JP3439894B2 - Driver circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to
Output that switches multiple voltages in any order
It is related to a circuit. [0002] 2. Description of the Related Art A device under test is
In order to evaluate the performance of the IC which is a chair,
Output by switching multiple voltages to the lead terminals one after another
Driver circuit. Conventionally, this driver circuit has a structure as shown in FIG.
Circuit was used. FIG. 5 is a circuit diagram showing the configuration of a conventional driver circuit.
It is a road map. In FIG. 5, a first current source 11 has a transformer.
Transistor Q_a1Of the transistor Q
_a1Of the first diode bridge 13
Connected to child. The terminal a of the first diode bridge 13 and
A transistor Q is connected to the opposite c terminal. _a2Collector C contacts
Connected to the transistor Q_a2Is the second current source
12 is connected. The transistor Q_a1Base B
Transistor Q_a1Control power to control ON / OFF of
Source V_a1Are connected, and the transistor Q_a2Base B
Transistor Q_a2Control power to control ON / OFF of
Source V_a2Is connected. [0008] To the terminal b of the first diode bridge 13
Is the output voltage V of the driver circuit._OThe first source of
Output power supply V₁Is connected. In addition, the first Daio
Bridge 13 and first output power supply V₁Wiring material between
The inductor L1 of the sample is equivalently connected.
In addition, it faces the terminal b of the first diode bridge 13.
Terminal d is connected to the output terminal 17 of the driver circuit.
You. Here, the first diode bridge 13 is
It is composed of four diodes, from terminal a to terminal b and
Die so that forward current flows toward the d terminal.
The ode is connected and goes from terminal b and terminal d to terminal c.
Each other diode so that forward current flows
It is connected. A transistor is provided between the two current sources.
Q_b1, A second diode bridge 14, and a transistor
TA Q_b2Is the transistor Q_a1, The first Daioh
Bridge 13 and transistor Q_a2And in parallel, as well
Connection is made, and these transistors Q_b1, Q_b2No
Source B has a control to control each ON / OFF.
Power supply V_b1, V_b2Is connected. The terminal b of the second diode bridge 14
Is the second output power supply V_TwoIs an inductor L made of wiring material, etc.
2 and the second diode bridge 14
The d terminal is connected to the output terminal 17 of the driver circuit.
You. Similarly, a transformer is provided between the two current sources.
Jista Q_c1, A third diode bridge 15, and a transformer.
Transistor Q_c2Is the transistor Q_a1, The first da
Iod bridge 13 and transistor Q_a2And parallel
A similar connection is made to these transistors Q_c1,
Q_bcON / OFF is controlled for each base B
Power supply V for_c1, V_c2Is connected. The third diode bridge 15 has a b
The terminal has a third output power V_ThreeIs the inductance due to the wiring material
Connected to the third diode bridge 1
The d terminal facing the b terminal of No. 5 is the output terminal of the driver circuit
17. Note that the second diode bridge 14 and
And the third diode bridge 15 are also connected to the first diode bridge.
The configuration is the same as that of the ridge 13, and the output terminal 17 has the first
Diode bridge 13, second diode bridge 1
4 and connection wiring from the third diode bridge 15
Stray capacitance C_SIs equivalently inserted between the
Have been. In such a configuration, a control hand (not shown)
Depending on the stage, for example, the first output power V ₁Is selected,
Control power supply V_a1, V_a2Transient depending on the voltage output from
Star Q_a1, Q_a2Turns ON. Transistor Q_a1, Q_a2But
When turned on, the first current source 11 and the second current source 12
As a result, the current Ia is supplied to the first diode bridge 13.
Supplied to the output terminal 17 of the driver circuit.
The first output power supply V₁The voltage of
Is output. Similarly, the control power supply V_b1, V_b2Output from
Transistor Q depending on the applied voltage._b1, Q_b2Turns on
From the output terminal 17 of the driver circuit.
