CN201113972Y - Level switching circuit - Google Patents
Level switching circuit Download PDFInfo
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- CN201113972Y CN201113972Y CNU2007201727127U CN200720172712U CN201113972Y CN 201113972 Y CN201113972 Y CN 201113972Y CN U2007201727127 U CNU2007201727127 U CN U2007201727127U CN 200720172712 U CN200720172712 U CN 200720172712U CN 201113972 Y CN201113972 Y CN 201113972Y
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Abstract
The utility model provides a level switch circuit, which is used for realizing level switch between a RS232 level and a TTL level. The utility model comprises a common-emitter switching circuit which is formed by NPN switching tubes and connected in series between a RS232 level transmitting end and a TTL level receiving end, and a common-emitter switching circuit which is formed by PNP switching tubes and connected in series between a RS232 level receiving end and a TTL level transmitting end. Due to adoption of a medium and low power triode transistor, a medium and low power resistor and a medium and low power capacitor, the level switch circuit is low in cost and reliable in performance and can meet the requirements of debugging and application of consumer electronics such as set-top boxes and so on; under the condition of mass production, RMB 2.1 per set is saved averagely, thereby the economic benefit brought to enterprises is very considerable.
Description
Technical field
The utility model relates to level shifting circuit, is specifically related to a kind of level shifting circuit that is used to realize between RS232 level and the Transistor-Transistor Logic level.
Background technology
At present, ripe and popularization along with electronic technology, the debugging of many consumer electronics products with use in all can use consumer electronics product the serial port that mainboard provided be connected with the serial port of computer, carry out the transmission of data or the transmission and the reception of control command.
RS232 is a kind of serial physical interface standard that the EIA of EIA (Electronic Industry Association) formulates, and the voltage of any signal line is the negative logic relation in the RS232 standard, promptly logic " 1 " be-15V～-5V; Logic " 0 " is+5V～+ 15V, its noise margin is 2V, that is to say to require receiver to discern to be low to moderate+signal of 3V is as logic " 0 ", high signal to-3V is as logic " 1 ".
In the PC computer because of used chip or circuit difference, the RS232 level usually ± 9V～± 12V between.The connector of RS232 has the DB25 needle connector of standard and the DB9 pin type connector of simplification, and the serial ports that the mainboard of general consumer electronics product provides is to use transistor-transistor logic (Transistor-Transistor-Logic) Transistor-Transistor Logic level standard, standard TTL input high level＞=2.0V, input low level＜=0.8V, noise margin is 0.4V, output high level＞2.4V, output low level＜0.4V.At room temperature, logical one is 3.5V, and logical zero is 0.2V, adopt positive logic, the computer serial port is employed to be the level standard of RS232, and the logical one level of RS232 is-12V--3V, the logical zero level is+3V～+ 12V, employing be negative logic.Both level logics are opposite, noise margin is also inequality, can not discern mutually, therefore just need a kind of signal potential conversion equipment to allow to support the equipment and the communication between devices that utilizes TTL logical signal current potential of RS232 standard, in general business-like finished product can be used MAX232, the RS232 that DS275 etc. are special-purpose, the Transistor-Transistor Logic level converter ic, when a TTL signal is sent to the current potential conversion chip from the equipment that utilizes TTL logical signal current potential, the RS232 signal that the current potential conversion chip just can be discerned this conversion of signals for the equipment of supporting the RS232 standard is resent to the equipment of supporting the RS232 standard.In like manner, when a RS232 signal is sent to the current potential conversion chip from the equipment that utilizes RS232 logical signal current potential, the TTL signal that the current potential conversion chip just can be discerned this conversion of signals for the equipment of supporting the TTL standard, be resent to the equipment of supporting the TTL standard, this serial conversion chip is also used+5V usually, the power supply of+12V.
But for cost consumer electronics industry with keen competition: use above-mentioned integrated chip that cost is improved, make the competitiveness of product forfeiture on market.
Therefore, there is defective in prior art, needs to improve.
The utility model content
In order to reduce cost, the utility model provides a kind of level shifting circuit, it makes up the mode of circuit by adopting discrete devices such as bipolar transistor (Bipolar Junction Transistor), realize the mutual conversion of RS232 level and Transistor-Transistor Logic level, thereby reach the optimized purpose that realizes cost and economic benefit.
Level shifting circuit of the present utility model, it is used to realize the level conversion between RS232 level and the Transistor-Transistor Logic level, described level shifting circuit comprises: the first common emitter switching circuit, this common emitter switching circuit are connected between RS232 level receiving terminal and the Transistor-Transistor Logic level transmitting terminal; When the Transistor-Transistor Logic level transmitting terminal was high level output, this common emitter switching circuit ended, and described RS232 level receiving terminal is a low level; When the Transistor-Transistor Logic level transmitting terminal is low level output, this common emitter switching circuit conducting, described RS232 level receiving terminal is a high level; And the second common emitter switching circuit, this common emitter switching circuit is connected between RS232 level transmitting terminal and the Transistor-Transistor Logic level receiving terminal; When RS232 level transmitting terminal is high level output, this common emitter switching circuit conducting, described Transistor-Transistor Logic level receiving terminal is a low level; When RS232 level transmitting terminal was low level output, this common emitter switching circuit ended, and described Transistor-Transistor Logic level receiving terminal is a high level.
