KR20240029902A - Temperature sensor with reduced dispersion and improved precision - Google Patents

Abstract

The present invention averages circuit elements that may cause dispersion of electrical characteristics using a DEM and a chopper circuit, thereby eliminating mismatches between BJTs constituting a temperature sensor, mismatches between current sources, and offsets of amplifiers, thereby improving the electrical properties of the components. Provides a temperature sensor with reduced dispersion and improved precision that allows optimizing the precision of detection temperature regardless of the dispersion of characteristics. The temperature sensor with reduced dispersion and improved precision includes a temperature detection unit, a multiplexer, a signal conversion unit, and an output unit.

Description

Temperature sensor with reduced dispersion and improved precision}

The present invention relates to a temperature sensor, and in particular, circuit elements that may cause dispersion of electrical characteristics are averaged using a DEM and a chopper circuit to determine mismatch between BJTs constituting the temperature sensor, mismatch between current sources, and offset of the amplifier. It relates to a temperature sensor that optimizes the precision of detection temperature regardless of the distribution of electrical characteristics of components by eliminating the temperature sensor.

Temperature sensors are used in various fields such as monitoring ambient temperature, healthcare, high/low temperature protection of circuits, and temperature compensation of systems. Temperature sensors can generally be implemented using an on-chip BJT (On Chip Bipolar Junction Transistor), temperature coefficient of resistance, and signal delay or frequency variation depending on the charge/discharge characteristics of the resistor-capacitor.

Multiple elements that make up a temperature sensor can be produced through one process or multiple different processes, and process conditions may change during the production process or the electrical characteristics of the same product may change during the production process under the same process conditions. can do. As a result, errors may occur in which temperatures measured under the same conditions and objects are different.

For example, a BJT-based temperature sensor utilizes the temperature coefficient of the absolute value (V _BE ) of the voltage difference between the base and emitter of the BJT, which is influenced by low-frequency noise, current sources inside the circuit, and BJT circuit configuration. There are several error factors such as , and the gain of the variable gain amplifier.

The invention of US 8,665,130 B2, registered on March 4, 2014, is a BJT-based temperature sensor, but it has the disadvantage that errors still occur when measuring temperature because the current source ratio of the bias part varies depending on the distribution of the process.

The technical problem to be solved by the present invention is to average circuit elements that may cause dispersion of electrical characteristics using a DEM and chopper circuit, thereby eliminating mismatches between BJTs constituting a temperature sensor, mismatches between current sources, and offsets of amplifiers. The goal is to provide a temperature sensor with reduced dispersion and improved precision that can optimize the precision of the detected temperature regardless of the dispersion of the electrical characteristics of the components.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

The temperature sensor with reduced dispersion and improved precision according to the present invention for achieving the above technical problem includes a temperature detection unit, a multiplexer, a signal conversion unit, and an output unit.

The temperature detection unit averages the errors of the two BJTs by controlling the connection of the two BJTs and the amplifier whose base-emitter voltage level changes depending on the temperature using two switch control signals applied from the outside, and the two A first base-emitter voltage, a second base-emitter voltage, and a third DEM control signal corresponding to two different BJTs are output in response to the magnitude of the current that is adjusted in response to the change in temperature of the BJT. The multiplexer dynamically converts the first base-emitter voltage and the second base-emitter voltage in response to a multiplexer control signal and alternately switches them to a first output terminal and a second output terminal. The signal conversion unit dynamically switches the two voltages output from the first and second output terminals of the multiplexer in response to the two control signals, the third DEM control signal, and the chopping control signal and simultaneously converts them into digital signals. to generate a bit stream signal. The output unit adjusts the bandwidth of the bit stream signal and outputs it to the outside.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

As described above, the temperature sensor with reduced dispersion and improved precision according to the present invention averages circuit elements that may cause dispersion of electrical characteristics using a DEM and a chopper circuit, thereby eliminating mismatches between BJTs constituting the temperature sensor and current sources. It has the advantage of optimizing the accuracy of detection temperature regardless of the distribution of electrical characteristics of components by eliminating mismatch between components and offset of amplifiers.

The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below. will be.