The second output power supply V_TwoVoltage
Control power supply V_c1, V_c2Depending on the voltage output from
Transistor Q_c1, Q_c2Is ON, the driver circuit
From the output terminal 17 via the third diode bridge 15
And the third output power V_ThreeIs output. Incidentally, the output voltage V_OBut for example the second
Output power supply V_TwoTo the first output power supply V₁Change to
In the case of conversion, the amplitude (the first output power V₁Voltage and the second
Output power supply V_TwoVoltage difference) V_SOutput voltage V
_OFIG. 6 shows the relationship of the voltage switching time t of FIG.
become. FIG. 6 shows the output voltage of the driver circuit shown in FIG.
Graph showing the relationship between voltage switching time and voltage amplitude
It is. As shown in FIG._SVoltage off for
The switching time t changes linearly, and its slope is two currents.
Equivalent to the value of the current value Ia supplied from the source and the output terminal 17
Of the stray capacitance Cs (the slope is Ia / Cs)
And the larger the value of the current value Ia, the more the inclination
Also increases. However, in FIG._SIs a predetermined voltage value V
_p-p1Also shows that there is no linearity in smaller areas
ing. This is a predetermined voltage value V_p-p1Greater amplitude V
_SThen, for example, the capacity of the diode bridge and the output terminal 17
Charge storage time for stray capacitance Cs connected
And the switching time t is determined by the discharge time,
Constant voltage value V_p-p1In the following, transistor switching
Speed, ON / O of each diode of diode bridge
This is because the FF time becomes dominant. [0021] SUMMARY OF THE INVENTION As described above,
In the driver circuit, the output voltage V_OFigure 5
The voltage Vb at the terminal b of the diode bridge shown in FIG.
It was fluctuating. The generation of the spike voltage
The inductor L
1, L2, and L3 due to the occurrence of a potential difference at both ends.
You. The peak value of the spike voltage is represented by V_SPTo be
And the spike voltage V_SPIs the output voltage V _OSuperimposed on the output
It was output as waveform distortion from the terminal. For example, the second output power source V_TwoFrom the voltage of the first
Output power V₁Output voltage V _OThe place to switch
In this case, as shown in FIG._SIs the spike voltage V_SPTo
When the amplitude is large enough,_SSpike against
Voltage V_SPIs relatively small, so distortion of the output waveform is
There is no problem. However, as shown in FIG._S
Is small, that is, the amplitude V_SIs the spike voltage V_SPof
When the value is close to the value, the distortion of the output waveform increases.
U. In particular, the transistor Q_a1And Q_a2ON / O
If the timing of the FF is off, the first diode
Spike voltage V generated at terminal b of the bridge_SPFurther
And the distortion of the output waveform becomes even greater.
U. This means that transistor Q_b1And Q_b2ON / OF
If the timing of F is shifted or the transistor Q_c1And Q _c2
When the ON / OFF timing of the
Of the auto bridge 14 and the third diode bridge 15
Spike voltage V appearing at terminal b_SPThe same applies to
You. Spike voltage V_SPIs the size of the first current source
And the value of the current Ia supplied from the second current source
The spike voltage V increases as the current Ia increases._SPAlso
It was getting bigger. The present invention has the above-mentioned prior art.
To solve the problem
Reduce waveform distortion when switching pressure and measure IC performance
To provide a driver circuit that can be performed accurately
Aim. [0028] [MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
The driver circuit of the present invention includes a plurality of dies connected in parallel.
A voltage set to an arbitrary voltage
A source is connected, and among the plurality of diode bridges,
Passing current through one selected diode bridge
Output the voltage of the power supply connected to the diode bridge.
In the driver circuit to be activated,
Variable current to change the current supplied to the diode bridge
Flow source and any two
One diode bridge before switching
Voltage and switching of power supply connected to diode bridge
The voltage of the power supply connected to the other diode bridge after
And the voltage difference is larger than a predetermined value.
