JP2006260209A - Voltage controlling voltage source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a voltage controlling voltage source which adjusts a variable range of output voltage in a desired range between 0 V to supply voltage by making input voltage variable. <P>SOLUTION: The voltage controlling voltage source provides a band gap current supply 100 which makes use of a band gap circuit, and a voltage dividing resistor circuit 120 for dividing the control voltage of a voltage input terminal 113 to supply the divided control voltage to a current output section of the band gap current source 100. An output current flowing in a first resistor of the band gap current source 100 is prepared as monotonous increase current of a positive temperature coefficient, an output current flowing in a second resistor is prepared as monotonous decrease current of a negative temperature coefficient, and the monotonous increase current and the monotonous decrease current are prepared to be larger than emitter output current of a first NPN bipolar transistor of the band gap current supply 100. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a voltage control voltage source, and more particularly to a voltage control voltage source that suppresses variations in constant voltage output composed of a semiconductor integrated circuit.

In semiconductor integrated circuits, the characteristics of each element may deviate from design values due to manufacturing variations, and as a result, the characteristics of the circuit may not be as intended. Conventionally, for example, in FIG. 1 of Japanese Patent Application Laid-Open No. 2004-5048 (refer to Patent Document 1), a first field effect transistor Tr having a source and a gate connected to a first reference potential terminal 121 has been dealt with. ₁ , one end is connected to the first reference potential terminal 121, the source is connected to each of the first and second resistors R ₁ , R ₂ , and the first and second resistors R ₁ , R ₂ , and the gate is The drain is connected to the second and fourth field effect transistors Tr ₂ , Tr ₄ , the third resistor R ₃ , and the second reference potential terminal 120 connected to the drain of the first field effect transistor Tr ₁ , that a third resistor R ₃ and the third field effect transistor Tr _3, the gate of which is connected between the second field effect transistor Tr ₂ is disclosed.

Japanese Patent Laying-Open No. 2004-5048 (FIG. 1)

  However, in the device described in Patent Document 1, the variation in the constant voltage source due to the variation in resistance is reduced by suppressing the variation in the current value of the constant current source, but the variation in the output voltage is reduced. There was also a problem that it was not applicable.

  The present invention has been made to solve the above-described problems. By changing the input voltage, the output voltage can be adjusted within a desired range between 0 V and the power supply voltage (Vcc). An object is to provide a control voltage source.

  According to a first aspect of the present invention, there is provided a voltage controlled voltage source for connecting a base of a first NPN bipolar transistor and an emitter of a fourth NPN bipolar transistor having substantially the same emitter area ratio and a collector of a second NPN bipolar transistor. Are connected in common, the base of the second NPN bipolar transistor and the emitter of the third NPN bipolar transistor are connected together, the collector of the first NPN bipolar transistor is connected in common, and one of the reference voltage supply terminals is connected to the third The resistor is connected to the collector and base of the third NPN bipolar transistor, and the base of the fourth NPN bipolar transistor and the base of the fifth NPN bipolar transistor are commonly connected, and the other of the reference voltage supply terminals is connected to the second NPN bipolar transistor. 4 NPN bipolar transistors And the collector of the fifth NPN bipolar transistor, the emitter of the second NPN bipolar transistor connected through the first resistor, and the emitter of the fifth NPN bipolar transistor connected to the second resistor. A bandgap current source having a current output unit connected in common to an emitter output of the first NPN bipolar transistor and a current output unit by dividing a control voltage from a voltage input terminal. A voltage dividing terminal for supplying current to the voltage output terminal, the output current flowing through the first resistor is a monotonically increasing current with a positive temperature coefficient, and the output current flowing through the second resistor is The monotonically decreasing current has a negative temperature coefficient, and the monotonically increasing current and the monotonically decreasing current are the emitter output current of the first NPN bipolar transistor. It is characterized in that it has larger.

