CN108957288B - Test substrate suitable for multiple specification crystal oscillator - Google Patents
Test substrate suitable for multiple specification crystal oscillator Download PDFInfo
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- CN108957288B CN108957288B CN201810594963.7A CN201810594963A CN108957288B CN 108957288 B CN108957288 B CN 108957288B CN 201810594963 A CN201810594963 A CN 201810594963A CN 108957288 B CN108957288 B CN 108957288B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/2851—Testing of integrated circuits [IC]
Abstract
The invention discloses a test substrate suitable for crystal oscillators of various specifications, which comprises a power supply socket, an output socket for outputting source signals of the crystal oscillator to be tested, a test socket correspondingly and electrically connected with a test plug of a test plug board, and a test circuit arranged on the back of the test substrate. The test sockets are respectively corresponding to three test pin groups of the test substrate, a plurality of wiring terminals in the test sockets are electrically connected with input and output ends and control ends of a plurality of modules in the test circuit, and the connection control relation of the wiring terminals in the test circuit can be changed by corresponding connection with the test pin groups on the test plug board, so that the test plug board can adapt to test plug boards with different power supply types. The test substrate provides a unified power supply platform for the test plugboards with various power supply types, and is convenient for the power-up test of the crystal oscillators with various specifications.
Description
Technical Field
The invention belongs to the technical field of crystal oscillator detection, and particularly relates to a test substrate suitable for crystal oscillators of various specifications.
Background
Crystal oscillator is a crystal oscillator, which is a crystal element formed by cutting a thin sheet (called a wafer for short) from a quartz crystal according to a certain azimuth angle and adding an IC (integrated circuit) into the package. Therefore, different crystal oscillators generally have different specifications, including a size specification, a power supply voltage specification, and the like.
When the crystal oscillators of different power supply types are powered on for testing, the crystal oscillators are required to be plugged into a corresponding test plug board, and the test plug board of each power supply type can be plugged into the crystal oscillators of different specifications and sizes.
Disclosure of Invention
The invention mainly solves the technical problem of providing a test substrate suitable for test plugboards with various power supply types, and solves the problem that the test plugboards share the same power supply platform.
In order to solve the technical problems, the technical scheme adopted by the invention is to provide a test substrate suitable for various specifications of crystal oscillators, which comprises a power supply socket, an output socket and a test circuit, wherein the power supply socket is arranged on the front surface of the test substrate and is used for being connected with external direct-current voltage, the output socket is used for outputting source signals of the crystal oscillator to be tested, the test socket is correspondingly and electrically connected with a test plug pair of a test plug board, and the test circuit is arranged on the back surface of the test substrate; the test circuit comprises a power supply filter module, wherein external direct-current voltage is output into two paths after passing through the power supply filter module, the first path is directly connected as a high-voltage channel, and the second path is connected in series through a switching power supply module and an LC energy storage circuit as a low-voltage channel; the test socket comprises a first test socket with double-row 12 jacks, a second test socket with double-row 10 jacks and a third test socket with double-row 4 jacks, and the test plug board corresponds to a first test pin group with double-row 12 pins, a second test pin group with double-row 10 jacks and a third test pin group with double-row 4 pins; the first test socket comprises a high-voltage input end and is electrically connected with the output end of the high-voltage channel; the low-voltage input end is electrically connected with the output end of the low-voltage channel; the voltage common end is electrically connected with the input end of the linear power supply module; the high voltage input end is electrically connected with the voltage common end through a first corresponding test pin group on the test plugboard, or the low voltage input end is electrically connected with the voltage common end; and the linear power supply module carries out linear voltage division on the input voltage to obtain the power supply voltage of the crystal oscillator to be tested, which is inserted on the test plugboard.
In another embodiment of the test substrate suitable for multiple specifications of crystal oscillators, the external direct-current voltage is 15V, the power supply filtering module comprises a power supply filtering chip BNX025H01L, the output end of the power supply filtering chip is the direct-current voltage 15V subjected to voltage stabilization filtering, the power supply input end of the power supply filtering chip is connected with the positive electrode of the external direct-current voltage through a power switch, anti-reverse diodes are further arranged at two ends of the external direct-current voltage, a light emitting diode and a current limiting resistor are further connected in series between the power supply input end and an input grounding end, after the power switch is closed, the light emitting diode is lighted to indicate that the external direct-current voltage is connected, the output end of the power supply filtering chip outputs the direct-current voltage subjected to voltage stabilization filtering to the subsequent stage, and the three output grounding ends are grounded.
