Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Understanding CD4013B datasheet

Status
Not open for further replies.

neptune

Member
hello,
https://pdf1.alldatasheet.com/datasheet-pdf/view/26845/TI/CD4013B.html

I want to know few points in this datasheet.
♣ In 1st page> features > 6th point > Max. input current of 1uA at 18V
what is this current stands for ?
♣ why they use drain to source voltage terminology , when it is clearly supply voltage.
♣ Max. current that this IC can give to output is 15mA max (both Iol and Ioh), which can not light up an LED, then i suppose it will need a driver circuit to do this.
♣ Vol is 0.05V Max., it means this voltage will always be deducted from calculated output voltage. and how will one calculate output voltage. without using test circuits.
♣ Iin , if i use this IC how can one measure current which is to be given at Input.
without using test circuits.
♣ what is load capacitance ? according to fig5 if i use 5V supply , where should i look in graph for what will be my propogation delay, because i dont know whats my load capacitance.
 
hello,
https://pdf1.alldatasheet.com/datasheet-pdf/view/26845/TI/CD4013B.html

I want to know few points in this datasheet.
♣ In 1st page> features > 6th point > Max. input current of 1uA at 18V
what is this current stands for ?
Thats the maximum current drawn from the driving circuit.

♣ why they use drain to source voltage terminology , when it is clearly supply voltage.
Because CD4000 is CMOS technology
Vdd [ drain] Vss [source]


♣ Max. current that this IC can give to output is 15mA max (both Iol and Ioh), which can not light up an LED, then i suppose it will need a driver circuit to do this.
Relook at the tables for Source and Sinking current, its much lower than 15mA

♣ Vol is 0.05V Max., it means this voltage will always be deducted from calculated output voltage. and how will one calculate output voltage. without using test circuits.
This is the LOW state voltage of the output

♣ Iin , if i use this IC how can one measure current which is to be given at Input.
without using test circuits.
Its not required to measure the input current, its stated as above 1uA at 18V

♣ what is load capacitance ? according to fig5 if i use 5V supply , where should i look in graph for what will be my propogation delay, because i dont know whats my load capacitance.
Load capacitance is the 'capacitance' that a following circuit places on the output
At 5V if you assume the max load capacitance of 100pF, you will get ~170nSec propagation delay

Does that answer your questions.?
 
Last edited:
Relook at the tables for Source and Sinking current, its much lower than 15mA
yes in table it is given far lower values, but in graphs fig3 it is shown that typical low output is -30mA at -15V supply voltage.
Load capacitance is the 'capacitance' that a following circuit places on the output
what is following circuit
 
yes in table it is given far lower values, but in graphs fig3 it is shown that typical low output is -30mA at -15V supply voltage.

what is following circuit
Typical values are just that. You can't use them for worst-case design (i.e. to insure that the device with the worst-case manufacturing tolerance will operate properly).

The "following circuit" is whatever circuitry the IC output is driving. Stray capacitance is generated from this circuitry including wire and PCB trace capacitances. If you can't measure it then you have to estimate it.
 
ok thankyou
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top