Linear-gain amplifier arrangement
First Claim
1. A linear-gain amplifier arrangement which comprises:
- a current-amplifying cell comprising a first and a second current-mirror circuit of which each comprises at least an input transistor and an output transistor to form a first and a second differential pair, respectively, and means coupled to the current-amplifying cell for defining the gain of the amplifier arrangement, wherein the transistors are all of the field-effect type and are biased to operate in their saturation regions, the input transistors being connected to a voltage-to-current converter which is responsive to an applied input voltage so as to supply difference currents which are related to said input voltage by a square-law function.
1 Assignment
0 Petitions
Accused Products
Abstract
A linear-gain amplifier arrangement comprises a current amplifying cell consisting of field-effect transistors and comprising a first (M1, M3) and a second (M2, M4current-mirror circuit whose respective input transistors (M1; M2) and output transistors (M3; M4) constitute a first and a second differential pair. The input transistors (M1; M2) have their drain electrodes connected to voltage-current converter (V/I) made up of field-effect transistors. The V/I converter supplies difference currents (Iin1 ; Iin2) which are square-law functions of the input voltage (Uin) to be amplified. The difference between these input currents is a linear function of the input voltage. When the transistors are operated in their saturation regions the difference between the output currents (Iout1 ; Iout2) is also a linear function of the input voltage (Uin). By adding a direct voltage (Vc) to the gate-source voltage of the input and output transistors or by adding a direct current (Ic) to the respective input currents (Iin1 ; Iin2) the gain can be varied without a change in bandwidth. When the arrangement is constructed as an integrated semiconductor circuit its gain can be made immune to temperature variations and tolerances in the fabrication process.
9 Citations
23 Claims
-
1. A linear-gain amplifier arrangement which comprises:
- a current-amplifying cell comprising a first and a second current-mirror circuit of which each comprises at least an input transistor and an output transistor to form a first and a second differential pair, respectively, and means coupled to the current-amplifying cell for defining the gain of the amplifier arrangement, wherein the transistors are all of the field-effect type and are biased to operate in their saturation regions, the input transistors being connected to a voltage-to-current converter which is responsive to an applied input voltage so as to supply difference currents which are related to said input voltage by a square-law function.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
16. A linear-gain amplifier comprising:
-
a first and a second current mirror circuit each of which comprises a diode-connected input field effect transistor and an output field effect transistor, means connecting the input transistors to form a first differential pair and the output transistors to form a second differential pair wherein each of said transistors is biased to operate in its saturation region, a voltage-to-current converter including first and second outputs and having an input for receiving an input voltage to be amplified, said voltage-to-current converter being responsive to said input voltage to supply difference currents to its first and second outputs which are related to said input voltage as a square-law function, means connecting the input transistors to respective first and second outputs of the voltage-to-current converter, and means coupled to at least one said differential pair for defining the gain of the amplifier. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
-
Specification