Sometimes, the power supplied to the other diode bridge
A control signal for outputting the current at a predetermined constant value.
Output to the flow source, and when the voltage difference is equal to or less than a predetermined value.
The current supplied to the other diode bridge
Control signal for changing the voltage in proportion to the voltage difference.
Having a voltage difference detection unit for outputting to the variable current source
It is characterized by. [0029] The driver circuit configured as described above
The voltage difference detector detects the selected diode bridge.
The voltage of the connected power supply and one of its diode bridges
The power of the power supply connected to the previously selected diode bridge
The voltage difference from the voltage is detected and the variable current source detects the detected voltage.
The current supplied to the diode bridge varies in proportion to the difference.
To Therefore, when the voltage difference is small,
, The supply current from the variable current source also decreases. S
Since the peak voltage depends on the value of the supply current,
Reduce the spike voltage generated at the connection point between the bridge and the power supply.
Waveform distortion when switching the output voltage.
Become smaller. [0032] BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Will be explained. (First Embodiment) A driver circuit according to the present invention
Output voltage V in addition to the conventional configuration_OMultiple sources of
Detects the voltage difference between any two of the output power supplies
A voltage difference detection unit to detect current difference
Output current can be varied by control voltage output from the section
To a variable current source. Other configurations are the same as before
It is like. In the following, three types of voltages are switched.
Output will be explained, but voltage types are limited to three
It is not something to be done. The same configuration as the following circuit
Switch between more types of voltage
Needless to say, it can output. FIG. 1 shows the configuration of the driver circuit of the present invention.
It is a circuit diagram. FIG. 2 shows the voltage difference detection unit shown in FIG.
FIG. 6 is a diagram of the control characteristic of the first embodiment of FIG.
4 is a graph showing a state of a current of a current source. In FIG. 1, the first variable current source 1
Transistor Q_a1Is connected to the emitter E of the transistor
Q_a1The collector C of the first diode bridge 3
Connected to child. A pair with the terminal a of the first diode bridge 3
The opposite terminal c has a transistor Q_a2Collector C is connected
And the transistor Q_a2E is the second variable current
Connected to source 2. Transistor Q_a1Transient on base B
Star Q_a1Power supply V for controlling ON / OFF of_a1
Are connected, and the transistor Q_a2Transient on base B
Star Q_a2Power supply V for controlling ON / OFF of_a2
Is connected. To the terminal b of the first diode bridge 3
Is the output voltage V_OOutput power supply V as a supply source for₁But
It is connected. Note that the first diode bridge 3 and
First output power supply V₁Between the wiring material
Is connected equivalently. Also, the first die
The d terminal facing the b terminal of the auto bridge 3 is a driver
It is connected to the output terminal 7 of the circuit. Here, the first diode bridge 3 is
From the a terminal to the b terminal and d
Each diode is connected so that a forward current flows to the terminal.
Connected, forward direction from terminal b and terminal d to terminal c
Each other diode is connected so that current flows.
ing. Further, a transistor is provided between the two variable current sources.
Star Q_b1, The second diode bridge 4 and the transistor
Star Q_b2Is the transistor Q_a1, The first Daio
Bridge 3 and transistor Q_a2And in parallel, as well
Connections are made. These transistors Q_b1, Q_b2
To control each ON / OFF on the base B
Control power supply V_b1, V_b2Is connected. Second Daio
The second output power supply V_TwoBut
Connected through an inductor L2 of wire material,
The d terminal of the diode bridge 4 is the output terminal of the driver circuit.
Child 7. In the same manner, a current is applied between the two variable current sources.
Transistor Q_c1, A third diode bridge 5, and
Transistor Q_c2Is the transistor Q_a1The first
Diode bridge 3 and transistor Q_a2And parallel
A similar connection is made. These transistors Q
_c1, Q_c2ON / OFF control for each base B
Control power supply V_c1, V_c2Is connected. Third
The third output power supply V is connected to the terminal b of the diode bridge 5 of FIG.