1 is a block diagram of a temperature sensor with reduced dispersion and improved precision according to the present invention.
FIG. 2 is a specific example of the temperature sensor shown in FIG. 1 with reduced dispersion and improved precision.
Figure 3 is an example of a control signal used in a temperature sensor.
Figure 4 is an example of the connection of two chopping control signals (Fch & Fchb) and a chopper circuit.
Figure 5 is an example of a first current sourcing unit and an amplifying unit.
Figure 6 is an example of a biasing unit.
Figure 7 is an example of a second current sourcing unit and a second bias circuit.
FIG. 8 is an example of the multiplexer shown in FIG. 2.
Figure 9 is an example of a signal conversion unit.
Figure 10 is an example of the output bit stream and control signal of the signal conversion unit and the waveform applied to the signal conversion unit.

In order to fully understand the present invention, its operational advantages, and the objectives achieved by practicing the present invention, reference should be made to the accompanying drawings illustrating exemplary embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the present invention with reference to the accompanying drawings. The same reference numerals in each drawing indicate the same member.

1 is a block diagram of a temperature sensor with reduced dispersion and improved precision according to the present invention.

FIG. 2 is a specific example of the temperature sensor shown in FIG. 1 with reduced dispersion and improved precision.

For convenience of explanation, the control signal and chopper circuit used in the temperature sensor (hereinafter referred to as temperature sensor) with reduced dispersion and improved precision of the present invention will be described.

Figure 3 is an example of a control signal used in a temperature sensor.

Referring to Figure 3a, two control signals (p1, p2), two switch control signals (f1, f2), and two chopping control signals (Fch & Fchb) are two phase non-overlap signals. You can see that

In other words, assuming that the switch subject to control is activated when the two corresponding signals, that is, p1 and p2, f1 and f2, and Fch & Fchb, are logic high, p1, f1, or Fch are logic high. It can be seen that the section in the high state and the section in which f2 or Fchb is in the logical high state do not overlap.

Referring to Figure 3b, it can be seen that the switch control signal (f1) has a period that is an integer multiple of the chopping control signal (Fch), and the control signal (p1) is a signal that has a period that is an integer multiple of the switch control signal (f1). .

Figure 4 is an example of the connection of two chopping control signals (Fch & Fchb) and a chopper circuit.

Referring to FIG. 4, two chopping control signals (Fch & Fchb) with a two-phase non-overlap relationship alternately activate four switches (401 to 404), thereby generating two input signals (In 1 & In 2). You can see that it outputs alternately to two output terminals (Out 1 & Out 2).

The following description will be based on the signals and components shown in FIGS. 3 and 4.

Referring to FIG. 1, the temperature sensor 100 (hereinafter referred to as temperature sensor) with reduced dispersion and improved precision according to the present invention includes a temperature detection unit 110, a multiplexer 150, a signal conversion unit 160, and a multiplexer control signal generation unit ( 170), decimation filter 180, and digital backend 190.

Referring to FIG. 2, the temperature detection unit 110 performs the function of detecting the temperature of the place where the temperature sensor 100 is installed, and the PTAT current generation unit 120, the ΔV _BE generation unit 130, and the control unit 140 It is installed internally using two externally applied control signals (f1, f2), and includes at least two BJTs (Q1 & Q2) whose base-emitter voltage level changes depending on temperature, and an amplifier installed internally. By controlling the connection of (126), the error of at least two BJTs (Q1 & Q2) is averaged, and the magnitude of the current adjusted in response to the change in temperature of at least two BJTs (Q1 & Q2) is internally adjusted. Outputs the base-emitter current (V _{BE_R} , V _{BE_L} ) of at least two other installed BJTs (Q3 & Q4), respectively.

The PTAT current generation unit 120, which constitutes the temperature detection unit 110, includes two externally applied switch control signals (f1, f2), a first current steering control signal (C_str1) generated by the control unit 140, and a first current steering control signal (C_str1) generated by the control unit 140. It operates in response to the DEM control signal (C_dem1), and the ΔV _BE generator 130 operates in response to the second current steering control signal (C_str2) and the second DEM control signal (C_dem2) generated by the control unit 140. . Considering that the output terminal of the temperature sensor 100 is a digital back end (Digital Back End, 190), the temperature detection unit 110 can be said to be an analog front end of the temperature sensor 100.

