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.

Register Log in

replacment components

Status
Not open for further replies.
R

radium98

Full Member level 2
Joined
Jul 19, 2009
Messages
124
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,296
Location
leb
Activity points
2,255
hi to all members here i want to ask about equivalent replacment of these components thanks in advance

2SC668 and 2sa733

and ic TLC271 can i use instead 741
 


Using a 741 or an OP07 instead of a TLC271 is not possible. The TLC271 is a single supply op-amp and it's in- and outputs can operate close to ground while the 741 and the OP07 can't.

---------- Post added at 14:31 ---------- Previous post was at 14:28 ----------

You can try to read this app-note from TI:

**broken link removed**
 

FvM said:
You can't know without seeing the circuit.
Click to expand...

I have good reasons to believe that the poster is looking at a schematic that uses batteries for it's power supply.
 

I have good reasons to believe that the poster is looking at a schematic that uses batteries for it's power supply.
Click to expand...
O.K., but battery powered circuits can be designed with general purpose OPs, if you want to.
 

FvM said:
O.K., but battery powered circuits can be designed with general purpose OPs, if you want to.
Click to expand...

You are right about that. But a TLC271 and a 741 can not be exchanged for the reason I've given above. Why would you use a low bias current (the TLC271 has a dedicated bias setting pin), single supply op-amp if you could have used a cheap 741 instead. I think I posted something about single supply op-amps some time ago. But i can't seem to find it here in my history. Perhaps it was in an other forum. I post it here if I can find it. It's a write up on how to select op-amps. (input biasing in single supply applications and how to recognize op-amp's with a common mode the range that includes ground or VCC, common mode input range, output voltage range, load current capability (source and sink, because some can source but not sink very well.), bandwidth, supply current, and some tricks you can do with inverting amplifiers in a single supply application...)
 

I have good reasons to believe that the poster is looking at a schematic that uses batteries for it's power supply.in fact no i have to make an fm transmitter with 4 watts output and i cant find these 2sa733 and 2sc668 and tlc271 this is the schematic for that if it will help .

 

-A 741 or OP07 will not work in your circuit. You can use a LM358 instead. It's inputs and output can work close to ground.
-For Q1, you can use almost any PNP transistor. A BC557 or something alike will do fine.
-The 2SC668 seems to be an RF transistor. Not sure, but an MSPH10 might work.
https://www.onsemi.com/pub_link/Collateral/MPSH10-D.PDF
 

inventor(y) thanks for u i mentioned by mistake the transistor

2sc688 is infact 2SC668 (2sc668) thanks
 

inventor(y) said:
Using a 741 or an OP07 instead of a TLC271 is not possible. The TLC271 is a single supply op-amp and it's in- and outputs can operate close to ground while the 741 and the OP07 can't.

---------- Post added at 14:31 ---------- Previous post was at 14:28 ----------

You can try to read this app-note from TI:

**broken link removed**
Click to expand...

hi INVENTOR(Y)...
Thanks for your post... But...
You can use op07 or 741 in single supply. i have used it in my circuits & its working properly... you can operate in - out close to ground in op07 & 741...
Plz Just try it yourself....

---------- Post added at 14:55 ---------- Previous post was at 14:47 ----------
radium98 said:
I have good reasons to believe that the poster is looking at a schematic that uses batteries for it's power supply.in fact no i have to make an fm transmitter with 4 watts output and i cant find these 2sa733 and 2sc668 and tlc271 this is the schematic for that if it will help .

Click to expand...



You can use 2n3055 instead of 2sa733 in your circuit...

---------- Post added at 14:58 ---------- Previous post was at 14:55 ----------
inventor(y) said:
-A 741 or OP07 will not work in your circuit. You can use a LM358 instead. It's inputs and output can work close to ground.
-For Q1, you can use almost any PNP transistor. A BC557 or something alike will do fine.
-The 2SC668 seems to be an RF transistor. Not sure, but an MSPH10 might work.
https://www.onsemi.com/pub_link/Collateral/MPSH10-D.PDF
Click to expand...

