Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Low cost low frequency oscillator

Status
Not open for further replies.

Jester

Full Member level 6
Full Member level 6
Joined
Aug 18, 2012
Messages
377
Helped
7
Reputation
14
Reaction score
7
Trophy points
1,298
Location
.
Activity points
4,754
I have the need for a low frequency (say 1kHz) oscillator as follows:

- Really inexpensive
- Reliable start-up -40 +90 deg C
- 0-5V output @ <10uA
- Accuracy 20%
- Duty cycle 25 - 75%
- power source; +5Vdc

The tried and true 555 circuit is pretty cheap: $0.44@qty10, or $0.22@qty100 (Digi-Key pricing)

Does anyone have a cheaper or more elegant solution?
1kHz.png
 

How about a single-gate Schmitt-trigger oscillator?
Digikey has 74AHCT1G14SE-7DITR-ND at $0.0425/3000
 
  • Like
Reactions: Jester

    Jester

    Points: 2
    Helpful Answer Positive Rating
'HCT14G may be best price readily available.

But do you need to guarantee 20% accuracy with a 10% supply over wide temp with what tolerance cap?
 
  • Like
Reactions: Jester

    Jester

    Points: 2
    Helpful Answer Positive Rating
'HCT14G may be best price readily available.

But do you need to guarantee 20% accuracy with a 10% supply over wide temp with what tolerance cap?

Actually for this application, the frequency is not critical at all, I can live with 50% accuracy.

I like the proposed solution, not only is it less expensive, it uses a smaller package (SC-70 vs. SOIC8) and one less component.

Thank you.

1kHz-r1.png
 

The ordinary 555 with a 5V supply has an output that is a minimum of only 2.75V if it has no load. The 555 draws a fairly high current all the time.
 

Hi,

any comparator should do. and three resistors and a c. plus a c for vcc decoupling.

it is very stable in time and has good stability on VCC change. Temperature drift is more a problem of the used C.

I don´t know if this solution is cheaper than others.

Klaus
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top