Referring to FIG. 2, the PTAT current generation unit 120 includes a first current sourcing unit 121, an amplifying unit 124, and a biasing unit 127.

The first current sourcing unit 121 includes a first current source array 122 and a first switch array 123.

Figure 5 is an example of a first current sourcing unit and an amplifying unit.

Referring to FIG. 5, the first current source array 122 has a plurality of current sources (CS11, CS12, ~ CS1(n+1)), and the current control voltage (Vc) output from the amplification unit 124 ), the size of the current of each current source is adjusted and output (s11~s1(n+1), n is a natural number).

The first switch array 123 groups the currents (s11 to s1(n+1)) output from the first current source array 122 in response to the DEM first control signal (C_dem1) at a ratio of 1:n to 2 It includes a plurality of switches (Sw11, Sw12 ~ Sw1(n+1)) that switch to nodes (N1, N2). ㅇFor example, the current output from the first current source (CS11) is supplied to the first node (N1), and the first current source (CS11) among a plurality of current sources (current sources, CS11, CS12, ~ CS1 (n+1)) ), the sum of the currents output from the remaining current sources (CS12 ~ CS1 (n+1)) is supplied to the second node (N2), so that the ratio of the current supplied to the first node (N1) and the second node (N2) is Make it 1:n.

The types of the plurality of current sources are adjusted in response to the first current steering control signal C_str1 output from the control unit 140. Here, the type of current source includes a current source that actually supplies current (sourcing current source) and a current source that receives current (sinking current source). Since the technique of changing the type of the current source in response to the first current steering control signal (C_str1) is obvious to those skilled in the art of circuit technology, it will not be described in detail here.

DEM (Dynamic Element Matching), which is a dynamic element matching, is a technology that equalizes the probability of use of elements by randomly selecting elements or using elements sequentially. In the present invention, for convenience of explanation, elements are used sequentially without exception. This is explained as a representative example.

DEM The first control signal (C_dem1) sequentially alternately switches a plurality of switches (Sw11, Sw12 ~ Sw1 (n+1)), thereby maintaining the ratio of the output current of 1:n, while maintaining the ratio of the plurality of current sources. (CS11, CS12, ~ CS1(n+1)) can be dynamically averaged.

In order to maintain the ratio of 1:n, for example, the first current source (CS11) is selected as the current source corresponding to the current ratio of 1 at a specific operating time, and the remaining current sources (CS12) are selected in response to the first current source (CS11). ~CS1(n+1)) are grouped into one group and operated.

During the subsequent operation time, the second current source (CS12) is selected as the current source corresponding to the current ratio of 1, and the remaining current sources (CS11, CS13 ~ CS1 (n+1)) are selected as one group corresponding to the second current source (CS12). It operates by tying it together.

Continuing to sequentially select the third current source (CS13) to the (n+1)th current source (CS1(n+1)) as the current source corresponding to the current ratio 1, the remaining current sources that were not selected during the corresponding operation time are added to n. will be selected as the corresponding current source.

Referring to FIG. 5 , the amplifier 124 includes a first chopper circuit 125 and an amplifier 126.

The amplifier 126 amplifies the signal input to the differential input terminals (V+, V-) to generate a current control voltage (Vc), and the first chopper circuit 125 generates a current control voltage (Vc), and the first chopper circuit 125 receives two switch control signals (f1, The polarity of the amplifier 126 is dynamically changed in response to one of the switch control signals (f2) (f1).

Figure 6 is an example of a biasing unit.

Referring to FIG. 6, the biasing unit 127 includes a second switch array 128 and a first bias circuit 129.

The first bias circuit 129 dynamically connects the PTAT resistance (R _PTAT ) included therein in response to the two switch control signals (f1, f2), and also includes a beta compensation resistor (beta) included therein. R _B , not shown) is dynamically converted to generate four node voltages (N3, N4, N5, N6).

