How to change voltage level 9-24 volts to 0-3.3 volts

Status
Not open for further replies.
C

chethan2689

Newbie level 1
Joined
Dec 29, 2014
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
9
Hi,
I am new to hardware design, i am using internal ADC MCU this voltage range is 0 to 3.3 volts but input voltage is 9 to 24 volts, anyone can give me the solution how convert this voltage level.
conversion level:
input output
less than or equal 9 volts = 0 volts
- -
greater than or equal to 24 volts = 3.3 volts

waiting for your reply

Thanks and regards,
chethan kumar
 

chethan2689 said:
Hi,
I am new to hardware design, i am using internal ADC MCU this voltage range is 0 to 3.3 volts but input voltage is 9 to 24 volts, anyone can give me the solution how convert this voltage

Thanks and regards,
chethan kumar
Click to expand...

your transfer function is

Vout = ( Vin -9V ) * 3.3/15 = Vin * 3.3/15 - 9*3.3/15

This can be done a number of ways with a reference voltage (9V or 1.98V) with a differential input and resistor ratios using a rail to rail Op AMP with 3.3V. Often ADC's have a free Op Amp included for level shifting.

Pay attention to behavior for saturated inputs (<9,>24)and consider using Sch. diode clamps if necessary from OA inputs to both rails.
 
you can use the zero crossing circuit with reference voltage of 9v.for this circuit vcc=3.3v and vss=0v
 

Is this the circuit you are looking?

When input is 9V.


When input is 24V


Best Regards
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…