Data sheet acquired from Harris Semiconductor. SCHSC − Revised October HCDB consists of an oscillator section and December CDBMS. CMOS 14 Stage Ripple-Carry Binary Counter/ Divider and Oscillator. DATASHEET. Pinout. Functional Diagram. HEF Datasheet, HEF PDF, HEF Data sheet, HEF manual, HEF pdf, HEF, datenblatt, Electronics HEF, alldatasheet, free.

Author: Nikolabar Jukora
Country: Colombia
Language: English (Spanish)
Genre: Life
Published (Last): 4 November 2015
Pages: 93
PDF File Size: 10.35 Mb
ePub File Size: 16.22 Mb
ISBN: 623-7-27743-310-3
Downloads: 80879
Price: Free* [*Free Regsitration Required]
Uploader: Dilmaran

IC2 forms hef datasheet time base oscillator and first pre-scaler stage. By using our site, you acknowledge that you have eatasheet and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Moreover, I think that if I have a 11MHz signal output on the pin 9, it should means that the oscillator is working Basically, the intrinsic capacitance of the breadboard may already be equivalent to datahseet needed crystal load caps.

You’re going to have to start looking for the improbable: I’m building on a breadboard a 16Mhz oscillator part of another circuit with the HEFB using an external xtal. In SET mode the SET signal is high, and the seconds darasheet minutes carry can never occur because the seconds counter is held in reset.

This signal is fed to the seconds counter, as described below.


Axeman 3, 14 When the hours counter is reset, so is the flip-flop, making its Q output high. It also produces several other division ratios. In SET mode the SET signal is high, and the seconds to minutes carry can never occur because the seconds counter is held in reset. I suggest fitting a 10nF to nF ceramic capacitor next to the hole of pin 16 and pin 8 respectively. I’ve added it again. It must be a problem so silly that’s too evident for me to see!!


BrianCarlton Sorry, I already added the link to the datasheet in the first post, but it got lost somewhere.

This reset pulse is very short, because once it is high, the counters are reset and the reset pulse is gone again. The Hardware Part 1 You can download the circuit diagram here.

But this time the maximum count value is limited to Everything is built on pad board using Road Runner datahseet to connect all the components together. This reset pulse is very short, because once it is high, the counters are reset and the reset hef datasheet is gone again. Its signal level is constantly low, with only a very short rising pulse when the counter reaches 60 minutes.

oscillator – HEFB counter doesn’t count – Electrical Engineering Stack Exchange

The precision of the resistor value has no effect on the precision of the time base B. As a matter of fact, there’s no more on sheet number one to be explained. Problem is that I have fixed values on the output pins! As such, your effective crystal loading capacitance may be far exceeding the point where the circuit will successfully begin or sustain oscillation.

Another link from an Illinois ECE college course states:. My way of keeping this site alive. I have covered the time base and the counters here.

We’ll have to tell the clock what time it is when it has lost all its power anyway. There’s one output we might use though.

Like I said in a comment before, you may need to start looking for the improbable, or things that you take for granted because they usually don’t fail: We haven’t talked about the carry from the seconds counter to the minutes counter yet. That means a huge parasitic series inductance for 16MHz.


The relative high contact resistance can already daatsheet a problem for DC and very low frequency circuits. The CLK input to the flip-flop is low, because the hours counter has just been reset to 0.

We are only interested in two others, the Hz and the 64Hz outputs, which are used in the display section of the clock. If you can, I would strongly suggest lifting datazheet two crystal pins bend the leads on the DIP package up, so they poke out of the device horizontallyand soldering the crystal and caps directly to them.

SB-Projects – Projects – CMOS Clock – Hardware

The other sheet covers the display circuit and the power supply. TP1 is a test point at hef datasheet you hef datasheet measure the buffered hef datasheet While the clock is in run mode SET is high, opening the gate for the carry pulse.

But I think that this could be a problem caused by the breadboard as apalopohapa said. Dagasheet, the parasitic capacitance that the breadboard adds will affect the oscillator circuit, so you may have to adjust for this. One significant factor that most people neglect is the series parasitic inductance on the supply line.

When the clock het4060 switched to SET mode though, the SET line goes low, which keeps the reset dahasheet to the seconds counter constantly high, preventing the seconds counter to count.

Sign up using Facebook.