Referring to FIG. 6, the first bias circuit 129 includes a first PTAT resistor (R _PTAT1 ) installed between the third node (N3) and the fourth node (N4), the sixth node (N6), and the fifth node ( A second PTAT resistor (R _PTAT2 ) installed between N5), a first BJT (Q1) with one terminal connected to the fourth node (N4) and the other terminal connected to the ground voltage (GND), one terminal connected to the fifth node A second BJT (Q2) connected to (N5) and the other terminal connected to the ground voltage, a beta compensation resistor (R _B ) connecting the bases of the first BJT (Q1) and the second BJT (Q2), and a first A 41st switch (Sw41) for switching the base of the first BJT (Q1) to the ground voltage (GND) in response to the switch control signal (f1) and a second BJT (Q2) in response to the second switch control signal (f2) It includes a 42nd switch (Sw42) that switches the base of to the ground voltage (GND).

While the first switch control signal (f1) is activated, the base of the first BJT (Q1) is connected to the ground voltage (GND), and the base of the second BJT (Q2) is grounded via the beta compensation resistor (R _B ). Connected to voltage (GND). Conversely, while the second switch control signal (f2) is activated, the base of the second BJT (Q2) is connected to the ground voltage (GND), and the base of the first BJT (Q1) is connected to the beta compensation resistor ( _RB ). Connected to ground voltage (GND).

Through this process, the polarity of the beta compensation resistor (R _B ) can be dynamically converted, resulting in mismatch of the first BJT (Q1) and second BJT (Q2) and offset of the amplifier 163. can be averaged.

In the present invention, when applying DEM to the PTAT current generator 120, even if process dispersion exists between a plurality of current sources, the dispersion can be averaged in the same manner as described above. At this time, the current (I _E1 ) flowing through the emitter of the first BJT (Q1) can be expressed as Equation 1.

In Equation 1, k is the Boltzmann Constant, T is the absolute value of temperature, and q means the amount of charge. The emitter current (I _E1 ) of the first BJT (Q1) is related to the distribution of n, and if the distribution of n is small, a current with high precision can be obtained.

Referring to FIG. 6, the second switch array 128 includes a plurality of switches Sw21, Sw22 to Sw28.

The 21st switch (Sw21) switches the first node (N1) to the third node (N3), and the 22nd switch (Sw22) switches the positive input terminal (V+) of the amplifier 126 to the third node (N3). , the twenty-third switch (Sw23) switches the second node (N2) to the fourth node (N4), and the twenty-fourth switch (Sw24) switches the positive input terminal (V+) of the amplifier 126 to the fourth node (N4). Switching to the node (N4), the 25th switch (Sw21) switches the negative input terminal (V-) of the amplifier 126 to the 5th node (N5), and the 26th switch (Sw26) switches to the second node ( N2) switches to the fifth node (N5), the 27th switch (Sw27) switches the negative input terminal (V-) of the amplifier 126 to the 6th node (N6), and the 28th switch (Sw28) switches the first node (N1) to the sixth node (N6), respectively.

The 21st switch (Sw21), the 22nd switch (Sw22), the 25th switch (Sw25), and the 26th switch (Sw26) perform a switching operation in response to the first switch control signal (f1), and the 23rd switch (Sw23) ), the 24th switch (Sw24), the 27th switch (Sw27), and the 28th switch (Sw28) perform switching operations in response to the second switch control signal (f2).

Referring to FIG. 6, the second switch array 128 alternately connects two nodes (N1, N2) to two nodes (N3, N6) in response to two switch control signals (f1, f2), You can see that each one of the four nodes (N3 to N6) is selectively connected to the differential input terminal (V+, V-).

The positive input terminal (V+) of the amplifier 126 is connected to the third node (N3) when the first switch control signal (f1) is activated, and is connected to the fourth node (N4) when the second switch control signal (f2) is activated. ) is connected to. A first PTAT resistor (R _PTAT1 ) is installed between the third node (N3) and the fourth node (N4).

The negative input terminal (V-) of the amplifier 126 is connected to the fifth node (N5) when the first switch control signal (f1) is activated, and to the sixth node (N5) when the second switch control signal (f2) is activated. It is connected to N6). A second PTAT resistor (R _PTAT2 ) is installed between the fifth node (N5) and the sixth node (N4).

As described above, the PTAT resistance (R _PTAT ) connected to the two input terminals (V+ & V-) of the amplifier 126 is dynamically converted by the two switch control signals (f1 & f2) that are activated alternately. can do.

Referring again to FIG. 2, the ΔV _BE generator 130 includes a second current sourcing unit 131 and a second bias circuit 134.

