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公开(公告)号：FR2818828A1
公开(公告)日：2002-06-28
申请号：FR0016934
申请日：2000-12-22
Applicant: ST MICROELECTRONICS SA
Inventor： MOURET MICHEL
Abstract: The device comprises a differential transconductor circuit (BTC) for converting an input signal (RF , RF ) into a differential current, and a current-switching circuit (COM) controlled by a local oscillator signal (LO , LO ) and connected between the differential stage of the transconductance circuit and the device output (BS1,BS2). The differential stage comprises two transistors (Q1,Q2), which are bipolar transistors of p-n-p type or p-MOS transistors, polarized by a current source (IP) connected to a supply terminal (Vcc). The current-switching circuit comprises four transistors (Q3,Q4,Q5,Q6) polarized by two current sources (IP1,IP2) connected to the ground and delivering currents which are higher than the current delivered by the first current source (IP). The differential transconductor circuit (BTC) also comprises two impedances (RE1,RE2) connected between the first current source (IP) and the emitters of transistors (Q1,Q2) of the differential stage; the impedances are of the same nature as the load impedances (ZL1,ZL2) at the device output, in particular inductances. If all the impedances are inductive, the maximum admissible level of output signal is equal to 2Vcc less the maximum voltage drop on the load impedance (ZL1,Zl2) at the device output, in particular inductances. If all impedances are inductive, the maximum admissible level of output signal is equal to 2Vcc less the maximum voltage drop on the load impedance (ZL1 or ZL2). The maximum admissible level of input signal (RF) is equal to the supply voltage less the voltage drop on the current source (IP), the base-emitter voltage, and the voltage drop on the impedance (RE1 or RE2). The minimum admissible level of input signal is practically nul, or slightly negative. The cellular mobile telephone incorporates the device.
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公开(公告)号：FR2818466A1
公开(公告)日：2002-06-21
申请号：FR0016400
申请日：2000-12-15
Applicant: ST MICROELECTRONICS SA
Inventor： MOURET MICHEL , SABUT MARC , VAN ZANTEN FRANCOIS
Abstract: The invention concerns a variable-gain differential input and output amplifier comprising an attenuation network (AT1, AT2), receiving an input voltage (V1in-V2in) and supplying on several outputs (O1i, O2i) voltages each of which is equal to the attenuated input voltage; differential transconductance elements (G1i, G2i) each having a first input connected to an output (O1i, O2i) of the attenuation network, and producing first (l ) and second (l +) positive currents and first (1 ) and second (1 ) negative currents, a set of current sources (10) for controlling transconductance of each transconductance element based on an analog control signal (Vcom); and an output block (26) converting the first and second input currents into a differential output voltage (V1out-V2out) and supplying to the second input of each transconductance element a feedback voltage dependent on the output voltage.
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公开(公告)号：FR2817408A1
公开(公告)日：2002-05-31
申请号：FR0015522
申请日：2000-11-30
Applicant: ST MICROELECTRONICS SA
Inventor： MOURET MICHEL , SABUT MARC , VAN ZANTEN FRANCOIS
Abstract: The invention concerns a controllable set of current sources (6') comprising several output terminals (Si), a first transistor (T1i') associated with each first output terminal, the current (li) on each first output terminal depending on the current passing through the first transistor, and control means (8) designed, in response to a predetermined control voltage variation (VAB), to make each first transistor (T1i') gradually conductive then gradually non-conductive, wherein the first transistors are MOS transistors, and wherein each first output terminal (Si) is associated with a current mirror formed by MOS transistors (T2i, T3i), said current mirror supplying to the first output terminal a current dependent on the current passing through the first transistor.
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