-
公开(公告)号：JPH07176004A
公开(公告)日：1995-07-14
申请号：JP40507490
申请日：1990-12-21
Applicant: ST MICROELECTRONICS SRL
Inventor： MURARI BRUNO , ROSSI DOMENICO , SAVINO PIERANTONIO
Abstract: PURPOSE: To provide a preamplifier capable of being directly connected to a magnetic head and eliminating the need of the presence of especially a reference voltage source different from a power supply voltage or the capacitor having a high value. CONSTITUTION: Differential circuits T5 and T6 provided with an input stage provided with the differential circuit and a transistor output stage T2 are provided. A differential stage is provided with an intrinsic offset voltage and can be grounded and directly connected to the magnetic head L. Transistors T5 and T6 form the differential circuit provided with a different bias current so as to reduce input equivalent noise. The magnetic head L is connected to the base terminal of the transistor T5 and the base terminal of the transistor T6 is connected to the intermediate point of a pair of resistors R1 and R2 serially connected with each other between the output stage T2 and the line of a reference voltage. In the form, the differential stages T5 and T6 bias output by the offset voltage without the need of additional components for the purpose.
-
公开(公告)号：DE69032087T2
公开(公告)日：1998-10-08
申请号：DE69032087
申请日：1990-12-13
Applicant: ST MICROELECTRONICS SRL
Inventor： MURARI BRUNO , ROSSI DOMENICO , SAVINO PIERANTONIO
Abstract: A low-noise preamplifier stage, in particular for magnetic heads, which comprises a differential circuit (T5,T6) and a single-transistor output stage (T2). The differential stage has an intrinsic offset voltage, is ground-connectable and can be directly coupled to the magnetic head (L) , the two transistors forming the differential circuit (T5,T6) having different bias currents in order to reduce the input equivalent noise. The base terminal of the first transistor (T5) of the differential circuit defines an input (IN) of the stage which can be connected directly to a terminal of the magnetic head (L); the other terminal of the head can be connected directly to the ground. The base terminal of the other transistor (T6) of the differential circuit (T5,T6) is connected to the intermediate point of a pair of resistors (R1,R2) which are mutually connected in series between the single transistor of the output stage (T2) and a line at reference voltage. In this manner the differential stage (T5,T6) biases the output with its offset voltage without requiring additional components for this purpose.
-
公开(公告)号：DE69032087D1
公开(公告)日：1998-04-09
申请号：DE69032087
申请日：1990-12-13
Applicant: ST MICROELECTRONICS SRL
Inventor： MURARI BRUNO , ROSSI DOMENICO , SAVINO PIERANTONIO
Abstract: A low-noise preamplifier stage, in particular for magnetic heads, which comprises a differential circuit (T5,T6) and a single-transistor output stage (T2). The differential stage has an intrinsic offset voltage, is ground-connectable and can be directly coupled to the magnetic head (L) , the two transistors forming the differential circuit (T5,T6) having different bias currents in order to reduce the input equivalent noise. The base terminal of the first transistor (T5) of the differential circuit defines an input (IN) of the stage which can be connected directly to a terminal of the magnetic head (L); the other terminal of the head can be connected directly to the ground. The base terminal of the other transistor (T6) of the differential circuit (T5,T6) is connected to the intermediate point of a pair of resistors (R1,R2) which are mutually connected in series between the single transistor of the output stage (T2) and a line at reference voltage. In this manner the differential stage (T5,T6) biases the output with its offset voltage without requiring additional components for this purpose.
-
公开(公告)号：IT1236927B
公开(公告)日：1993-04-26
申请号：IT2281989
申请日：1989-12-22
Applicant: ST MICROELECTRONICS SRL
Inventor： MURARI BRUNO , ROSSI DOMENICO , SAVINO PIERANTONIO
Abstract: A low-noise preamplifier stage, in particular for magnetic heads, which comprises a differential circuit (T5,T6) and a single-transistor output stage (T2). The differential stage has an intrinsic offset voltage, is ground-connectable and can be directly coupled to the magnetic head (L) , the two transistors forming the differential circuit (T5,T6) having different bias currents in order to reduce the input equivalent noise. The base terminal of the first transistor (T5) of the differential circuit defines an input (IN) of the stage which can be connected directly to a terminal of the magnetic head (L); the other terminal of the head can be connected directly to the ground. The base terminal of the other transistor (T6) of the differential circuit (T5,T6) is connected to the intermediate point of a pair of resistors (R1,R2) which are mutually connected in series between the single transistor of the output stage (T2) and a line at reference voltage. In this manner the differential stage (T5,T6) biases the output with its offset voltage without requiring additional components for this purpose.
-
-
-
Search Results
4
records
(took 0.028 seconds)