Figure 7 is an example of a second current sourcing unit and a second bias circuit.

Referring to FIGS. 2 and 7 , the second current sourcing unit 131 includes a second current source array 132 and a third switch array 133.

The second current source array 132 includes a plurality of current sources (CS21, CS22 ~ CS1 (m+1)), and each current source (CS21, CS22) is responsive to the current control voltage (Vc) output from the amplification unit 124. ~ CS1 (m + 1)) adjusts the size of the current and outputs (s21 ~ s2 (m + 1), m is a natural number), and responds to the first current steering control signal (C_str1) output from the control unit 140. to adjust the types of multiple current sources. Here, the type of current source includes a current source that actually supplies current and a current sink that receives current.

Referring to FIG. 7, the third switch array 133 changes the current (s21 to s2(m+1)) output from the second current source array 122 in response to the DEM second control signal (C_dem2) to 1: It includes a plurality of switches (Sw31, Sw32 ~ Sw3(m+1)) grouped at a ratio of m and switching to two nodes (V _{BE _L} , V _{BE _R} ).

Here, the DEM second control signal (C_dem2) alternately switches a plurality of switches (Sw21, Sw22 ~ Sw2(m+1)) sequentially, so that the output current ratio maintains the ratio of 1:m, and Allows dynamic averaging of current sources (CS21, CS22, ~ CS2(m+1)). In order to maintain the ratio of 1:m, for example, after operating the remaining current sources (CS22 to CS2 (m+1)) as one group in response to the first current source (CS21) at a specific operation time, During the subsequent operation time, the remaining current sources (CS21, CS23~CS2(m+1)) will be operated in a way that corresponds to the second current source (CS22) and grouped into one group.

It is described that the first current source array 122 and the second current source array 132 adjust the current at a ratio of 1:n and 1:m, respectively, but n and m can be set arbitrarily, depending on the embodiment. n and m can also be set to the same value.

Referring to FIG. 7, the second bias circuit 134 includes two BJTs (Q3, Q4). The third BJT (Q3) has one end connected to the VBEL node (V _{BE_L} ) and the other end connected to the ground voltage (GND), and the fourth BJT (Q4) has one end connected to the VBER node (V _{BE_R} ). Each base of the third BJT (Q3) and fourth BJT (Q4) is connected to the ground voltage (GND). That is, the second bias circuit 134 determines the voltage levels of the two nodes ₍ V _{BE_L} , V _{BE_R} ) using _the BJT included therein.

The base-emitter voltage (V _{BE _L} & V _{BE _R} ) of two BJTs (Q3, Q4) can be expressed as Equation 2 below.

In Equation 2, Is means the saturation current of two BJTs (Q3, Q4).

Additionally, the difference (ΔV _{BE _ RL} ) between the base-emitter voltages (V _{BE _L} & V _{BE _R} ) of two BJTs (Q3, Q4) can be expressed as Equation 3.

FIG. 8 is an example of the multiplexer shown in FIG. 2.

Referring to FIGS. 2 and 8, the multiplexer 150 generates two conversion target voltages (V _{BE _L} , V _{BE _R} ) generated by the ΔV _BE generator 130 in response to the multiplexer control signal (M_con) from the outside. Two conversion input signals (VIP, VIN) are generated by switching the applied calibration voltage (V_cal) and ground voltage (GND).

The first conversion input voltage (VIP) is selected as one of the two conversion target voltages (V _{BE _L} , V _{BE _R} ) in response to the multiplexer control signal (M_con), and the second conversion input signal (VIN) is selected as one of the multiplexer control signal (M_con). In response to M_con), the conversion target voltage that is not selected as the first conversion input signal (VIP) among the two conversion target voltages (V _{BE _L} , V _{BE _R} ) is selected, thereby generating the ΔV _BE generator 130. The distribution of the two conversion target voltages (V _{BE _L} , V _{BE _R} ) can be averaged.

When the multiplexer 150 selects two conversion target voltages (V _{BE _L} , V _{BE _R} ), the voltage generated by the temperature sensor 100 is used as an input to the signal conversion unit 160 to detect the actual temperature. When switching the calibration voltage (V_cal) and ground voltage (GND), it is time to calibrate the temperature sensor 100.

