摘要:
La présente invention concerne un dispositif de conversion CONV, muni d'une tension d'entrée symétrique Vin en une tension de sortie asymétrique Vout, comprenant :
. un module transconductance TCM destiné à délivrer un courant itcm dont la valeur est liée à celle de la tension d'entrée Vin, et . un module résistif RM destiné à transformer le courant itcm en une tension Vout référencée par rapport à un potentiel prédéterminé.
Selon l'invention, le module transconductance TCM comporte une paire différentielle (Q1, Q2), recevant la tension d'entrée Vin, et des moyens de soustraction SUB destinés à recevoir les courants de collecteur issus de la paire différentielle (Q1, Q2), et à délivrer un courant itcm représentatif de la différence entre lesdits courants.
Applications : interface de circuits intégrés avec un circuit imprimé au sein d'appareils de radio-téléphonie.
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 cascaded amplifier is comprised of a number of amplifying stages connected in cascade such as the dual emitter-coupled amplifier shown. A first pair of transistors (14,20) provides limiting amplification and a second pair of transistors (16,18) with degeneration (22,24) provide linear amplification. Each pair of transistors is driven by a current source (28,26) which supplies a current (IT, IT2) proportional to absolute temperature (PTAT). The small signal amplification is then substantially independent of temperature and the value of the limited output is proportional to absolute temperature. This latter effect is countered by including a translinear variable current gain amplifier (54,56,58,60) in the last dual-gain stage of the cascaded amplifier to modify the output voltage in a manner inversely proportional to absolute temperature. A transfer function may thus be provided which is substantially independent of temperature.
摘要:
An optical modulator driver circuit (1) includes an amplifier (50, Q10, Q11, R10 - R13), and a current amount adjustment circuit (51) capable of adjusting a current amount of the amplifier (50) in accordance with a desired operation mode. The current amount adjustment circuit (51) includes at least two current sources (IS10) that are individually ON/OFF-controllable in accordance with a binary control signal representing the desired operation mode.
摘要:
Zur Verbesserung des Rauschens, der Linearität und der Gleichtaktunterdrückung bei einem Differenzverstärker, weist dieser zwei Transistoren (Tl, Tl'), zwei Differenzverstärkereingänge (E, E'), die auf die Steuereingänge der Transistoren (Tl, Tl') führen, und zwei Induktivitäten (L, L') auf. Die beiden Induktivitäten (L, L') sind magnetisch miteinander gekoppelt, und verbinden die beiden Transistoren (Tl, Tl') mit einem Bezugspotential (M). Die Differenzverstärkerausgänge (A, A') sind mit den Ausgangskreisen der Transistoren (Tl, T1') verbunden. Ferner können die beiden Induktivitäten über eine Koppelkondensator (C) miteinander verbunden sein.
摘要:
An optical modulator driver circuit (1) includes an amplifier (50, Q10, Q11, R10 - R13), and a current amount adjustment circuit (51) capable of adjusting a current amount of the amplifier (50) in accordance with a desired operation mode. The current amount adjustment circuit (51) includes at least two current sources (IS10) that are individually ON/OFF-controllable in accordance with a binary control signal representing the desired operation mode.
摘要:
Differential amplifier with signal-dependent quiescent current control, comprising: a first (T₁) and a second (T₂) transistor of the same conductivity type for conducting a first (I₁) and a second (I₂) current respectively, the two transistors comprising each a control electrode coupled to a first (6) and a second (8) input terminal respectively, for feeding an input signal, a first main electrode coupled to a common terminal (3), converting means (10A, 10B) for converting the first and the second current to a measuring current in response to the first and the second current, comparing means comprising a control output terminal (11) for presenting a signal (I S ) in response to the difference between the measuring current and the reference current (2I Q ) of a reference current source (14), a controllable quiescent current source (4) coupled to the common terminal (3) for presenting a quiescent current (I O ) at the common terminal and having, coupled to the control output terminal (11), a control input (5) for controlling the quiescent current (I₀), whilst the converting means comprise: a first/second current generator (10A/10B) for generating a first/second derived current (I A /I B ) which decreases if the first second current (I₁/I₂) increases and vice versa , combining means (11) for generating the measuring current by adding together the first (I A ) and second (I B ) derived currents. Due to the inverse characteristic of the first/second current generator, the measuring current will be increasingly more dominated by the smaller of the first and second currents in the event of an increasing input signal, so that the minimum value of the smaller current will be determined by the reference current. Generating the first and second derived currents and combining them to the measuring current is a continuous process and can therefore react fast to amplitude variations in the first and second currents.
摘要:
A cascaded amplifier is comprised of a number of amplifying stages connected in cascade such as the dual emitter-coupled amplifier shown. A first pair of transistors (14,20) provides limiting amplification and a second pair of transistors (16,18) with degeneration (22,24) provide linear amplification. Each pair of transistors is driven by a current source (28,26) which supplies a current (IT, IT2) proportional to absolute temperature (PTAT). The small signal amplification is then substantially independent of temperature and the value of the limited output is proportional to absolute temperature. This latter effect is countered by including a translinear variable current gain amplifier (54,56,58,60) in the last dual-gain stage of the cascaded amplifier to modify the output voltage in a manner inversely proportional to absolute temperature. A transfer function may thus be provided which is substantially independent of temperature.