摘要:
A differential amplifier comprises a Darlington differential pair (T₁/T₃, T₂/T₄) and a cross-coupled transistor pair (T₅, T₆) to increase the transconductance of the Darlington differential pair (T₁/T₃, T₂/T₄). The negative input impedance of the differential amplifier as a result of the presence of the cross-coupled differential pair (T₅, T₆) is compensated for at high frequencies and the gain of the differential amplifier is reduced by a compensation circuit with a capacitor (30) between the control electrodes of the transistors of the cross-coupled differential pair (T₅, T₆) and with resistors (26, 28) in series with the control electrodes of the transistors of the cross-coupled differential pair (T₅, T₆).
摘要:
Current feedback is employed in differential and unbalanced input wideband feedback amplifiers to render bandwidth and transient response insensitive to closed loop gain over a wide range. In the differential amplifier, two NPN transistors (Qa, Qb) have their emitters connected by a resistor (Ra) and receive input signals (Va, Vb) at their bases. The collectors are connected to a current or voltage mirror, and gain means (A(s)) and a resistor (Rc) are connected between one of the collectors and the emitter of the transistor (Qa).
摘要:
Eine zwischen die Emitter einer Differenzverstärkerstufe geschaltete Kapazität (c) entkoppelt die beiden Transistoren (T1, T2) des Differenzverstärkers bis zu einer Grenzfrequenz. An den Anschlüssen der Kapazität (C) lassen sich Änderungen des Gleichtaktsignals und an den Lastwiderständen (R1, R21 der Hochpaßschaltung die verstärkten hochfrequenten Differenzsignale abgreifen und weiterverarbeiten. Verglichen mit herkömmlichen Schaltungen gleicher Funktion ist nur noch eine frequenzbestimmende kapazität (C) erforderlich, die zudem weniger belastet wird.
摘要:
A power amplifier includes a two-dimensional matrix of N×M active cells formed by stacking main terminals of multiple active cells in series. The stacks are coupled in parallel to form the two-dimensional matrix. The power amplifier includes a driver structure to coordinate the driving of the active cells so that the effective output power of the two-dimensional matrix is approximately N×M the output power of each of the active cells.
摘要:
A digital communication system for transmitting and receiving Digital Visual Interface (DVI) communication data signals and Display Data Channel (DDC) communication signals over a transmission line (32) comprises an open-loop equalizer circuit (70) and a DDC extender circuit (30). The open-loop equalizer circuit (70) is operable to receive DVI communication signals transmitted over the transmission line (32) and output equalized DVI communication data signals. The DDC extension circuit (30) is operable to inject a boost current at the receive end of the transmission line (32) during a positive transition in the DDC communication signal, and clamp the receive end of the transmission line (32) during a negative transition of the DDC communication signal.
摘要:
A method and apparatus are disclosed for polyphase filtering a first number of vertical lines of video data to generate a second number of vertical lines of video data and then polyphase filtering the second number of vertical lines of video data to re-create the first number of vertical lines of video data. The first number of vertical lines is larger than the second number of vertical lines. The polyphase filtering of the first number of vertical lines includes low-pass filtering and sample rate converting (down-converting) the first number of vertical lines to the second number of vertical lines. The polyphase filtering of the second number of vertical lines includes sample rate converting (up-sampling) the second number of vertical lines to the first number of vertical lines. Between the down-sampling and the up-sampling, video compression and de-compression may also be performed using, for example, standard compression and de-compression techniques.