_ThreeAre connected via an inductor L3 made of a wiring material.
D facing the terminal b of the third diode bridge 5
The terminal is connected to the output terminal 7 of the driver circuit. The first output power supply V₁, And the second output
Power supply V_TwoDetects the voltage difference and detects two variable currents
The value of the current Ia supplied from the source is changed according to the voltage difference.
The voltage difference detector 6 to be connected is connected. First variable current
The first variable current source 2 and the second variable current source 2
Change the value of the output current Ia according to the control signal
You. Note that the second diode bridge 4 and
The configuration of the third diode bridge 5 is the first diode
Same as bridge 3. Also, the output terminal of the driver circuit
The first diode bridge 3 and the second diode
From the diode bridge 4 and the third diode bridge 5
Stray capacitance C due to the wiring connection_SIs equivalent to the ground potential
Is inserted. In such a configuration, for example, the output voltage
V_OIs the second output power supply V_TwoVoltage to the first output power supply
V₁When the voltage is switched to the voltage of
Output power supply V₁And the second output power supply V_TwoAmplitude V_S(Voltage
Difference). Here, the amplitude V_SIs a predetermined voltage V_P-P1Than
If it is larger, the voltage difference detection unit 6
Current I to be supplied to₁Becomes a predetermined constant current Ia
The first variable current source 1 and the second variable current source 2
To output a control signal. On the other hand, the amplitude V_SIs a predetermined voltage V_P-P1below
In this case, the voltage difference detector 6 detects the current Ia as shown in FIG.
Width V_SThe first variable current sources 1 and
A control signal is output to the second variable current source 2. At this time, the amplitude V_SVoltage switching for
FIG. 3 shows the relationship of the time t. FIG. 3 shows the amplitude of the driver circuit shown in FIG.
6 is a graph showing characteristics of voltage switching time with respect to the voltage switching time. As shown in FIG. 3, when the current Ia decreases,
The driver circuit operates so that the voltage switching time t is delayed.
Work, but the predetermined voltage V_P-P1The following amplitude V_Sso
Is switched off by the switching speed of the transistor etc.
Since the replacement time t is dominant, the current Ia is reduced.
It is hardly a problem. In this way, the current is supplied from the variable current source.
When the current Ia is reduced, it depends on the value of the current Ia.
Spike voltage V_SPOutput voltage switching
Output waveform distortion is small and IC performance measurement is correct.
I can do it for sure. In this embodiment, the first output power supply V₁
And the second output power supply V_TwoAmplitude V_S(Voltage difference)
Although the case where the detection is performed by the output unit 6 has been described, the amplitude V_SInspection
The output may be changed as needed, for example, the second output power.
Source and third output power amplitude V_SMay be detected.
Of the first output power, the second output power, and the third output power.
Amplitude V between each_SMay be detected. And that
Amplitude V_SOf the first current source 1 and the second current source
Of the current Ia supplied from the current source 2 is controlled. (Second Embodiment) In the first embodiment, the amplitude V_SBut
Predetermined voltage V_P-P1Supplied from the variable current source only when
Current Ia to amplitude V_SDecreased in proportion to In this embodiment, the predetermined voltage V_P-P1The following
Width V_SIn addition, the current Ia supplied from the variable current source is
All amplitudes V_SShould be changed in proportion to
You. Other circuit configurations are the same as in the first embodiment.
Therefore, the description is omitted. FIG. 4 shows a second embodiment of the voltage difference detecting section shown in FIG.
It is a figure of the control characteristic of an example,
It is a graph which shows a mode of an electric current. Supplied from a variable current source as shown in FIG.
Amplitude V_SControl that always changes in proportion to
Also the amplitude V_SIn a region where is small, the current Ia decreases.