In another embodiment of the invention suitable for testing substrates of multiple specifications of crystal oscillators, the 4 jacks of the third test socket comprise a switch power supply control end and a corresponding grounding end, a low-voltage selection end and a corresponding grounding end, and the switch power supply control end is suspended or grounded through a corresponding third test pin group on the test plugboard, and the low-voltage selection end is suspended or grounded; the switching power supply module comprises a switching power supply chip TPS54327, wherein the VIN end of the switching power supply chip is electrically connected with the output end of the power supply filter chip BNX025H01L, the EN end is connected with the switching power supply control end on one hand and is also electrically connected with the VIN end through a first enabling resistor on the other hand, when the switching power supply control end is suspended, the EN end obtains an enabling signal through the first enabling resistor to enable the switching power supply chip TPS54327 to work, and when the switching power supply control end is electrically connected with a corresponding grounding end, the switching power supply chip TPS54327 does not work; the VBST end of the switch power supply chip TPS54327 is electrically connected with the SW end through a capacitor, the SW end is connected with a first output inductor in series, and the other end of the first output inductor outputs the output voltage of the switch power supply; the output voltage of the switching power supply is regulated and controlled by a voltage division RC network, the voltage division RC network comprises a first voltage division resistor connected with the output voltage of the switching power supply, the other end of the first voltage division resistor is connected with a VFB end of a TPS54327 of the switching power supply, the two ends of the first voltage division resistor are connected with a first voltage division capacitor in parallel, the VFB end is grounded through a second voltage division resistor, a third voltage division resistor and a fourth voltage division resistor which are sequentially connected in series, the third voltage division resistor and the fourth voltage division resistor are electrically connected with a low-voltage selection end, when the output voltage of a BNX025H01L of the power supply filter chip is 15V, the output voltage of the switching power supply is 6.6V when the low-voltage selection end is grounded, and when the low-voltage selection end is suspended, the output voltage of the switching power supply is 4.8V.
In another embodiment of the test substrate suitable for multiple specifications of crystal oscillators, the output voltage of the switching power supply output by the first output inductor is input to the LC energy storage circuit, the LC energy storage circuit comprises 4 parallel non-polar capacitors and energy storage inductors electrically connected with the first output inductor, one ends of the non-polar capacitors are electrically connected with the first output inductor and the energy storage inductors, the other ends of the non-polar capacitors are grounded, two ends of the energy storage inductors are respectively electrically connected with anodes of the 2 polar capacitors, and cathodes of the polar capacitors are grounded.
In another embodiment of the present invention applicable to the test substrate of multiple specifications of crystal oscillators, the second test socket includes a linear power supply enabling end and a corresponding grounding end, a first voltage division control end and a corresponding grounding end, a second voltage division control end and a corresponding grounding end, the linear power supply enabling end is suspended or grounded through a second test pin group corresponding to the test plug board, the first voltage division control end is suspended or grounded, and the second voltage division control end is suspended or grounded; the linear power supply module comprises a linear power supply chip LM1085, wherein the IN end of the linear power supply chip is electrically connected with the voltage common end of the first test socket, the ADJ end is connected with a collector electrode of a triode, an emitter electrode of the triode is grounded, the base electrode is connected with a first enabling resistor, the other end of the first enabling resistor is connected with a second enabling resistor, the other end of the second enabling resistor is also electrically connected with the voltage common end of the first test socket, and the first enabling resistor and the second enabling resistor are electrically connected with the linear power supply enabling end; when the linear power supply enabling end is suspended, the triode is conducted, the ADJ end of the chip LM1085 is grounded, and the corresponding OUT end is output by reference voltage; when the linear power supply enabling end is grounded, the triode is cut off, the ADJ end of the chip LM1085 is not grounded, and the corresponding OUT end outputs the voltage division value of the controllable resistor network; the controllable resistance network comprises a first linear voltage dividing resistor between the ADJ end and the OUT end, and a second linear voltage dividing resistor, a third linear voltage dividing resistor, a fourth linear voltage dividing resistor, a fifth linear voltage dividing resistor and a sixth linear voltage dividing resistor which are connected in series between the ADJ end and the grounding end, and are electrically connected with the first voltage dividing control end between the third linear voltage dividing resistor and the fourth linear voltage dividing resistor, and the second voltage dividing control end between the fifth linear voltage dividing resistor and the sixth linear voltage dividing resistor; when the IN end of the linear power supply chip is connected with 15V, the first voltage division control end and the second voltage division control end are suspended, and the OUT end outputs 12V voltage; when the IN terminal of the linear power supply chip is connected with 6.6V, the first voltage division control terminal is suspended, the second voltage division control terminal is grounded, and the OUT terminal outputs 5V voltage; when the IN terminal of the linear power supply chip is connected with 4.8V, the first voltage division control terminal is grounded, the second voltage division control terminal is suspended, and the OUT terminal outputs 3.3V voltage.
In another embodiment of the test substrate suitable for multiple specifications of crystal oscillators, the second test socket comprises a source signal access end and a corresponding grounding end, and the source signal access end is electrically connected with or grounded to a signal output pin of the crystal oscillator to be tested, which is inserted into the test plugboard, through a second test pin group corresponding to the test plugboard; the power supply test circuit further comprises a buffer output module for buffering source signals output by the crystal oscillator to be tested, the buffer output module comprises a chip BUF602ID and a voltage stabilizing chip 78L10, the input end of the voltage stabilizing chip 78L10 is electrically connected with the output end of the power supply filter chip BNX025H01L, the output end of the voltage stabilizing chip 78L10 inputs 10V direct current voltage to the power supply end of the chip BUF602ID, the negative power supply end of the chip BUF602ID is grounded, the source signal access end is connected with the signal output pin of the crystal oscillator to be tested through a direct current blocking capacitor, and the signal output end outputs the crystal oscillator output signals subjected to buffer processing through a resistor and a capacitor which are connected in series.
