Operational amplifier hybrid system
First Claim
Patent Images
1. A hybrid circuit comprising:
- a first operational amplifier having an input and an output which has a very low impedance, the input of said first operational amplifier being connected to a first line, the output of said first operational amplifier being connected to an impedance bridge for sending outgoing signals to a two-wire transmission line, said first amplifier having a single ended output with an amplifier return path to a common point,a second operational amplifier having a differential input with high impedances, said second operational amplifier having a non-inverting input and an inverting input, the output of said second amplifier being connected to a second line, said inputs of said second amplifier being connected to said impedance bridge for receiving incoming signals from said two-wire transmission line wherein said inputs are balanced with respect to said bridge and to said common point, said second amplifier having a single ended output with an amplifier return path to said common point, andsaid impedance bridge having a first branch and a second branch, the top of said first branch and the top of said second branch each being connected to the output of said first amplifier, the bottom of said first branch and the bottom of said second branch each being connected to said common point, said first branch including a first impedance in series with the first wire of said two-wire transmission line, said bridge being capable of interfacing said two-wire line, the second wire of said two-wire line being connected to said common point, said second branch including a second impedance in series with a third impedance wherein said second and third impedances are equal, said non-inverting input being connected to said first wire, said inverting input being connected to the junction of said second and third impedances, said first impedance matching the impedance of said two-wire line, and said second and third impedances being selected to balance said bridge for producing equal first amplifier signals at said non-inverting and inverting inputs.
0 Assignments
0 Petitions
Accused Products
Abstract
This hybrid circuit utilizes two amplifiers such as operational amplifiers without transformers. A bridge arrangement is used in which there are four impedances, the line being one impedance. One amplifier is the second amplifier which is connected across two points of the bridge as a differential amplifier. The other amplifier is the first amplifier which is connected across the other two points of the bridge. One wire of the line acts as a common point for the bridge and the amplifier system. The bridge is a balanced configuration.
-
Citations
13 Claims
-
1. A hybrid circuit comprising:
-
a first operational amplifier having an input and an output which has a very low impedance, the input of said first operational amplifier being connected to a first line, the output of said first operational amplifier being connected to an impedance bridge for sending outgoing signals to a two-wire transmission line, said first amplifier having a single ended output with an amplifier return path to a common point, a second operational amplifier having a differential input with high impedances, said second operational amplifier having a non-inverting input and an inverting input, the output of said second amplifier being connected to a second line, said inputs of said second amplifier being connected to said impedance bridge for receiving incoming signals from said two-wire transmission line wherein said inputs are balanced with respect to said bridge and to said common point, said second amplifier having a single ended output with an amplifier return path to said common point, and said impedance bridge having a first branch and a second branch, the top of said first branch and the top of said second branch each being connected to the output of said first amplifier, the bottom of said first branch and the bottom of said second branch each being connected to said common point, said first branch including a first impedance in series with the first wire of said two-wire transmission line, said bridge being capable of interfacing said two-wire line, the second wire of said two-wire line being connected to said common point, said second branch including a second impedance in series with a third impedance wherein said second and third impedances are equal, said non-inverting input being connected to said first wire, said inverting input being connected to the junction of said second and third impedances, said first impedance matching the impedance of said two-wire line, and said second and third impedances being selected to balance said bridge for producing equal first amplifier signals at said non-inverting and inverting inputs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
Specification