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公开(公告)号：JPH07231227A
公开(公告)日：1995-08-29
申请号：JP4200794
申请日：1994-02-16
申请人： NEC CORP
发明人： TOMIYA FUMIO
摘要： PURPOSE:To suppress an output offset voltage to be small by connecting an operational amplifier of a pre-stage with a high gain and a low offset voltage and a DC amplifier at a post-stage for a broad band whose offset voltage cannot be decreased in cascade so as to apply negative feedback to the pre-stage circuit. CONSTITUTION:An input signal e1 of a broad band including a DC component such as PCM signal is impressed to an inverted input of an operational amplifier 1 whose offset voltage is very small while being divided by a voltage divider R3, R4, and also impressed to a noninverted input of a DC amplifier 2 whose offset voltage is high. An output eo of the DC amplifier 2 is fed back to the inverted input of the operational amplifier 1 via negative feedback resistors R1, R2 and the output eo of the DC amplifier 2 is led out as the circuit output signal. A voltage dividing ratio alpha by voltage divider resistors R3, R4 is expressed as alpha=R3/(R3+R4) and a feedback ratio beta by feedback resistors R1, R2 is expressed as beta=R2/(R1+R2). The offset voltage is very small for a broad band in the amplifier circuit of the configuration as above.
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公开(公告)号：JPH0794955A
公开(公告)日：1995-04-07
申请号：JP7039594
申请日：1994-04-08
申请人： RUKUROI SA
摘要： PURPOSE: To provide a high-speed precision synthesis amplifier for making a synthesis gain independent of a frequency, especially the low frequency action of a high-speed amplifier. CONSTITUTION: This high-speed synthesis amplifier 1 is provided with a compensation network 7 for correcting the thermal distortion at a low frequency of the high-speed amplifier F2. The compensation network is provided with a precision amplifier P3, the addition node 6 of the precision amplifier P3 is connected to an input side X8 by an input transmission network and positively connected to an output side Y9 by an output transmission network O5 and the input addition node 10 of the high-speed amplifier F adds the output of the precision amplifier P and negative input signals X.
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公开(公告)号：JPH06350362A
公开(公告)日：1994-12-22
申请号：JP13973993
申请日：1993-06-11
申请人： NEC CORP
发明人： TAKANO ISAMU
摘要： PURPOSE:To easily realize an amplifier with a desired band width for an ultra high frequency region by providing a distributed amplifier with a sufficiently broad band comprising a microwave integrated circuit and a BPF comprising a microstrip line connecting in series to the distributed amplifier and having a desired center frequency and a desired frequency band width in the high frequency amplifier. CONSTITUTION:The high frequency amplifier is provided with BPFs 1, 3 of reflection constant resistor bridged T type arranged on an input side and an output side and a distribute amplifier 2 comprising a microwave integrated circuit, The distribulted amplifier 2 is capable of ultra wide band amplification over several octaves, in which a gain flat characteristic in the band is excellent and a reflection loss of input, output signals is small. Each of the BPFs 1, 3 is provided with resistance elements R11, R12 whose one-side terminals are connected respectively to input output terminals and whose other terminals are connected in common and whose resistance is r0, a line L11 comprising a microstrip line and whose length of line is l, whose one end is open and whose 1st conductor of the other end connects to the input side and whose 2nd conductor is connected to the output side, and a line L12 comprising a microstrip line and whose length of line is l, whose one end is shorted and whose 1st conductor of the other end connects to the common connection point of the resistance elements R11, R12 whose 2nd conductor is connected to the input side and the output side.
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公开(公告)号：JPH06103805B2
公开(公告)日：1994-12-14
申请号：JP16851487
申请日：1987-07-06
摘要： To permit cooling of transistor push-pull bridge-type audio end stages in car radios, where heat dissipation and cooling of components is difficult to achieve, without entire interruption of signals being amplified, the temperature of a heat sink (HS) is being sensed by a temperature sensor (14), and, if a predetermined level is exceeded as determined, for example, by a threshold circuit (15), one of the bridge arms formed by a transistor (10) is controlled to become saturated, thereby grounding-out the applied signal, so that a loudspeaker (6) will operate at only half voltage and hence 1/4 power, to thereby permit cooling of components, while providing some reproduction of introduced audio signals from an audio input terminal (11).