  According to a second aspect of the present invention, there is provided a voltage controlled voltage source for connecting the gate of the first N-channel MOSFET transistor and the source of the fourth N-channel MOSFET transistor having substantially the same source area ratio and the second N-channel MOSFET transistor. Are connected in common, the gate of the second N-channel MOSFET transistor and the source of the third N-channel MOSFET transistor are connected together, and the drain of the first N-channel MOSFET transistor is connected in common, and the reference voltage supply terminal One is connected to the drain and gate of the third N-channel MOSFET transistor via a third resistor, the gate of the fourth N-channel MOSFET and the gate of the fifth N-channel MOSFET transistor are connected in common, and the reference The other of the pressure supply terminals is connected to the drain of the fourth N-channel MOSFET transistor and the drain of the fifth N-channel MOSFET transistor, and the source of the second N-channel MOSFET transistor is connected via the first resistor. And a source connected to the source of the fifth N-channel MOSFET transistor via the second resistor, and a source output of the first N-channel MOSFET transistor is connected in common and used as a current output section. And a resistance voltage dividing circuit that divides the control voltage from the voltage input terminal and supplies the divided voltage to the current output unit, wherein the current output unit is a voltage output terminal, and the output current flowing through the first resistor is a positive temperature. The output current flowing through the second resistor is a monotonically decreasing current with a negative temperature coefficient. Serial monotonically increasing current and the monotonically decreasing current is characterized in that it has greater than the source output current of the first N-channel MOSFET transistor.

  As described above, according to the first aspect of the present invention, since the band gap current source circuit is connected to the voltage output terminal of the resistance voltage dividing circuit, by varying the input voltage, the variable range of the output voltage is 0V to It is possible to adjust within a desired range between the power supply voltages (Vcc), and to obtain an output voltage with a variable width that can be finely adjusted within a desired range with respect to the variable width of the input voltage.

  According to the second aspect of the present invention, since the MOSFET is used, even if there is a process variation or a change in environmental temperature at the time of manufacturing the resistance value of the resistance element (resistance element) of the band gap current source or the resistance voltage dividing circuit. Since the variation ratio of the resistance value of each resistance element in the semiconductor integrated circuit is uniform, a voltage control voltage source with high adjustment accuracy can be obtained.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIG. FIG. 1 is a circuit configuration diagram of a voltage controlled voltage source according to the first embodiment. In FIG. 1, reference numeral 100 denotes a bandgap current source, reference numeral 111 denotes a reference voltage supply that drives the bandgap current source 100 and is supplied with a reference voltage. Terminal (Vcc), 112 is a common ground terminal (ground) of the circuit, 113 is a voltage input terminal (Vcnt) for supplying a desired control voltage, 114 is a voltage output terminal (Vout) which is also an output part of a band gap current source, Reference numeral 120 denotes a resistance voltage dividing circuit that divides the voltage from the voltage input terminal 113 and is connected to the output unit 114 of the band gap current source. Reference numeral 200 denotes a voltage control voltage source configured by a semiconductor integrated circuit in which the band gap current source 100 and the resistance voltage dividing circuit 120 are incorporated.

  Next, the operation will be described. As shown in FIG. 1, the voltage control voltage source 200 is a band using a bandgap circuit for the voltage output terminal 114 of the resistance voltage dividing circuit 120 composed of the fourth resistor (R4) and the fifth resistor (R5). The circuit configuration is such that the gap current source 100 is connected. First, the circuit of the band gap current source 100 will be described. In FIG. 1, the current I2 flowing through the first resistor (R1) is I2 = (1 / R1) from the relationship between the emitter area of the bipolar transistor Q2 (indicated by m) and the emitter area of the bipolar transistor Q3 (indicated by n). ) VTln (mxn), VT = kT / q> 0 and (1 / R1) ln (mxn)> 0 (k is Boltzmann's constant, q is charge of one electron, T is absolute temperature VT is thermal voltage constant ), The current I2 monotonously increases with respect to the absolute temperature (T) because I2∝T and the slope is positive. ... (1)