In another embodiment of the test substrate suitable for multiple specifications of crystal oscillators, the second test socket further comprises a crystal oscillator voltage end electrically connected with the OUT end of the linear power supply chip LM1085 and used for supplying power to the crystal oscillator to be tested, and the crystal oscillator voltage end is electrically connected with the power supply end of the crystal oscillator to be tested through a corresponding second test pin group on the test plug board; the first test socket further comprises a 12V voltage end, a 5V voltage end and a 3.3V voltage end, the three voltage ends are respectively grounded through a voltage indication light emitting diode and a current limiting resistor which are connected in series, and the 12V voltage end, the 5V voltage end or the 3.3V voltage end is electrically connected with the crystal oscillator voltage end through a corresponding first test pin group on the test plug board, so that the corresponding voltage indication light emitting diode is lightened.
The beneficial effects of the invention are as follows: the invention discloses a test substrate suitable for crystal oscillators of various specifications, which comprises a power supply socket, an output socket for outputting source signals of the crystal oscillator to be tested, a test socket correspondingly and electrically connected with a test plug of a test plug board, and a test circuit arranged on the back of the test substrate. The test sockets are respectively corresponding to three test pin groups of the test substrate, a plurality of wiring terminals in the test sockets are electrically connected with input and output ends and control ends of a plurality of modules in the test circuit, and the connection control relation of the wiring terminals in the test circuit can be changed by corresponding connection with the test pin groups on the test plug board, so that the test plug board can adapt to test plug boards with different power supply types. The test substrate provides a unified power supply platform for the test plugboards with various power supply types, and is convenient for the power-up test of the crystal oscillators with various specifications.
Drawings
FIG. 1 is a schematic diagram showing the front composition of an embodiment of a test substrate suitable for use with various specifications of crystal oscillators;
FIG. 2 is a schematic view of the back side composition of the embodiment of FIG. 1;
FIG. 3 is a schematic diagram of a first test socket terminal for one embodiment of a test substrate for a plurality of specifications of crystal oscillators according to the present invention;
FIG. 4 is a schematic diagram showing a power filter module circuit of an embodiment of a test substrate for a plurality of specifications of crystal oscillators according to the present invention;
FIG. 5 is a schematic diagram of a third test socket terminal for one embodiment of a test substrate for a multi-specification crystal oscillator according to the present invention;
FIG. 6 is a schematic diagram of a switching power module and an LC tank circuit of an embodiment of a test substrate for a plurality of specifications of crystal oscillators according to the present invention;
FIG. 7 is a schematic diagram of a second test socket terminal for one embodiment of a test substrate for a plurality of specification crystal oscillators according to the present invention;
FIG. 8 is a schematic diagram illustrating a linear power module circuit configuration of a test substrate suitable for use with multiple specification crystal oscillators according to an embodiment of the present invention;
FIG. 9 is a schematic diagram showing a buffer output module circuit of an embodiment of a test substrate suitable for use with various specifications of crystal oscillators.
Detailed Description
In order that the invention may be readily understood, a more particular description thereof will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Fig. 1 and 2 are schematic diagrams illustrating an embodiment of a test substrate suitable for use with various specifications of crystal oscillators. As shown in fig. 1, the test substrate includes a power supply socket 11 disposed on the front surface of the test substrate 1 and used for accessing external dc voltage, an output socket 12 outputting a source signal of a crystal oscillator to be tested, a test socket 13 correspondingly electrically connected to a test socket of the test board, and a test circuit disposed on the back surface of the test substrate. Fig. 1 also shows a voltage indicating light emitting diode 20. As shown in fig. 2, the test circuit includes a power filter module 14, an external dc voltage is input to the power filter module 14 through a power switch 18 after passing through the power supply socket 11, and then two paths are output, wherein a first path is directly connected to a high voltage channel, a second path is connected to a low voltage channel through a switching power module 15 and an LC tank circuit 16 which are connected in series, and a linear power module 17, and an input end of the linear power module 17 selects an output end of the high voltage channel or an output end of the low voltage channel through a first test socket 131 described below. In addition, fig. 1 also shows a circular opening 21, and the circular opening 21 is used for accommodating a cylindrical cap, and the cap is used for covering the crystal oscillator under test, so as to ensure that the crystal oscillator is not disturbed by external environment during testing, for example, wind blowing is prevented, and the like.
Further, as shown in fig. 1, the test socket 13 includes a first test socket 131 having a double-row 12 jack, a second test socket 132 having a double-row 10 jack, and a third test socket 133 having a double-row 4 jack, and the test socket corresponds to a first test pin group including a double-row 12 pin, a second test pin group having a double-row 10 jack, and a third test pin group including a double-row 4 pin.