Yes LM358 also right choice for this circuit.. But, that is not match pin to pin replacement of TLC271.. Which i seggest before is (op07 & 741) Pin to Pin combitable...
 

you can operate in - out close to ground in op07 & 741...
Plz Just try it yourself....
Click to expand...
You can't. OP07 common mode range typically starts 1 V above negative supply (which is GND in the present single supply circuit) and 741 2 V above ground. Negative output voltage has also a residual voltage of about 1 V. The VCO tuning range would be considerably reduced.

You can use 2n3055 instead of 2sa733 in your circuit...
Click to expand...
No. 2SA733 is a small signal PNP, 2N3055 is a NPN power transistor in huge TO3 case.
 

thanks for your post FvM...
Theoritically i acept this.... But i am using this circuit for square (4khz) wave generation using the same opamp... Its working good for me... its starts from 0 (Gnd)...



---------- Post added at 15:18 ---------- Previous post was at 15:14 ----------

& i am sure defenetly he (radium98) can use op07 or 741 in This (His) Circuit...
 

This isn't a theoretical question.

Your oscillator circuit will only work reliably with a dual supply, or an OP that includes ground in the common mode range.

Your circuit doesn't show how V- is connected. I guess, it's dual supply.
 

@ Senthilkumar_rjpm

you better start reading some basic things about op-amps. The TI app note I've posted I've posted is a good start. With dual supplies the 741 can swing to ground but not the app shown.
 

:cry::?: so please i am a bit confused
i can use lm358 instead of TLC271
For Q1, you can use almost any PNP transistor. A BC557 or something alike will do fine.
and any rf transistor c2053 equiva,ent to 2sc668
and bb105g instead of mv1204 varicap tuning diode
and prescaler mc3393 divider ratio here 15/16 instead of uPB571 programable divider here is 16 division factor

thanks
 

I can only comment on the TLC271: an LM358 can also be used here. The 741 and OP07 will not work in your circuit. I don't even have to try.
Q1: BC557

2SC668, i don't know if the 2SC2053 will work.

For the other parts you mention: i don't know without digging deep into the data sheets of the components you mention.
 

inventor(y) said:
@ Senthilkumar_rjpm

you better start reading some basic things about op-amps. The TI app note I've posted I've posted is a good start. With dual supplies the 741 can swing to ground but not the app shown.
Click to expand...

Mr.inventor(y).....
Thanks for your (valuable...) Advice.i am using This concept (which is u told wrong????) for the past 5 years.... & its working well many places with same ic....
& also i just share my own experiance here...(not try to show my deep theoritical knowledge????).. if The answere which i post is suit to questioner he may use otherwise.......???

AGAIN i am sure..... DEFENENTLY op07 or 741 will in his (radium98) circuit......
 

Senthilkumar_rjpm said:
Mr.inventor(y).....
Thanks for your (valuable...) Advice.i am using This concept (which is u told wrong????) for the past 5 years.... & its working well many places with same ic....
& also i just share my own experiance here...(not try to show my deep theoritical knowledge????).. if The answere which i post is suit to questioner he may use otherwise.......???

You still haven't told us what power supply you are using in your circuit. Here is a data sheet of the LM741. Page 4 shows a diagram of it's internals. Tell me, how will the input operate with it's input's close to ground? How about the biasing of the input stage? And how are you going to drive the output to ground with an PNP transistor at the output?

theoritical knowledge? Get some while you still can.
Click to expand...
 

Senthilkumar_rjpm said:
Mr.inventor(y).....
Thanks for your (valuable...) Advice.i am using This concept (which is u told wrong????) for the past 5 years.... & its working well many places with same ic....
& also i just share my own experiance here...(not try to show my deep theoritical knowledge????).. if The answere which i post is suit to questioner he may use otherwise.......???

AGAIN i am sure..... DEFENENTLY op07 or 741 will in his (radium98) circuit......
Click to expand...

i have been using op07 as an amplifier for the past 15+ years in all my analog small signal conditioning circuits and i can assure you neither 741 nor op07 will ever work on a single supply which is shown in the circuit. So i would strongly suggest the poster to take inventors recommendation to try out a lm358 instead as it can operate reliably at near ground conditions.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top