Referring again to FIG. 2, the signal conversion unit 160 generates an analog signal in response to the DEM third control signal (C_dem3) and the chopping control signal (Fch & Fchb) generated by the control unit 140 constituting the temperature detection unit 110. Two bit stream signals (BS & , Bit Stream) is created. The signal conversion unit 160 can be implemented in the form of a charge balancing Delta-Sigma ADC. In the present invention, the input terminal of the multiplexer 150 and the ADC circuit 162, which will be described later, are controlled according to the bit stream (BS) generated at the output terminal of the signal conversion unit 160.

Figure 9 is an example of a signal conversion unit.

Referring to FIG. 9, the signal conversion unit 160 includes a second chopper circuit 161, an ADC circuit 162, and a third chopper circuit 163.

The second chopper circuit 161 chops the two conversion input signals (VIP, VIN) in response to the first chopping control signal (Fch) applied from the outside, and the third chopper circuit 163 chops the first chopping control signal (Fch) applied from the outside. 2 In response to the chopping control signal (Fchb), the two signals (Vint1, Vint2) output from the ADC circuit 162 are chopped to produce two bitstreams (BS & ) is created.

The ADC circuit 162 includes an amplifier 163, a plurality of capacitors (Cs1 to Csw, Cint), and a plurality of sixth switches (Sw61 to Sw70).

Between one output terminal of the second chopper circuit 161 and the positive input terminal (+) of the amplifier 163, a plurality of capacitor and switch pairs (Cs1:Sw61, Cs2:Sw61 ~ Csw:Sw63, w is a natural number) are connected in series. are installed in parallel, and a pair of capacitors and switches (Cs1:Sw64, Cs2:Sw65 ~ Csw:Sw66) are installed between the other output terminal of the second chopper circuit 161 and the negative input terminal (-) of the amplifier 163. Multiple units are installed in parallel.

Between the positive input terminal (+) of the amplifier 163 and the first output terminal (Vint1) of the amplifier 163, a pair of a 68th switch (Sw68) and a capacitor (Cint) connected in series are connected in parallel with the 67th switch (Sw67). connected. Between the negative input terminal (-) of the amplifier 163 and the second output terminal (Vint2) of the amplifier 163, a pair of a 69th switch (Sw69) and a capacitor (Cint) connected in series are connected in parallel with the 70th switch (Sw70). connected.

The plurality of switches (Sw61 to Sw66) operate in response to the DEM third control signal (C_dem3). For example, by sequentially selecting the 61st switch (Sw61) to the 63rd switch (Sw63), the plurality of capacitors (Cs1) As ~Csw) are used sequentially, the gain determined by the feedback capacitor (Cint) and the input capacitor (Cs) can average the gain error according to the distribution of the input capacitor (Cs).

Figure 10 is an example of the output bit stream and control signal of the signal conversion unit and the waveform applied to the signal conversion unit.

Referring to FIG. 10, when the output bit stream (BS) of the signal conversion unit 160 has a logic low value (BS=L), two BJTs (Q3, The difference (ΔV _{BE _ RL} ) voltage between the base-emitter voltages (V _{BE _L} & V _{BE _R} ) of Q4) is applied, and the output bit stream of the signal conversion unit 160 has a logic high value. When (BS=H), it can be seen that the base-emitter voltages (V _{BE _L} & V _{BE _R} ) of the two BJTs (Q3, Q4) are applied as the input of the signal conversion unit 160.

The multiplexer control signal generator 170 generates two conversion signals (BS & ) is used to generate the multiplexer control signal (M_con).

The output unit includes a decimation filter 180 and a digital back end 190.

The decimation filter 180 converts two conversion signals (BS & ) Adjust the band width of one of the signals (BS).

The digital back end 190 outputs a digital signal with an adjusted bandwidth to the outside.

The signal (DOUT) output from the digital back end 190 can be expressed as Equation 4.

Here, u means the number of signals input when the BS is in the logic low (left) state in FIG. 10, v means the number of signals input when the BS is in the logic high (right) state, and w represents the number of input capacitors (Cs).