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公开(公告)号：JPH06224653A
公开(公告)日：1994-08-12
申请号：JP893693
申请日：1993-01-22
发明人： KUMAMOTO TOSHIO , MIKI TAKAHIRO , KONO HIROYUKI
摘要： PURPOSE:To increase a mutual conductance without increasing an input capacity by applying a voltage changing according to a change in a voltage applied to a gate terminal to a base terminal of a MOS transistor(TR). CONSTITUTION:An NMOS TR 1 has a drain terminal 1D, a gate terminal 1G, a source terminal 1S and a base terminal 1B, and a voltage application circuit 2a is connected between the gate terminal 1G and the base terminal 1B. Then a voltage changing according to a voltage applied to the gate terminal 1G is applied to the base terminal 1B. That is, a source-base voltage VSB changes according to a change in the gate source voltage VGS of the NMOS TR 1, the mutual conductance gm is increased when a gate-source voltage VGS, that is, a voltage applied to the gate terminal 1G is increased depending on the characteristic of the NMOS TR 1, and the mutual conductance gm is decreased when the voltage applied to the gate terminal 1G decreased on the other hand.
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公开(公告)号：JPH06188642A
公开(公告)日：1994-07-08
申请号：JP33988392
申请日：1992-12-21
申请人： NIPPON ELECTRIC ENG
发明人： SUZUKI FUMIO , ISHIHARA TADASHI
摘要： PURPOSE:To attain amplification up to a high frequency band stably by inserting a transistor(TR) in cascode connection between an input terminal and a negative feedback amplifier comprising an inverting amplifier and a feedback resistor and driving the TRs at a constant current. CONSTITUTION:An npn TR 6 is in cascode connection between an input terminal 1 and a negative feedback amplifier comprising an inverting amplifier 3 and a feedback resistor 4 and the npn TR 6 is driven at a constant current from a constant current source 5. Thus, when the base current of the npn TR 6 is sufficiently small, a same current as a signal current inputted to the input terminal 1 is supplied from the negative feedback amplifier. Thus, the input impedance is smaller by increasing a current of the constant current source 5 and a high band coverage is obtained by adding a parasitic capacitance to the input terminal 1. Furthermore, a voltage gain of the inverting amplifier 3 is adjusted to cope with deterioration in the band due to the collector parasitic capacitance of the npn TR 6 and the wiring parasitic capacitance.
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公开(公告)号：JPH06140851A
公开(公告)日：1994-05-20
申请号：JP28970992
申请日：1992-10-28
申请人： NEC CORP
发明人： NAKADA TAKAAKI
摘要： PURPOSE:To provide the high frequency amplifying semiconductor integrated circuit which can match the impedance with an external transmission line over wide bands. CONSTITUTION:An double step feedback wide band amplifier is constituted of bipolar transistors Q1 and Q2 and feedback resistors RE1, RE2 and RF. Then, an internal matching circuit 6 constituted of a resistor RI and inductance LI is provided between an output terminal TO and a power supply terminal TC as shown by a dotted line.
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公开(公告)号：JPH06125224A
公开(公告)日：1994-05-06
申请号：JP29795892
申请日：1992-10-09
发明人： KIMURA SHUNJI , IMAI YUUKI , NAKAMURA MAKOTO
摘要： PURPOSE:To compensate the deterioration of an output impedance and to improve the gain frequency characteristic by connecting a series circuit of a resistor and a capacitor to an output terminating circuit in parallel to a terminating resistor. CONSTITUTION:A drain side terminating circuit 13 is constructed by connecting a series circuit consisting of a capacitor 14 and a resistor 15 in parallel to a terminating resistor 8. The impedance of the circuit 13 has the frequency characteristic to show a low level at the high frequency side and a high level at the low frequency side respectively. Thus the circuit 13 compensates the frequency characteristic of the characteristic impedance of a distribution constant circuit at the drain side. That is, the resistance value of the resistor 8 and a bias circuit 10 are properly set at different levels so that the impedance is increased at the low frequency side. Thus the gain is increased at the low frequency side. At the same time, the resistance value of the resistor 15 is properly set so that the increase of the gain is suppressed at the high frequency side.
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