Further, as shown in fig. 2 and 3, the first test socket 131 includes a high voltage input terminal 1311 (including two side-by-side jacks) electrically connected to the output terminal of the high voltage channel; a low voltage input 1312 (comprising two side-by-side jacks) electrically connected to the output of the low voltage channel; a voltage common 1313 (comprising two side-by-side jacks) is electrically connected to the input of the connecting linear power module. As can be seen in fig. 3, this also facilitates selection of the voltage common 1313 from the high voltage input 1311 and the low voltage input 1312, such as by a jumper cap, due to the voltage common 1313 being interposed between these two inputs. Preferably, the high voltage input end and the voltage common end are electrically connected through a corresponding first test pin group on the test plugboard, or the low voltage input end and the voltage common end are electrically connected; and the linear power supply module carries out linear voltage division on the input voltage to obtain the power supply voltage of the crystal oscillator to be tested, which is inserted on the test plugboard.
It can be seen that, according to the embodiment of the invention, a common test circuit is provided on the test substrate, and the voltage output by the test circuit can be connected to different terminals of the test socket through the test socket, and then the corresponding connection relationship on the test sockets is determined according to the different connection relationships of the pin groups on the test plugboard corresponding to the test socket, so that different power supplies can be realized by only changing the electrical connection relationship of the pins on the test plugboard.
Further, the external dc voltage is 15V, as shown in fig. 4, the power filtering module includes a power filtering chip BNX025H01L, the output end of the power filtering chip is a dc voltage 15V after voltage stabilization filtering, the power input end B of the chip 101 is connected to the positive pole of the external dc voltage through a power switch SW1 (i.e. a power switch 18 corresponding to fig. 1), and 11D1 anti-reverse diodes are further disposed at two ends of the external dc voltage to prevent reverse connection of the voltage polarity of the external dc voltage. The light emitting diode 11D2 and the current limiting resistor 11R1 are further connected in series between the power input terminal B and the input ground terminal PSG, and when SW1 is closed, the light emitting diode 11D2 is turned on, which indicates that the external voltage has been connected. The output end CB after the module filtering outputs the direct current voltage after the voltage stabilizing filtering to the subsequent stage. The three output grounds CG are commonly grounded.
As shown in fig. 5, the 4 jacks of the third test socket include a switching power supply control end 1331 and a corresponding ground end 1333, a low voltage selection end 1332 and a corresponding ground end 1333, and the switching power supply control end 1331 is suspended or grounded and the low voltage selection end 1332 is suspended or grounded through a corresponding third test pin group on the test socket.
Preferably, the switching power supply module comprises a chip TPS54327. As shown in fig. 6, the VIN end of the chip 102 is electrically connected to the HV end shown in fig. 4, the end is further grounded through a polar capacitor 12E1 and a non-polar capacitor 12C1, the SS end is grounded through a capacitor 12C2, the VREGS end is grounded through a capacitor 12C3, the CG end is directly grounded, the VBST end is electrically connected to the SW end through a capacitor 12C4, the SW end is connected in series with a first output inductor 12L1, the other end of the first output inductor 12L1 outputs a switching power supply output voltage, which is the output voltage of the switching power supply module 15, and it can be seen that the switching power supply output voltage is regulated and controlled by a voltage division RC network, i.e., an RC network formed from a fourth voltage division resistor 12R2 to a first voltage division resistor 12R5 and a first voltage division capacitor 12C 5.
In addition, the EN terminal of the chip 102 is directly connected to the switch power control terminal SWEN, and is electrically connected to the VIN terminal through the first enabling resistor 12R 1. When the switch power control terminal SWEN is suspended, the EN terminal can obtain the enable signal through the first enable resistor 12R1 to operate, and when the switch power control terminal SWEN is grounded, the chip 102 will not operate any more.
Further, the voltage dividing RC network includes a first voltage dividing resistor 12R5 connected to the output voltage of the switching power supply, the other end of the first voltage dividing resistor 12R5 is connected to the VFB end of the switching power supply chip TPS54327, the two ends of the first voltage dividing resistor 12R5 are connected in parallel to a first voltage dividing capacitor 12C5, the VFB end is grounded through a second voltage dividing resistor 12R4, a third voltage dividing resistor 12R3 and a fourth voltage dividing resistor 12R2 which are sequentially connected in series, a low voltage selection end SWVIG is further connected between the third voltage dividing resistor 12R3 and the fourth voltage dividing resistor 12R2, and when the output voltage of the power supply filter chip BNX025H01L is 15V, the output voltage of the switching power supply is 6.6V when the low voltage selection end SWVIG is grounded, the calculating method of the output voltage of the switching power supply is as follows: vout=0.765× (1+12r5/(12r3+12r4)). When the low-voltage selection end SWVIG is suspended, the output voltage of the switching power supply is 4.8V. The method for calculating the output voltage of the switching power supply comprises the following steps: vout=0.765× (1+12r5/(12r2+12r3+12r4)).
Preferably, the voltage dividing resistor 12 r5=143 kΩ,12 r4=18 kΩ,12 r3=510 Ω,12 r2=8.2 kΩ. It is clear that vout=0.765× (1+143/(18+0.51))=6.675V, approximately 6.6V above and within error when SWVIG is grounded, and vout=0.765× (1+143/(18+0.51+8.2))=4.86V, approximately 4.8V above and within error when SWVIG is suspended.
