been repairing car amplifiers for long time but this is the first time I came across this chip. Please help me.
Troubleshooting digital circuits without a schematic ...
I haven't seen one of these on the market in years. The original were TTL. I have modified it for CMOS. It is a DIP clip that clips over the IC to be tested. A known good chip is put in a socket. Switches are set to connect inputs from the IC being tested to the reference chip. The circuit is put through normal operation. It compares the outputs of the chip being tested with the outputs of the reference chip. This design assumes a 16 pin chip with power on 8 and 16.

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