The core idea of the present invention is, using the embodiments shown in FIGS. 1 to 9,

- Dynamically connect the two PTAT resistors (R _PTAT1 , R _PTAT2 ) constituting the PTAT current generator 120, dynamically change the polarity of the amplifier 126, and use a beta compensation resistor (R _B , not shown) is converted dynamically,

- Dynamically averaging a plurality of current sources (CS11 to CS1 (n+1)) included in the first current sourcing unit 121 constituting the PTAT current generator 120,

- Dynamically averaging a plurality of current sources (CS21 to CS2 (m+1)) included in the second current sourcing unit 131 constituting the ΔV _BE generating unit 130,

- By averaging the distribution of the two conversion target voltages (V _{BE_L} , V _{BE_R} ) generated by the ΔV _BE generator 130 using the multiplexer 150, that is, the distribution of the two BJTs (Q3 & Q4),

It is possible to optimize the precision of the detection temperature regardless of the distribution of electrical characteristics of the components constituting the temperature sensor 100.

In the above, the technical idea of the present invention has been described along with the accompanying drawings, but this is an exemplary description of a preferred embodiment of the present invention and does not limit the present invention. In addition, it is clear that anyone skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

110: Temperature detection unit
120: PTAT current generator
121: First current sourcing unit
122: first current source array 123: first switch array
124: Amplification unit
125: first chopper circuit 126: amplifier
127: Biasing unit
128: second switch array 129: first bias circuit
130: ΔV _BE generation unit
131: Second current sourcing unit
132: second current source array 133: third switch array
140: control unit
141: DEM control unit 142: current steering unit
150: multiplexer
160: Signal conversion unit
161: second chopper circuit 162: ADC circuit
163: Third chopper circuit
170: Multiplexer control signal generator
180: Decimation filter
190: Digital back end

Claims (9)

