CN214335032U

CN214335032U - Program-controlled composite voltage current source circuit

Info

Publication number: CN214335032U
Application number: CN202120201579.3U
Authority: CN
Inventors: 王煜
Original assignee: Shaanxi Sanhai Test Technology Development Co ltd
Current assignee: Saiyinte Semiconductor Technology Xi'an Co ltd
Priority date: 2021-01-25
Filing date: 2021-01-25
Publication date: 2021-10-01
Anticipated expiration: 2031-01-25

Abstract

A program-controlled composite voltage current source circuit comprises a plurality of VI driving branches and two voltage differential sampling branches, wherein the VI driving branches are arranged in parallel, and each VI driving branch comprises a voltage gear selector switch and a current gear selector switch; each VI driving branch can be constructed as a standard VI source, current sampling is realized through a current gear selector switch, and voltage sampling of the voltage differential sampling branch correspondingly acquires differential voltage between the voltage at the output end of each VI driving branch and two SGND points; different parameter test loops are realized by adjusting the voltage gear change-over switch and the current gear change-over switch. The utility model discloses can establish out a lot of brand-new test circuit, convenient to use can make the volume reduce by a wide margin simultaneously, makes the functional module integration of test semiconductor device direct current parameter have the feasibility on an integrated circuit board, has improved the integrated level, can test more devices in parallel.

Description

Program-controlled composite voltage current source circuit

Technical Field

The utility model belongs to semiconductor device test field, concretely relates to programme-controlled composite voltage current source circuit.

Background

The program-controlled voltage current source is also called as a VI source, and refers to a multifunctional power supply circuit which can be controlled by software, can output positive and negative voltages and currents, can also sample the voltages and the currents, and is characterized by being capable of freely outputting in a four-quadrant range. For example, the output voltage is set to be a positive voltage output, and the output voltage can be ensured and can be used as a power supply output current or an electronic load input current. Thus, the VI source can be viewed as a power source that tends to be idealized.

The VI source generally has an output line HF and a sampling line HS; there is also an output ground LF and an output ground sampling line LS. When the voltage source is set, the HS-LS equivalent to the set value is achieved through the internal closed loop circuit. In a semiconductor test device, the VI source is a common configuration, and can flexibly load and sample each pin of a device under test. However, in testing of certain semiconductor device parameters, relying solely on standard VI sources is not sufficient to build a complete test loop. Such as gfs (gmp) parametric testing of MOSFETs, hfe testing of BJTs, etc., additional test loops are required. Like the GMP test loop in fig. 1, LV2 is a current source (standard VI), LV3 is a varying current source (standard VI), and LV1 is a voltage source (non-standard VI). LV1 cannot be implemented with standard VI because its LF, LS are not connected to a fixed power ground, but instead are floating. Thus, to accomplish GMP testing, either a dedicated closed loop outside the VI is designed or a dedicated LF/LS floatable VI source is designed. This complicates testing the loop and also complicates testing other parameters.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to need additionally to build the problem in test circuit when the different parameters of VI source test among the above-mentioned prior art, provide a programme-controlled composite voltage current source circuit, the integrated level is higher, can satisfy the test of multiple parameter simultaneously.

In order to achieve the above object, the present invention provides the following technical solutions:

a program-controlled composite voltage current source circuit comprises a plurality of VI driving branches and two voltage differential sampling branches, wherein the VI driving branches are arranged in parallel, and each VI driving branch comprises a voltage gear selector switch and a current gear selector switch; each VI driving branch can be constructed as a standard VI source, current sampling is realized through a current gear selector switch, and voltage sampling of the voltage differential sampling branch correspondingly acquires differential voltage between the voltage at the output end of each VI driving branch and two SGND points; different parameter test loops are realized by adjusting the voltage gear change-over switch and the current gear change-over switch.

As an optimized scheme of the utility model, VI drive branch road set up A, B, C three in parallel, can be simultaneously parallel to measure same or different semiconductor device's three pin.

As an optimized scheme of the utility model, voltage gear change over switch and electric current gear change over switch between select to be connected through the function selector switch.

As an optimized scheme of the utility model, voltage gear change over switch include a plurality of parallelly connected switches, its quantity corresponds with VI drive branch road to and a earthing switch who connects SGND.

As a preferred scheme of the utility model, VI drive branch road all includes SENSE end and FORCE end, and current gear change over switch includes two switches that parallelly connected, and one of them is connected to the FORCE end, and another is connected to the SENSE end.

As an optimized scheme of the utility model, the voltage gear change over switch and the electric current gear change over switch of every VI drive branch road set up through the computer.

