Driver circuit for subscriber terminals
AssigneeInfineon Technologies AG
InventorThomas Ferianz
Life of this patent
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Abstract
Driver circuit for at least one subscriber terminal, comprising a first driver (14) for amplifying the power of a direct-voltage signal applied for supplying power to the subscriber terminal, the first driver (14) being supplied by a first supply voltage (V1), and comprising a second driver (37; 37a, 37b), following the first driver, for modulating high-frequency signal currents onto the power-amplified direct-voltage signal.
Claims26
Driver circuit for at least one subscriber terminal, comprising:
- a first driver (14) for amplifying the power of a direct current for supplying power to the subscriber terminal, for amplifying the power of voice signal currents and of a ringing tone current, the first driver (14) being supplied by a first supply voltage (V1), and comprising
- a second driver (37;
- 37a, 37b) following the first driver (14) for modulating high-frequency data signal currents onto the signal currents power-amplified by the first driver (14).
Driver circuit according to one of the preceding claims, characterized in that the low-pass filter (30) is a first-order low-pass filter.
Driver circuit according to one of the preceding claims, characterized in that the first-order low-pass filter is an RC low-pass filter with a resistor (31;
- 31a, 31b) and a capacitor (32).
Driver circuit according to one of the preceding claims, characterized in that the cut-off frequency fG of the low-pass filter (30) can be adjusted.
Driver circuit according to one of the preceding claims, characterized in that the cut-off frequency fG of the low-pass filter (30) is between the upper cut-off frequency of the low-frequency signal currents and the lower cut-off frequency of the high-frequency signal currents.
Driver circuit according to one of the preceding claims, characterized in that a first voltage source (22) is provided for generating the first voltage (V1) which has a fixed reference potential.
Driver circuit according to one of the preceding claims, characterized in that a second voltage source (45;
- 45a, 45b) for generating the second supply voltage (V2;
- V2a, V2b) is provided which is connected free of reference potential to an output (34;
- 34a, 34b) of the low-pass filter (30).
Driver circuit according to one of the preceding claims, characterized in that the second supply voltage (V2;
- V2a, V2b) for the second driver (37;
- 37a, 37b), delivered by the second voltage source (45;
- 45a, 45b), is much lower than the first supply voltage (V1) for the first driver (14), delivered by the first voltage source (22).
Driver circuit according to one of the preceding claims, characterized in that the first driver (14) is an operational amplifier.
Driver circuit according to one of the preceding claims, characterized in that the second driver (37) is an operational amplifier.
Driver circuit according to one of the preceding claims, characterized in that a low-frequency signal source (4) can be connected to a signal input (15) of the first driver (14).
Driver circuit according to one of the preceding claims, characterized in that an output (40) of a summing circuit (8) is connected to a signal input (38) of the second driver (37).
Driver circuit according to one of the preceding claims, characterized in that the low-frequency signal source (4) can be connected to a first input (7) of the summing circuit (8).
Driver circuit according to one of the preceding claims, characterized in that the high-frequency signal source (5) can be connected to a second input (10) of the summing circuit (8).
Driver circuit according to one of the preceding claims, characterized in that a third supply voltage source (13) is connected to a third input (11) of the summing circuit (8) to increase the signal level at the signal input (38) of the second driver (37).
Driver circuit according to one of the preceding claims, characterized in that the third supply voltage source (13) delivers a supply voltage (V3) which has half the amplitude of the second supply voltage (V2)
Driver circuit according to one of the preceding claims, characterized in that the subscriber terminal can be connected to a signal output (49) of the second driver (37).
Driver circuit according to one of the preceding claims, characterized in that the data signal currents are xDSL data signal currents.
Driver circuit according to one of the preceding claims, characterized in that the driver circuit (1) is of differential construction.
Driver circuit according to claim 34, characterized in that the second driver (37) consists of two differentially interconnected operational amplifiers (37a, 37b) which are in each case supplied by a supply voltage (V2a, V2b) free of reference potential.
Dependencies are inferred from the claim text.