Therefore, the switching power supply module can be seen as a low-voltage channel, on one hand, whether the module has voltage output can be controlled through the switching power supply control end SWEN, and on the other hand, the specific output voltage value of the module can be controlled through the low-voltage selection end SWVIG, so that the next-stage linear power supply module can be beneficial to pointedly selecting proper power supply voltage to crystal oscillators with different specifications, and on the other hand, the switching power supply module has the problems of saving energy consumption, reducing power supply loss, heating and the like.
Further, in fig. 6, the output voltage of the switching power supply output by the first output inductor 12L1 is input to the LC tank circuit, the LC tank circuit includes 4 parallel non-polar capacitors 13C1 to 13C4, and an energy storage inductor 13L1 electrically connected to the first output inductor 12L1, one ends of the non-polar capacitors 13C1 to 13C4 are electrically connected to the first output inductor 12L1 and the energy storage inductor 13L1, the other ends of the non-polar capacitors 13C1 to 13C4 are grounded, two ends of the energy storage inductor 13L1 are electrically connected to anodes of the 2 polar capacitors 13E1 and 13E2, and cathodes of the polar capacitors 13E1 and 13E2 are grounded. The LC tank circuit corresponds to the LC tank circuit 16 in fig. 2, and mainly stores a power supply signal output by the switching power supply module 15, so as to ensure stability of a power supply voltage of a subsequent stage and prevent power supply from being suddenly interrupted after power failure, and perform power supply protection on the subsequent stage.
After the switching power supply chip TPS54327 is turned on, the output voltage can be effectively regulated through the LC energy storage circuit, the on-off ratio (duty ratio) of output is regulated mainly through a switching tube which is rapidly turned on and off in the switching power supply chip TPS54327, for example, after the switching tube in the switching power supply chip TPS54327 is turned on, power is supplied to a first output inductor 12L1 and an energy storage inductor 13L1 to a subsequent stage load, and meanwhile the energy storage inductor 13L1 is charged, the energy storage inductor 13L1 is equivalent to a constant current source, a rapid energy transmission effect is achieved, the polarity capacitor 13E2 is equivalent to a constant voltage source, a filtering effect is achieved in the circuit, and after the switching tube in the switching power supply chip TPS54327 is turned off, the energy stored in the energy storage inductor 13L1 forms a loop through the polarity capacitor 13E1, and the power is continuously supplied to the subsequent stage load, so that continuous current of the load is ensured.
Further, as shown in fig. 7, the second test socket includes a linear power enable terminal 1321 and a corresponding ground terminal 1324, a first voltage division control terminal 1322 and a corresponding ground terminal 1324, a second voltage division control terminal 1323 and a corresponding ground terminal 1324, the linear power enable terminal 1321 is suspended or grounded, the first voltage division control terminal 1321 is suspended or grounded, and the second voltage division control terminal 1321 is suspended or grounded through a third test pin group corresponding to the test board.
Preferably, the linear power supply includes a chip LM1085. As shown IN fig. 8, the IN terminal of the linear power chip is electrically connected to the voltage common terminal 1313 of the first test socket of fig. 3, denoted herein as MV terminal. The MV terminal is an input terminal, and when the MV terminal is electrically connected with the high voltage input terminal in FIG. 1, the MV terminal is connected with the high voltage output by the HV terminal in FIG. 4, for example, 15V; when the MV terminal is electrically connected to the low voltage input terminal of fig. 1, the MV terminal is connected to the low voltage output from the LV terminal shown in fig. 6, for example, 6.6V or 4.8V.
The collector of a triode 15Q1 is connected to the ADJ end, triode 15Q 1's projecting pole ground connection, first enable resistance 15R2 is connected to the base, and second enable resistance 15R1 is connected to the other end of first enable resistance 15R2, and the other end of second enable resistance 15R1 also is connected with the common output MV end electricity of first test socket be connected with linear power enable end LVEN end between first enable resistance and the second enable resistance.
When the linear power supply enabling terminal LVEN is suspended, the triode 15Q1 is conducted, the ADJ of the chip LM1085 is grounded, and the corresponding OUT terminal is output by reference voltage; when the linear power supply enable terminal LVEN is grounded, the triode 15Q1 is turned off, the ADJ terminal of the chip LM1085 is not grounded, and the corresponding OUT terminal outputs the voltage division value of the controllable resistance network.