Compared with the prior art, the utility model discloses following beneficial effect has: when an independent VI source in the prior art is used for carrying out parameter test on a tested unit (DUT), different test loops are set up for the same tested unit according to actual measurement parameter projects, and meanwhile, the independent VI source can only measure one pin of the tested unit, so that the measurement steps of a plurality of pins are complex and tedious. The utility model discloses can construct out a lot of brand-new test circuit, every VI drive branch road homoenergetic can be constructed for the VI source of standard, just can accomplish the test such as parameter of hfe, gfs through this kind of circuit, and external loop is simple, convenient to use. Meanwhile, the whole volume can be greatly reduced, and the functional module for testing the direct current parameters of the semiconductor device is integrated on one board card, so that more board cards can be inserted into the testing equipment, the integration level is improved, and more devices can be tested in parallel.

Furthermore, in view of 3 effective pins at most of general semiconductor devices, the utility model discloses 3 integrated floating VI sources together of special design, through the switch switching, make the LF/LS that every VI source all can switch to on each pin in a flexible way. Therefore, various special test loops can be built through software, and special project tests which cannot be independently completed by the standard VI source can be completed.

Drawings

Fig. 1 is a schematic diagram of a conventional GMP test loop configuration;

fig. 2 is a schematic diagram of the circuit structure of the present invention;

figure 3 the utility model discloses carry out parameter setting's computer interface schematic diagram.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 2, the present invention includes a plurality of VI driving branches and two voltage differential sampling branches, which are arranged in parallel, each VI driving branch includes a voltage gear shift switch and a current gear shift switch; the voltage gear selector switch and the current gear selector switch are selectively connected through a function selector switch. Each VI driving branch can be constructed as a standard VI source, current sampling is realized through a current gear selector switch, each VI driving branch comprises a SENSE end and a FORCE end, the current gear selector switch comprises two switches connected in parallel, one of the two switches is connected to the FORCE end, and the other switch is connected to the SENSE end. The voltage sampling of the voltage differential sampling branch circuit correspondingly acquires the differential voltage between the voltage of the output end of each VI driving branch circuit and the two SGND points; different parameter test loops are realized by adjusting the voltage gear change-over switch and the current gear change-over switch. The voltage gear selector switch comprises a plurality of switches connected in parallel, the number of the switches corresponds to that of the VI driving branch circuits, and a grounding switch connected with the SGND. And the voltage gear change-over switch and the current gear change-over switch of each VI driving branch circuit are set through a computer. In view of the maximum 3 effective pins of a general semiconductor device, the VI driving branches of an embodiment of the present invention are arranged A, B, C in parallel, and can simultaneously measure three pins of the same or different semiconductor devices in parallel.

The utility model discloses a circuit includes 3 group VI source output circuit, and the homophase of the voltage feedback loop of every group, inverting terminal can all come from the sense line of 3 group's outputs. The voltage feedback switch is matched with the combination body, so that various closed loops with different combinations can be realized.

The utility model discloses a voltage sampling is independent of 3 group VI sources.

The utility model discloses a current loading is the same with standard VI source return circuit with the sampling.

The circuit structure shown in fig. 2 includes A, B, C three VI driving loops and 2 voltage differential sampling loops.

With path a for example, SETA set, R2A switches to VSHIFT; K1A closed with K8A; K9A closed with K12A; this constitutes a standard VI source output voltage loop. VSHIFT is voltage gear switching, ISHIFT is current gear switching, SENSE _ A is output end voltage sampling, and FORCE _ A is an output end. As above, switch R2A to ISHIFT; K9A closed with K12A; this constitutes the output current loop of a standard VI source.

A. B, C three ways can be constructed as standard VI sources. Its current MI _ A, MI _ B, MI _ C samples are from the respective ISHIFT. The voltage samples MV _1 and MV _2 correspond to a differential voltage between any two points SENSE _ A, SENSE _ B, SENSE _ C, SGND. Under general use requirements, A, B, C three ways can be configured for standard VI source use.

The utility model discloses a special function that can realize to A way example: SETA is set current, R2A switches to ISHIFT; K10A closed with K12A; K14A is closed. A contact self-test loop is formed. The contact resistance can be calculated by testing the voltage drop from SENSE _ a to FORCE _ a at MV _1 by closing K1D, K8D.

The utility model discloses another kind of special function that can realize, test N _ MOSFET's GMP parameter: the A circuit is connected with the GATE of the MOSFET and the standard VI loop, and is loaded with 0V voltage. The C circuit is connected with the SOURCE of the MOSFET and the standard VI circuit and is loaded with negative current. The B circuit connects the DRAIN of the MOSFET, and is a special VI loop, voltage mode, and closes K2B and K7B, and the voltage drop between SENSE _ B and SENSE _ C is used as voltage feedback. K1D and K7D are closed and MV _1 samples the Vgs voltage. GMP (gfs) can be calculated by sampling the change in Vgs with a change of plus or minus 5% in the C-path current.