  Further, the current I3 flowing through the second resistor (R2) becomes V3-Vout = VBEQ1 + VBEQ4-VBEQ5 from I3 = (V3-Vout) / R2. Here, VBEQ1, VBEQ4, and VBEQ5 are the base-emitter voltages of the bipolar transistors Q1, Q4, and Q5, respectively, and V3 is the emitter voltage of the bipolar transistor Q5. In addition, it is known that the voltages VBEQ1, VBEQ4, and VBEQ5 are monotonously decreasing with a temperature coefficient of about −2 mV / ° C. with respect to T, and since R2> 0, the current I3 is Monotonically decreasing. ... (2)

  Therefore, the relationship between the current I1 flowing through the emitter of the bipolar transistor Q1 and the current I2 flowing through R1 and the current I3 flowing through R2 is I1 << I2 and I3 because of the monotonic increase / decrease relationship of (1) and (2). When the third resistor (R3) is adjusted, the total current I4 becomes a temperature-fixed current source independent of temperature.

  In the voltage controlled voltage source 200 in which the band gap current source 100 described above is connected to the resistance voltage dividing circuit 120 and a voltage is applied to the voltage input terminal 113, the following equation is established. Vout = I6xR4 = (I4 + I5) xR4≈ (I2 + I3 + I5) xR4. Here, I5 is a current from the voltage input terminal 113, I6 is a total current of the currents I4 and I5, and the fourth resistor (R4) and the fifth resistor (R5) are divided resistors of the resistor voltage dividing circuit. Note that I1 << I2 and I3.

  When the resistance values fluctuate by ± α% due to manufacturing variations of the resistors R1 to R5, assuming that the currents I2, I3, I5, and R4 after fluctuation are I2a, I3a, I5a, and R4a, respectively, I2a = 100 / (100 ± α) xI2, I3a = 100 / (100 ± α) xI3, I5a = 100 / (100 ± α) xI5, R4a = (100 ± α) / 100xR4. Therefore, Vout after the resistance value variation becomes Vout = {100 / (100 ± α) × (I2 + I3 + I5)} x {(100 ± α) / 100xR4} = (I2 + I3 + I5) × R4, and the voltage Vout before and after the resistance value variation is It becomes constant and does not fluctuate.

  Further, when the fourth resistor (R4) and the fifth resistor (R5) are set to desired values and the voltage of the voltage input terminal 113 is changed by the voltage control voltage source 200, I5 = (Vcnt−Vout) / From R5, Vout = (I4 + I5) R4, Vout = {R4 / (R4 + R5)} xVcnt + {R4xR5xI4 / (R4 + R5)}.・ (3)

  When Vcnt = Vcc is set, Vout = {R4 / (R4 + R5)} xVcnt + {R4xR5xI4 / (R4 + R5)} (4)

  Therefore, by adjusting the resistors R4 and R5 and the current I4, the values shown in the above (3) and (4) with respect to Vcnt = 0 to Vcc (unit: volt) at the voltage output terminal 114 are set as the lower limit upper limit. An output voltage can be obtained.

  Next, a case where the voltage control voltage source 200 is applied to a gain control voltage generation circuit (VGA) will be described with reference to FIG. In FIG. 2, 300 is a VGA, 311 is a control output terminal (VCONT1), and 312 is a control output terminal (VCONT2). In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  In FIG. 2, the base input voltage of the transistor Qc1 of the gain control voltage generation circuit 300 is supplied from the voltage output terminal 114 of the voltage control voltage source 200 using an external supply voltage input to the voltage input terminal 113 of the voltage control voltage source 200. Convert to

  The VGA 300 is a circuit that controls the VGA gain and generates a control voltage at the control output terminal 311 and the control output terminal 312, and controls the voltage at the control output terminal 311 and the control output terminal 312 by the base voltage of the transistor Qc 1. In this case, it is necessary to slightly change the voltage applied to the base of the transistor Qc1, and in such a case, there is an advantage that a stable control voltage with high accuracy can be obtained by using the voltage control voltage source 200.

