Can someone please tell me how I would implement ripple blanking with a CD4511?
I want all digits except the least significant digit to be blank if the value is zero. I tried
feeding the A, B, C and D inputs of the CD4511 into a CD4072 and the out of that into
pin 4 of the CD4511, rather than having pin 4 permanently set high. This did not work
as it looked like the timing was not right.

thanks

 

A simple setup could be like this...

And a feed via a diode from the previous BL signal will allow the 0 to be displayed if the previous one is non zero.
If the inputs change between display times, an additional latch feeding the signal to the BL pin would be needed.

A circuit of your setup would help.

 

It would be difficult to implement ripple blanking with CD4511.
Use SN7447, SN7448 or derivatives of these.

 

It would be difficult to implement ripple blanking with CD4511.
Use SN7447, SN7448 or derivatives of these.

Why would make CD4511 without rbi input and output?
Can TTL be used when all other chips are 4000 cmos?

 

SN74LS47 drives common anode LED 7-segment displays.
SN74LS48 drives common cathode LED 7-segment displays.

While it is not recommended to mix TTL logic with CMOS logic, this should still work as display drivers.
74LSxx series works at 5V supplies. Test to see if it will operate with CMOS 0-5V signals.

 

SN74LS47 drives common anode LED 7-segment displays.
SN74LS48 drives common cathode LED 7-segment displays.

While it is not recommended to mix TTL logic with CMOS logic, this should still work as display drivers.
74LSxx series works at 5V supplies. Test to see if it will operate with CMOS 0-5V signals.

If I use 74LS series is there a chip that is comparable to the CD4060 oscillator / counter?

 

A simple setup could be like this...
View attachment 334756
And a feed via a diode from the previous BL signal will allow the 0 to be displayed if the previous one is non zero.
If the inputs change between display times, an additional latch feeding the signal to the BL pin would be needed.

A circuit of your setup would help.

 

If I use 74LS series is there a chip that is comparable to the CD4060 oscillator / counter?

Continue to use CMOS logic for the main part of the circuit. I will test 74LS47/8 for CMOS compatibility for you.

 

Continue to use CMOS logic for the main part of the circuit. I will test 74LS47/8 for CMOS compatibility for you.

Thank you sir.

 

I don't have on hand SN74LS47 or SN74LS48.
I have SN7447N.
Low level input current is
-0.4 mA for 74LS47
-1.6 mA for 7447

I don't have a CD4000 series counter.
I have SN74HC161. It drives SN7447 well. Datasheet states it can sink 4 mA.
CD4510B counter output can sink 1 mA at 5 V supply.

My conclusion, 7447 or 7448 will work. 74LS47 or 74LS48 would be preferred.
Note that 7447 is for common anode. 7448 is for common cathode.

 

I don't have on hand SN74LS47 or SN74LS48.
I have SN7447N.
Low level input current is
-0.4 mA for 74LS47
-1.6 mA for 7447

I don't have a CD4000 series counter.
I have SN74HC161. It drives SN7447 well. Datasheet states it can sink 4 mA.
CD4510B counter output can sink 1 mA at 5 V supply.

My conclusion, 7447 or 7448 will work. 74LS47 or 74LS48 would be preferred.
Note that 7447 is for common anode. 7448 is for common cathode.

Thank you for all your work!

 

I tried it with a CD4518 BCD section and an ancient (1975) 7447A, and the counter was pulling the decoder inputs down to 0.2 volts, so more than good enough!

 

I tried it with a CD4518 BCD section and an ancient (1975) 7447A, and the counter was pulling the decoder inputs down to 0.2 volts, so more than good enough!

thanks sarahMCML