In the circuit structure, A, B, C passes through various combinations in three ways, and various complex loops can be tested.

Referring to fig. 3, it is a parameter configuration interface of 3 groups of low voltage VI sources and 1 group of high voltage VI sources, except the lower left corner in the configuration diagram, the high voltage VI source and the related circuit are provided, the upper left corner in the diagram is a parameter setting interface, when in use, the parameter items are newly established, the test circuit can be set in each test parameter item through switch switching, the three triangles on the right side are voltage current sources (VI sources), voltage step setting can be performed in VSHIFT, and the voltage step setting can be used as a measurement range in the test circuit, and the same is true for isfft. The VI source can supply voltage and current to the loop and can also measure the voltage and the current in the loop, but the same VI source cannot measure the voltage while applying the voltage, and the pressurization and the pressure measurement are separated more accurately. Namely, pressurization and flow measurement, and pressurization and flow measurement. The end with lower pressure drop in the loop of the parameter test is pressurized and added with flow, and the end with higher pressure drop is tested with flow and pressure, so that the stability of the loop can be ensured, the impedance is lower, and the interference is not easy to cause.

Current measurement: if a leakage at the level of 30nA is tested, the current gear needs to be set to 0.2uA or 2 uA. If the leakage level is 4uA, the leakage level may be amplified to 20uA or 0.2 mA. Voltage loading: if-20V is loaded, the voltage gear needs to be larger than-20V, and the gear of 26.4V is selected. The current gear can be selected to be 2mA or 20 mA.

SET1 is to select loading voltage and current through the gear of UNIT, UNIT has two gears of MA and V, MA is loading current, V is loading voltage, PRE _ SET is a preset value, i.e. a preset value to be reached before starting measurement, if parameters of transient change such as breakdown voltage, amplification factor (hfe) and the like are to be measured, the preset value is 0, and the preset value is SET in 1ST _ SET. And the on-off of the circuit is controlled by the switch K to form a test loop, and the AS and the AF are connected with the sensor end and the force end of the tested device.

When the independent VI source among the prior art carries out parameter test to the unit under test (DUT), will set up different test circuit according to actual measurement parameter project to same unit under test, independent VI source can only measure a pin of unit under test simultaneously, and a plurality of pin measurement steps are complicated loaded down with trivial details, and the utility model discloses parallelly connected 3 VI sources of group can be measured 3 pins, and the computational formula of accessible measurement parameter calculates the mode of setting up of test circuit between 3 pins simultaneously, vice versa. The 3 groups of VI sources are mutually independent, and the built test loops can be realized without mutual interference through a switch circuit. It can also be inferred that multiple groups of VI sources are designed to measure multiple pins of the same device in parallel, or to measure multiple devices (with fewer pins) in parallel.

The above-described preferred embodiments of the present invention are not intended to limit the present invention, and it should be understood by those skilled in the art that the present invention can be modified and replaced by other simple modifications and replacements without departing from the spirit and principle of the present invention, and these modifications and replacements also fall within the protection scope of the appended claims.

Claims

1. A program-controlled composite voltage current source circuit is characterized in that: the voltage differential sampling circuit comprises a plurality of VI driving branches and two voltage differential sampling branches, wherein the VI driving branches are arranged in parallel, and each VI driving branch comprises a voltage gear selector switch and a current gear selector switch; each VI driving branch can be constructed as a standard VI source, current sampling is realized through a current gear selector switch, and voltage sampling of the voltage differential sampling branch correspondingly acquires differential voltage between the voltage at the output end of each VI driving branch and two SGND points; different parameter test loops are realized by adjusting the voltage gear change-over switch and the current gear change-over switch.

2. The programmable composite voltage and current source circuit of claim 1, wherein: the VI driving branches are arranged in parallel at A, B, C, and can simultaneously and in parallel measure three pins of the same or different semiconductor devices.

3. The programmable composite voltage and current source circuit of claim 1, wherein: the voltage gear selector switch is selectively connected with the current gear selector switch through a function selector switch.

4. The programmable composite voltage and current source circuit of claim 1, wherein: the voltage gear selector switch comprises a plurality of switches connected in parallel, the number of the switches corresponds to that of the VI driving branch circuits, and a grounding switch connected with the SGND.

5. The programmable composite voltage and current source circuit of claim 1, wherein: the VI driving branches comprise a SENSE end and a FORCE end, and the current gear change-over switch comprises two switches connected in parallel, wherein one switch is connected to the FORCE end, and the other switch is connected to the SENSE end.

6. The programmable composite voltage and current source circuit of claim 1, wherein: and the voltage gear change-over switch and the current gear change-over switch of each VI driving branch circuit are set through a computer.