Is controlled in the same manner as in the first embodiment.
Spike voltage V depending on_SPCan be reduced,
Reduce output waveform distortion when switching output voltage
Can be. [0057] The present invention is configured as described above.
Therefore, the following effects can be obtained. Diode bridge according to control signal
Variable current source to change the current supplied to
Any two diode bridges
To one of the diode bridges before switching
The voltage of the connected power supply and the other diode after switching
Detect the voltage difference from the voltage of the power supply connected to the bridge,
When the voltage difference is larger than the predetermined value, the other diode
The current supplied to the bridge is output at a predetermined constant value.
Output a control signal to the variable current source to
Is less than or equal toInSupply to the other diode bridge
Output a control signal that changes the current flowing in proportion to the voltage difference
When the voltage difference is small,
The supply current from the variable current source decreases. Therefore, the diode bridge and the power supply
The spike voltage generated at the connection point of
Waveform distortion when switching the output voltage
This allows accurate measurement of IC performance.
You.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram showing a configuration of a driver circuit according to the present invention. FIG. 2 is a graph of a control characteristic of the first embodiment of the voltage difference detecting section shown in FIG. 1, and is a graph showing a state of a current of a variable current source with respect to an amplitude. FIG. 3 is a graph showing a characteristic of a voltage switching time with respect to an amplitude of the driver circuit shown in FIG. 1; FIG. 4 is a graph showing control characteristics of a second embodiment of the voltage difference detection unit shown in FIG. 1, and is a graph showing a state of a current of a variable current source with respect to an amplitude. FIG. 5 is a circuit diagram showing a configuration of a conventional driver circuit. 6 is a graph showing a relationship between a voltage switching time and an output voltage amplitude of the driver circuit shown in FIG. 5; FIG. 7 is a diagram showing an operation of the driver circuit shown in FIG. 5 when an output amplitude is sufficiently large with respect to a spike voltage;
2A is an output waveform diagram, FIG. 2B is a current waveform diagram flowing through a diode block, and FIG. 2C is a voltage waveform diagram at a connection point between the diode block and an output power supply. 8A and 8B are diagrams showing the operation of the driver circuit shown in FIG. 5 when the output amplitude is close to the value of the spike voltage. FIG. 8A is an output waveform diagram, and FIG. FIG. 3C is a waveform diagram of a flowing current, and FIG. 3C is a voltage waveform diagram of a connection point between the diode block and the output power supply. [Description of Signs] 1 First variable current source 2 Second variable current source 3 First diode bridge 4 Second diode bridge 5 Third diode bridge 6 Voltage difference detector 7 Output terminal C _S Stray capacitance _{Q a1, Q a2, Q b1} , Q b2, Q c1, Q c2 transistor L1~L3 inductor V ₁ first output power V ₂ second output power V ₃ third output power supply V _a1, V _a2 , V _b1 , V _b2 , V _c1 , V _c2 control power supply

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H03K 17/76 G01R 31/26 G01R 31/28

Claims (1)

(57) [Claim 1] A power supply set to an arbitrary voltage is connected to each of a plurality of diode bridges connected in parallel, and one of the plurality of diode bridges is selected from the plurality of diode bridges. A driver circuit that outputs a voltage of a power supply connected to the diode bridge by flowing a current through the diode bridge; a variable current source that changes a current supplied to the diode bridge in accordance with a control signal; and Detecting the voltage difference between the voltage of the power supply connected to one diode bridge before switching and the voltage of the power supply connected to the other diode bridge after switching for any two diode bridges focused on When the difference is larger than a predetermined value, the current supplied to the other diode bridge is
A control signal to be output at a predetermined constant value is output to the variable current source, and when the voltage difference is equal to or less than a predetermined value,
A driver circuit, comprising: a voltage difference detection unit that outputs a control signal for changing a current supplied to the other diode bridge in proportion to the voltage difference to the variable current source.