  In the first embodiment, the circuit is described using a bipolar transistor, but a MOSFET transistor may be used instead of the bipolar transistor.

It is a circuit block diagram of the voltage control voltage source of Embodiment 1 of this invention. It is explanatory drawing at the time of applying the voltage control voltage source of Embodiment 1 of this invention to VGA.

Explanation of symbols

100 Band gap current source 111 Reference voltage supply terminal (Vcc)
112 Common ground terminal (ground)
113 Voltage input terminal (Vcnt)
114 Voltage output terminal (Vout)
120 Resistance Dividing Circuit 200 Voltage Control Voltage Source 300 Gain Control Voltage Generation Circuit (VGA)
311 Control output terminal (VCONT1)
312 Control output terminal (VCONT2)
Q1 first bipolar transistor Q2 second bipolar transistor Q3 third bipolar transistor Q4 fourth bipolar transistor Q5 fifth bipolar transistor R1 first resistor R2 second resistor R3 third resistor R4 second 4 resistor R5 5th resistor Qc1 VGA input transistor (bipolar transistor)

Claims (2)

The base of the second NPN bipolar transistor is connected to the base of the first NPN bipolar transistor and the emitter of the fourth NPN bipolar transistor having the same emitter area ratio and to the collector of the second NPN bipolar transistor. And the emitter of the third NPN bipolar transistor and the collector of the first NPN bipolar transistor are connected in common, and one of the reference voltage supply terminals is connected to the collector of the third NPN bipolar transistor via the third resistor. And the base of the fourth NPN bipolar transistor and the base of the fifth NPN bipolar transistor are connected in common, and the other of the reference voltage supply terminals is connected to the collector of the fourth NPN bipolar transistor and the fifth NPN bipolar transistor. Dora The output of the second NPN bipolar transistor connected via the first resistor and the output of the fifth NPN bipolar transistor connected via the second resistor. A bandgap current source having a current output unit by connecting the emitter outputs of the first NPN bipolar transistors in common and a resistance voltage dividing circuit for dividing the control voltage from the voltage input terminal and supplying the divided voltage to the current output unit; The current output unit is a voltage output terminal, the output current flowing through the first resistor is a monotonically increasing current with a positive temperature coefficient, and the output current flowing through the second resistor is a monotonically decreasing current with a negative temperature coefficient The monotonically increasing current and the monotonically decreasing current are larger than the emitter output current of the first NPN bipolar transistor. Voltage controlled voltage source configured by AND circuit. A gate of the first N-channel MOSFET transistor and a source of the fourth N-channel MOSFET transistor having substantially the same source area ratio are connected, and a drain of the second N-channel MOSFET transistor is connected in common. The gate of the transistor and the source of the third N-channel MOSFET transistor are connected, the drain of the first N-channel MOSFET transistor is connected in common, and one of the reference voltage supply terminals is connected to the third resistor via the third resistor. The gate of the fourth N-channel MOSFET and the gate of the fifth N-channel MOSFET transistor are connected in common to the drain and gate of the N-channel MOSFET transistor, and the other reference voltage supply terminal is connected to the fourth N-channel. Connect the drain of the OSFET transistor and the drain of the fifth N-channel MOSFET transistor, and connect the source of the second N-channel MOSFET transistor via the first resistor and the source of the fifth N-channel MOSFET transistor. The output connected via the second resistor is connected, and the source output of the first N-channel MOSFET transistor is connected in common to form a current output unit, and the control voltage from the voltage input terminal is divided. A resistance voltage dividing circuit that supplies the current output unit to the current output unit, wherein the current output unit is a voltage output terminal, the output current flowing through the first resistor is a monotonically increasing current having a positive temperature coefficient, and a second resistor The output current flowing through the device is a monotonically decreasing current with a negative temperature coefficient, and the monotonically increasing current and the monotonically decreasing current are Voltage controlled voltage source constituted by a semiconductor integrated circuit, characterized in that larger than the source output current of the first N-channel MOSFET transistor.

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