The controllable resistance network comprises a first linear voltage-dividing resistor 15R3 between the ADJ end and the OUT end, a second linear voltage-dividing resistor 15R4, a third linear voltage-dividing resistor 15R5, a fourth linear voltage-dividing resistor 15R6, a fifth linear voltage-dividing resistor 15R7 and a sixth linear voltage-dividing resistor 15R8 which are connected in series between the ADJ end and the ground end, a first voltage-dividing control end LVO3 is arranged between the third linear voltage-dividing resistor 15R5 and the fourth linear voltage-dividing resistor 15R6, and a second voltage-dividing control end LVO5 is arranged between the fifth linear voltage-dividing resistor 15R7 and the sixth linear voltage-dividing resistor 15R 8;
when the IN terminal of the linear power supply chip is connected to 15V, the first voltage division control terminal LVO3 and the second voltage division control terminal LVO5 are suspended, the OUT terminal outputs 12V voltage, and the method for calculating the output voltage of the OUT terminal is as follows: vlout=1.25× (1+ (15r4+15r5+15r6+15r7+15r8)/15R 3); when the IN end of the linear power supply chip is connected with 6.6V, the first voltage division control end LVO3 is suspended, the second voltage division control end LVO5 is grounded, the OUT end outputs 5V voltage, and the method for calculating the output voltage of the OUT end is as follows: vlout=1.25× (1+ (15r4+15r5+15r6+15r7)/15R 3); when the IN end of the linear power supply chip is connected with 4.8V, the first voltage division control end LVO3 is grounded, the second voltage division control end LVO5 is suspended, the OUT end outputs 3.3V voltage, and the method for calculating the output voltage of the OUT end is as follows: vlout=1.25× (1+ (15r4+15r5)/15R 3). It should be noted that, the method of calculating the output voltage at the OUT terminal has no direct relation with the input voltage, and is actually used as a linear power supply chip, which is mainly to divide the input voltage by resistors to obtain the output voltage, and if the voltage division ratio of the output voltage with respect to the input voltage is smaller, there is a larger loss, for example, the voltage division ratio of 3.3V with respect to the input 15V is significantly smaller than the voltage division ratio of 3.3V with respect to the input 4.8V. In order to improve the power supply efficiency of the power supply, the corresponding 6.6V and 4.8V are obtained through the switching power supply module and then the corresponding 5V and 3.3V are obtained through the linear power supply module for 5V and 3.3V respectively, and the switching power supply module has higher efficiency, and the linear power supply module can also obtain higher voltage division ratio, so that the overall efficiency is high. In addition, the linear power supply module has better ripple characteristics, so that a power supply for directly supplying power to the crystal oscillator is a linear power supply module instead of a switching power supply module, and the linear power supply module is also used for ensuring the stability of the power supply voltage of the crystal oscillator and obtaining more accurate measurement conditions.
Further, 15 r3=100deg.C, 15 r4=82Ω,15 r5=82Ω,15 r6=100deg.C, 15 r7=36Ω,15 r8=560 Ω. The output voltages of the OUT terminal are 12V, 5V and 3.3V respectively.
Further, as shown in fig. 7, the second test socket includes a source signal access terminal 1325 and a corresponding grounding terminal 1324, and the source signal access terminal is electrically connected to or grounded to a signal output pin of the crystal oscillator to be tested plugged on the test plug board through the second test pin group corresponding to the test plug board.
As shown in fig. 1, the power supply test circuit further includes a buffer output module 19 for buffering a source signal output by the crystal oscillator to be tested, where the buffer output module includes a chip BUF602ID and a voltage stabilizing chip 78L10, an input end of the voltage stabilizing chip 78L10 is electrically connected to an output end of the power supply filter chip BNX025H01L, an output end of the voltage stabilizing chip 78L10 inputs a 10V dc voltage to a power supply end of the chip BUF602ID, and as shown in fig. 9, a power supply end VCC of the chip BUF602ID is connected to 10V, and the 10V voltage is a stable 10V voltage output after the HV end of the power supply filter module is electrically connected to the voltage stabilizing chip 78L 10. The negative power end-VCC is directly grounded, the signal input end IN is connected to a source signal S20 from the crystal oscillator to be tested through a DC blocking capacitor C161, and the output end OUT outputs a crystal oscillator output signal S21 subjected to buffer treatment through a resistor R161 and a capacitor C164 which are connected IN series.
The buffer output module can be used for carrying out interface matching and isolation for the subsequent stage, so that the reliability of the test is ensured. Specifically, because the crystal oscillator has the characteristic of load adjustment rate, namely the load connection and disconnection of the output signal of the test crystal oscillator can influence the output frequency of the test crystal oscillator, in order to ensure the stability or consistency of the output frequency, a matched load is correspondingly added through the buffer output module, and the matched load also has the characteristics of high-resistance input and low-resistance output, and is convenient to connect with the subsequent stage. In addition, after the buffer output module is arranged, the output frequency of the crystal oscillator is not affected no matter the rear load is connected or the rear load is not connected, so that the risk of change of the output frequency of the crystal oscillator caused by load change is avoided.
Further, as shown in fig. 7, the second test socket further includes a crystal oscillator voltage terminal 1326 electrically connected to the OUT terminal of the linear power chip LM1085 and supplying power to the crystal oscillator to be tested, and the crystal oscillator voltage terminal 1326 is electrically connected to the power supply terminal of the crystal oscillator to be tested through a corresponding second test pin group on the test board.
Further, the first test socket further includes a 12V voltage terminal 1314, a 5V voltage terminal 1315, and a 3.3V voltage terminal 1316, where the three voltage terminals are respectively grounded through a voltage indicating light emitting diode (e.g., a voltage indicating light emitting diode 20 shown in fig. 1) and a current limiting resistor connected in series, and the 12V voltage terminal, the 5V voltage terminal, or the 3.3V voltage terminal is electrically connected to the crystal oscillator voltage terminal through a corresponding first test pin group on the test socket board, so that the corresponding voltage indicating light emitting diode is turned on.
