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.

A Question about an Op Amp

Status
Not open for further replies.

tamerakshar

Full Member level 1
Joined
Jan 29, 2006
Messages
97
Helped
10
Reputation
20
Reaction score
1
Trophy points
1,288
Activity points
2,268

well, since its connected to the transistor gates ; i bet its a current limiting resistors.
 

beckchm

Banned
Joined
Nov 13, 2005
Messages
191
Helped
3
Reputation
6
Reaction score
1
Trophy points
1,298
Activity points
0
esd

but let gate do not float
 

vlsiattitude

Junior Member level 3
Joined
Mar 5, 2005
Messages
31
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
1,523
its to limit the esd current that passes through reversed biased diodes.
 

Miguel Gaspar

Advanced Member level 1
Joined
Mar 6, 2006
Messages
479
Helped
70
Reputation
140
Reaction score
34
Trophy points
1,308
Location
Culiacán, Sinaloa, Mexico
Activity points
4,971
Well, no matter how well designed the transistors are, they are always different
and the resistors R1 and R2 are used to activate the transistors. If you put the same source to both inputs only one transistor will activate. But with the resistances both will be activated.
 

omsi

Member level 5
Joined
Jan 24, 2006
Messages
93
Helped
7
Reputation
14
Reaction score
4
Trophy points
1,288
Location
London
Activity points
2,105
the resistors at the inputs of transistors are kept for two functions.
1. to avoid floating gate when the inputs are left open.
2.to protect gate from any spikes in transient level.
 

jiaming_lee

Junior Member level 2
Joined
Jan 24, 2006
Messages
20
Helped
2
Reputation
4
Reaction score
0
Trophy points
1,281
Activity points
1,482
if the opa used in feedback mode, with proper set resistance of R1 and R2, which are compared to output resistor, R1 and R2 can help balance the input and output resistance
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top