Broadband driver circuit
AssigneeInfineon Technologies AG
InventorRudiger Koban
Life of this patent
Estimating the term…
Abstract
Broadband driver circuit for driving voice and data signals, having a current dividing circuit (37), which divides a current generated by a current source (38), in a manner dependent on a voice and data signal present at a signal input (21), into two base currents (Ib1, Ib2) for driving a first driver transistor (39) and a second driver transistor (40), the two driver transistors (39, 40) being constructed identically.
Claims19
Broadband driver circuit for driving voice and data signals, having:
- a current dividing circuit (37), which divides a current generated by a current source (38), in a manner dependent on a voice and data signal present at a signal input (21), into two base currents (Ib1, Ib2) for driving a first driver transistor (39) and a second driver transistor (40), the two driver transistors (39, 40) being constructed identically, and the current dividing circuit (37) having an NPN bipolar transistor or an NMOS transistor (43), whose base connection or gate connection (47) is connected to an output (49) of the control amplifier (45), whose collector or drain connection (44) is connected to the cascode transistor (41) and whose emitter or source connection (51) is connected to the base connection (53) of the first driver transistor (39).
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the two driver transistors (39, 40) are NPN bipolar transistors.
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the quiescent current (Iq) of the current source (38) is adjustable.
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the current dividing circuit (37) has a cascode transistor (41) connected to the current source (38).
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the signal input (21) is connected to a control amplifier (50).
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the cascode transistor (41) has a base connection (54), at which a fixed voltage is present, and a second connection, which is connected to the current source (38), and also a third connection (86), which is connected to the base connection (77) of the second driver transistor (40).
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the base connection (53, 77) and the emitter connection (71, 81) of the two driver transistors (39, 40) are in each case connected via a resistor (72, 82).
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the two driver transistors (39, 40) are in each case connected to a current measuring transistor (67, 66).
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that provision is made of a quiescent current control circuit (62) for controlling the quiescent current (IQ) of the current source (38).
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the cascode transistor (41) is a PNP bipolar transistor.
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the two driver transistors (39, 40) are Darlington transistors.
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the broadband driver circuit drives voice and data signals in a frequency band range from 0 to 1.1 MHz.
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the emitter connection (71) of the first driver transistor (39) and the collector connection (74) of the second driver transistor (40) are connected to a signal output (26) of the broadband driver circuit (22).
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the two driver transistors (39, 40) can be operated with a supply voltage (VP, VN) of about 0 to 80 V.
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the signal input (21) of the broadband driver circuit (22) is connected to a further control amplifier (94).
Broadband driver circuit according to one of the preceding claims,
- characterized
- in that the signal output (26) is connected via a resistor (32;
- 33) to a terminal connection line (34;
- 35) for the connection of a terminal (36).
Dependencies are inferred from the claim text.