The invention discloses a test substrate suitable for crystal oscillators of various specifications, which comprises a power supply socket, an output socket for outputting source signals of the crystal oscillator to be tested, a test socket correspondingly and electrically connected with a test plug of a test plug board, and a test circuit arranged on the back of the test substrate. The test sockets are respectively corresponding to three test pin groups of the test substrate, a plurality of wiring terminals in the test sockets are electrically connected with input and output ends and control ends of a plurality of modules in the test circuit, and the connection control relation of the wiring terminals in the test circuit can be changed by corresponding connection with the test pin groups on the test plug board, so that the test plug board can adapt to test plug boards with different power supply types. The test substrate provides a unified power supply platform for the test plugboards with various power supply types, and is convenient for the power-up test of the crystal oscillators with various specifications.
The foregoing description is only illustrative of the present invention and is not intended to limit the scope of the invention, and all equivalent structural changes made by the present invention and the accompanying drawings, or direct or indirect application in other related technical fields, are included in the scope of the present invention.
Claims (6)
1. The test substrate is characterized by comprising a power supply socket, an output socket, a test socket and a test circuit, wherein the power supply socket is arranged on the front surface of the test substrate and used for being connected with external direct-current voltage, the output socket is used for outputting source signals of a crystal oscillator to be tested, the test socket is electrically connected with a test plug pair of a test plug board, and the test circuit is arranged on the back surface of the test substrate;
the test circuit comprises a power supply filter module, wherein external direct-current voltage is output into two paths after passing through the power supply filter module, the first path is directly connected as a high-voltage channel, and the second path is connected in series through a switching power supply module and an LC energy storage circuit as a low-voltage channel;
the test socket comprises a first test socket with double-row 12 jacks, a second test socket with double-row 10 jacks and a third test socket with double-row 4 jacks, and the test plug board corresponds to a first test pin group with double-row 12 pins, a second test pin group with double-row 10 pins and a third test pin group with double-row 4 pins;
the first test socket comprises a high-voltage input end and is electrically connected with the output end of the high-voltage channel; the low-voltage input end is electrically connected with the output end of the low-voltage channel; the voltage common end is electrically connected with the input end of the linear power supply module; the high voltage input end is electrically connected with the voltage common end through a first corresponding test pin group on the test plugboard, or the low voltage input end is electrically connected with the voltage common end; the linear power module performs linear voltage division on the input voltage to obtain the power supply voltage of the crystal oscillator to be tested, which is inserted on the test plugboard;
the external direct-current voltage is 15V, the power supply filtering module comprises a power supply filtering chip BNX025H01L, the output end of the power supply filtering chip is the direct-current voltage 15V subjected to voltage stabilization filtering, the power supply input end of the power supply filtering chip is connected with the positive electrode of the external direct-current voltage through a power supply switch, anti-reverse diodes are further arranged at the two ends of the external direct-current voltage, a light emitting diode and a current limiting resistor are further connected in series between the power supply input end and an input grounding end, when the power supply switch is closed, the light emitting diode is lighted to indicate that the external direct-current voltage is connected, and the output end of the power supply filtering chip outputs the filtered direct-current voltage to the next stage, and the three output grounding ends are grounded together;
the 4 jacks of the third test socket comprise a switch power supply control end and a corresponding grounding end, the low-voltage selection end and the corresponding grounding end, the switch power supply control end is suspended or grounded through a corresponding third test pin group on the test plug board, and the low-voltage selection end is suspended or grounded.
2. The test substrate suitable for multiple specifications of crystal oscillators according to claim 1, wherein the switching power supply module comprises a switching power supply chip TPS54327, wherein a VIN end of the switching power supply chip is electrically connected with an output end of the power supply filter chip BNX025H01L, an EN end is electrically connected with the switching power supply control end on one hand, and is also electrically connected with the VIN end through a first enabling resistor on the other hand, when the switching power supply control end is suspended, the EN end obtains an enabling signal through the first enabling resistor so that the switching power supply chip TPS54327 works, and when the switching power supply control end is electrically connected with a corresponding grounding end, the switching power supply chip TPS54327 does not work;
the VBST end of the switch power supply chip TPS54327 is electrically connected with the SW end through a capacitor, the SW end is connected with a first output inductor in series, and the other end of the first output inductor outputs the output voltage of the switch power supply;
the output voltage of the switching power supply is regulated and controlled by a voltage division RC network, the voltage division RC network comprises a first voltage division resistor connected with the output voltage of the switching power supply, the other end of the first voltage division resistor is connected with a VFB end of a TPS54327 of the switching power supply, the two ends of the first voltage division resistor are connected with a first voltage division capacitor in parallel, the VFB end is grounded through a second voltage division resistor, a third voltage division resistor and a fourth voltage division resistor which are sequentially connected in series, the third voltage division resistor and the fourth voltage division resistor are electrically connected with a low-voltage selection end, when the output voltage of a BNX025H01L of the power supply filter chip is 15V, the output voltage of the switching power supply is 6.6V when the low-voltage selection end is grounded, and when the low-voltage selection end is suspended, the output voltage of the switching power supply is 4.8V.