By using two switch control signals applied from the outside to control the connection between two BJTs and an amplifier whose base-emitter voltage level changes depending on the temperature, the errors of the two BJTs are averaged, and the temperature of the two BJTs is adjusted. a temperature detection unit that outputs a first base-emitter voltage, a second base-emitter voltage, and a third DEM control signal corresponding to two different BJTs in response to the magnitude of the current adjusted in response to the change;
A multiplexer that dynamically converts the first base-emitter voltage and the second base-emitter voltage in response to a multiplexer control signal and alternately switches them to a first output terminal and a second output terminal;
In response to two control signals, the third DEM control signal, and the chopping control signal, the two voltages output from the first and second output terminals of the multiplexer are dynamically switched and simultaneously converted into digital signals to produce a bit stream signal. A signal conversion unit that generates; and
An output unit that adjusts the bandwidth of the bit stream signal and outputs it to the outside.
Temperature sensor with reduced dispersion and improved precision. In claim 1, the temperature detection unit,
a PTAT current generator that outputs a current control voltage in response to the two switch control signals, the first current steering control signal, and the first DEM control signal;
a ΔV _BE generator generating the first base-emitter voltage and the second base-emitter voltage in response to the current control voltage, the second current steering control signal, and the second DEM control signal; and
A control unit that generates the first current steering control signal, the second current steering control signal, the first DEM control signal, the second DEM control signal, and the third DEM control signal.
Temperature sensor with reduced dispersion and improved precision. In claim 2, the PTAT current generator,
A first current that supplies a current having a current ratio of 1:n (n is a natural number) to the first node and the second node in response to the current control voltage, the first current steering control signal, and the first DEM control signal. Sourcing Department;
an amplifier that generates the current control voltage in response to a first switch control signal among the two switch control signals and a voltage applied to a positive input terminal and a negative input terminal; and
In response to the two switch control signals, the PTAT resistor is dynamically connected, the beta compensation resistor is dynamically converted, and the two voltages selected using the current supplied from the first node and the second node are connected to the amplification unit. Biasing part supplied to positive input terminal and negative input terminal
Temperature sensor with reduced dispersion and improved precision. In claim 3, the first current sourcing unit,
A first current source array comprising a plurality of current sources, each of which adjusts the size of the current in response to the current control voltage and outputs it; and
A plurality of switches for grouping a plurality of current sources output from the first current source array into two groups with a current ratio of 1:n in response to the first DEM control signal and switching them to the first node and the second node, respectively. A first switch array comprising
Temperature sensor with reduced dispersion and improved precision. In claim 3, the amplification unit,
an amplifier that generates the current control voltage by amplifying the voltage input to the positive input terminal and the negative input terminal; and
A first chopper circuit that dynamically changes the polarity of the amplifier in response to the first switch control signal.
Temperature sensor with reduced dispersion and improved precision. In claim 3, the biasing unit,
A first PTAT resistor installed between the third node and the fourth node, a second PTAT resistor installed between the sixth node and the fifth node, and a first terminal having one terminal connected to the fourth node and the other terminal connected to the ground voltage. BJT, a second BJT with one terminal connected to the fifth node and the other terminal connected to a ground voltage, a beta compensation resistor connecting the bases of the first BJT and the second BJT, and among the two switch control signals A 41st switch for switching the base of the first BJT to ground voltage in response to a first switch control signal and a 41st switch for switching the base of the second BJT to ground voltage in response to a second switch control signal among the two switch control signals. a first bias circuit including a forty-second switch; and
A 21st switch switching the first node to the third node, a 22nd switch switching the positive input terminal of the amplifier to the third node, and a 23rd switch switching the second node to the fourth node. , a twenty-fourth switch for switching the positive input terminal of the amplifier to the fourth node, a twenty-fifth switch for switching the negative input terminal of the amplifier to the fifth node, and a twenty-fourth switch for switching the second node to the fifth node. It includes 26 switches, a 27th switch for switching the negative input terminal of the amplifier to the sixth node, and a 28th switch for switching the first node to the sixth node,
The 21st switch, the 22nd switch, the 25th switch, and the 26th switch perform a switching operation in response to the first switch control signal, and the 23rd switch, the 24th switch, the 27th switch, and The 28th switch is a second switch array that performs a switching operation in response to the second switch control signal.
Temperature sensor with reduced dispersion and improved precision. In claim 2, the ΔV _BE generator,
It is provided with a plurality of current sources, each of the plurality of current sources is a second current source array that adjusts the size of the current in response to the current control voltage and outputs the plurality of current sources in response to the DEM second control signal. A plurality of switches are grouped into two groups of 1:m (m is a natural number) and each switches to a node outputting the first base-emitter voltage and a node outputting the second base-emitter voltage. a second current sourcing unit including a third switch array; and
A third BJT, one end of which is connected to the node that outputs the first base-emitter voltage and the other end of which is connected to a ground voltage, and one end of which is connected to the node that outputs the second base-emitter voltage. a second bias circuit including 4 BJTs,
A temperature sensor with reduced dispersion and improved precision, wherein each base of the third BJT and the fourth BJT is connected to a ground voltage. In claim 1, the signal conversion unit,
a second chopper circuit that chops two voltages output from the first and second output terminals of the multiplexer in response to a first chopping control signal among the chopping control signals;
an ADC circuit that converts two analog voltages output from the second chopper circuit into two digital signals; and
A third chopper circuit that generates the bit stream by chopping two digital signals output from the ADC circuit in response to a second chopping control signal among the chopping control signals.
Temperature sensor with reduced dispersion and improved precision. In claim 8, the ADC circuit is:
Includes an amplifier,
A plurality of pairs of first capacitors and first switches connected in series between the positive input terminal of the amplifier and the first output terminal of the second chopper circuit are installed in parallel,
A plurality of pairs of a second capacitor and a second switch connected in series between the negative input terminal of the amplifier and the second output terminal of the second chopper circuit are installed in parallel,
A third capacitor and a 68th switch connected in series between the positive input terminal and the negative output terminal of the amplifier are installed, and a 67th switch connected in parallel with the third capacitor and the 68th switch is installed,
A fourth capacitor and a 69th switch connected in series between the negative input terminal and the positive output terminal of the amplifier and a 70th switch connected in parallel with the fourth capacitor and the 69th switch are installed,
The first switch and the second switch operate in response to the third DEM control signal, the 67th switch and the 70th switch operate in response to the first control signal of the two control signals, and the 68 The switch and the 69 switch operate in response to a second control signal among the two control signals,
The first control signal and the second control signal are two-phase non-overlap signals,
The switch control signal has a period that is an integer multiple of the chopping control signal, and the control signal has a period that is an integer multiple of the switch control signal. A temperature sensor with reduced dispersion and improved precision.