3. The test substrate applicable to multiple specifications of crystal oscillators according to claim 2, wherein the output voltage of the switching power supply output by the first output inductor is input to the LC tank circuit, the LC tank circuit comprises 4 parallel non-polar capacitors and an energy storage inductor electrically connected with the first output inductor, one end of each non-polar capacitor is electrically connected with the first output inductor and the energy storage inductor, the other end of each non-polar capacitor is grounded, two ends of each energy storage inductor are respectively electrically connected with anodes of 2 polar capacitors, and cathodes of the polar capacitors are grounded.
4. The test substrate for multiple specification crystal oscillator according to claim 3, wherein the second test socket comprises a linear power supply enabling end and a corresponding grounding end, a first voltage division control end and a corresponding grounding end, a second voltage division control end and a corresponding grounding end, the linear power supply enabling end is suspended or grounded through a second test pin group corresponding to the test plug board, the first voltage division control end is suspended or grounded, and the second voltage division control end is suspended or grounded;
the linear power supply module comprises a linear power supply chip LM1085, wherein the IN end of the linear power supply chip is electrically connected with the voltage common end of the first test socket, the ADJ end is connected with a collector electrode of a triode, an emitter electrode of the triode is grounded, the base electrode is connected with a first enabling resistor, the other end of the first enabling resistor is connected with a second enabling resistor, the other end of the second enabling resistor is also electrically connected with the voltage common end of the first test socket, and the first enabling resistor and the second enabling resistor are electrically connected with the linear power supply enabling end;
when the linear power supply enabling end is suspended, the triode is conducted, the ADJ end of the chip LM1085 is grounded, and the corresponding OUT end is output by reference voltage; when the linear power supply enabling end is grounded, the triode is cut off, the ADJ end of the chip LM1085 is not grounded, and the corresponding OUT end outputs the voltage division value of the controllable resistor network;
the controllable resistance network comprises a first linear voltage dividing resistor between the ADJ end and the OUT end, and a second linear voltage dividing resistor, a third linear voltage dividing resistor, a fourth linear voltage dividing resistor, a fifth linear voltage dividing resistor and a sixth linear voltage dividing resistor which are connected in series between the ADJ end and the grounding end, and are electrically connected with the first voltage dividing control end between the third linear voltage dividing resistor and the fourth linear voltage dividing resistor, and the second voltage dividing control end between the fifth linear voltage dividing resistor and the sixth linear voltage dividing resistor;
when the IN end of the linear power supply chip is connected with 15V, the first voltage division control end and the second voltage division control end are suspended, and the OUT end outputs 12V voltage; when the IN terminal of the linear power supply chip is connected with 6.6V, the first voltage division control terminal is suspended, the second voltage division control terminal is grounded, and the OUT terminal outputs 5V voltage; when the IN terminal of the linear power supply chip is connected with 4.8V, the first voltage division control terminal is grounded, the second voltage division control terminal is suspended, and the OUT terminal outputs 3.3V voltage.
5. The test substrate suitable for multiple crystal oscillators according to claim 4, wherein the second test socket comprises a source signal access end and a corresponding grounding end, and the source signal access end is electrically connected with or grounded to a signal output pin of a crystal oscillator to be tested, which is plugged into the test plug board, through a second test pin group corresponding to the test plug board;
the test circuit further comprises a buffer output module for buffering source signals output by the crystal oscillator to be tested, the buffer output module comprises a chip BUF602ID and a voltage stabilizing chip 78L10, the input end of the voltage stabilizing chip 78L10 is electrically connected with the output end of the power filtering chip BNX025H01L, the output end of the voltage stabilizing chip 78L10 inputs 10V direct current voltage to the power end of the chip BUF602ID, the negative power end of the chip BUF602ID is grounded, the source signal access end is connected with a signal output pin of the crystal oscillator to be tested through a direct current blocking capacitor, and the signal output end outputs the crystal oscillator output signals subjected to buffer treatment through a resistor and a capacitor which are connected in series.
6. The test substrate suitable for multiple specifications of crystal oscillators according to claim 5, wherein the second test socket further comprises a crystal oscillator voltage terminal electrically connected with an OUT terminal of the linear power supply chip LM1085 and supplying power to the crystal oscillator to be tested, and the crystal oscillator voltage terminal is electrically connected with a power supply terminal of the crystal oscillator to be tested through a corresponding second test pin group on the test board;
the first test socket further comprises a 12V voltage end, a 5V voltage end and a 3.3V voltage end, the three voltage ends are respectively grounded through a voltage indication light emitting diode and a current limiting resistor which are connected in series, and the 12V voltage end, the 5V voltage end or the 3.3V voltage end is electrically connected with the crystal oscillator voltage end through a corresponding first test pin group on the test plug board, so that the corresponding voltage indication light emitting diode is lightened.
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