Wherein, the described first common emitter switching circuit comprises transistor Q1, current-limiting resistance R1, divider resistance R2, current-limiting resistance R3, resistance R 4, the emitter of transistor Q1 connects the output of a positive direct-current power supply, cross-over connection has divider resistance R2 between this emitter and its base stage, and the collector electrode of described transistor Q1 connects the output of a negative DC power supply by resistance R 4; The base stage of described transistor Q1 connects described Transistor-Transistor Logic level transmitting terminal by current-limiting resistance R3, and its collector electrode connects described RS232 level receiving terminal by current-limiting resistance R1.
Wherein, the described second common emitter switching circuit comprises transistor Q2, pull-up resistor R5, current-limiting resistance R6 and current-limiting resistor voltage divider R7, and the collector electrode of transistor Q2 connects the output of a positive direct-current power supply by pull-up resistor R5; Cross-over connection current-limiting resistor voltage divider R7 between the base stage of described transistor Q2 and its emitter, and described grounded emitter; The collector electrode of described transistor Q2 connects described Transistor-Transistor Logic level receiving terminal, and its base stage connects described RS232 level transmitting terminal by current-limiting resistance R6.
Wherein, the output voltage of described positive direct-current power supply is more than or equal to 5.0 volts.Wherein, the output voltage of described negative DC power supply value between-15 volts to-5 volts.Described transistor Q1 is a PNP transistor, and described transistor Q2 is a NPN transistor.Wherein, the described first common emitter switching circuit comprises that also one is connected to the shunt capacitance C1 between resistance R 4 and the ground, and the output of described negative DC power supply is by shunt capacitance C1 ground connection.
Wherein, described negative DC power supply is made of a charge-discharge circuit, in this charge-discharge circuit, the voltage of described RS232 level transmitting terminal output is charging capacitor C2 charging, and the electric power storage by this charging capacitor C2 provides required negative DC power supply for the collector electrode of described transistor Q1.Wherein, in described charge-discharge circuit, described RS232 level transmitting terminal connects the negative pole end of a diode D2, and the positive terminal of this diode D2 connects the negative pole end of described charging capacitor C2, and should hold output, the other end ground connection of described charging capacitor C2 as described negative DC power supply.Wherein, in described charge-discharge circuit, the two ends cross-over connection one rectifier diode D1 of described charging capacitor C2, itself and described charging capacitor C2 constitute discharge loop.
The utility model adopts discrete device to make up the change-over circuit of RS232 level and Transistor-Transistor Logic level, and it uses bipolar transistor (Bipolar Junction Transistor) to make up common emitter circuit and realizes that input signal and the anti-phase of output signal and employing external power source (as-12V etc.) provide stable reference logic level.The utility model is owing to adopted the triode transistor and the resistance of middle low power commonly used in circuit design, electric capacity, with low cost, dependable performance, can satisfy consumer electronics product debugging and demands of applications such as set-top box, when producing in enormous quantities, on average save platform, it is very considerable giving the economic benefit that enterprise brought thus.
Description of drawings
Fig. 1 is the structural representation of the utility model embodiment 1;
Fig. 2 is the signal waveforms of RS232 level and Transistor-Transistor Logic level;
Fig. 3 is the structural representation of the utility model embodiment 2.
Embodiment
Below preferred embodiment of the present utility model is described in detail.
Embodiment 1: as shown in Figure 1, level shifting circuit of the present utility model, it is used to realize the level conversion between RS232 level and the Transistor-Transistor Logic level, this circuit comprises: the first common emitter switching circuit 110 and the second common emitter switching circuit 120, common emitter switching circuit 110 are connected between RS232 level receiving terminal RX and the Transistor-Transistor Logic level transmitting terminal TTL_TXD; When Transistor-Transistor Logic level transmitting terminal TTL_TXD was high level output, this common emitter switching circuit ended, and described RS232 level receiving terminal RX is a low level; When Transistor-Transistor Logic level transmitting terminal TTL_TXD is low level output, this common emitter switching circuit conducting, described RS232 level receiving terminal RX is a high level;
The second common emitter switching circuit 120 is connected between RS232 level transmitting terminal TX and the Transistor-Transistor Logic level receiving terminal TTL_RXD; When RS232 level transmitting terminal TX is high level output, this common emitter switching circuit conducting, described Transistor-Transistor Logic level receiving terminal TTL_RXD is a low level; When RS232 level transmitting terminal TX was low level output, this common emitter switching circuit ended, and described Transistor-Transistor Logic level receiving terminal TTL_RXD is a high level.The above-mentioned first common emitter switching circuit 110 and the second common emitter switching circuit 120 can adopt the common emitter switching circuit that is made of PNP transistor and NPN transistor respectively, certainly can also adopt the switching tube of other types to replace, as the field effect transistor of N raceway groove and the field effect transistor of P raceway groove.
As shown in Figure 1, the second common emitter switching circuit 120 that is made of NPN transistor can adopt following concrete mode to realize.This common emitter switching circuit 120 mainly comprises NPN transistor Q2, pull-up resistor R5, current-limiting resistance R6 and current-limiting resistor voltage divider R7, and the collector electrode of NPN transistor Q2 connects the output of a positive direct-current power supply by pull-up resistor R5; Cross-over connection has current-limiting resistor voltage divider R7 between the base stage of NPN transistor Q2 and its emitter, and the grounded emitter of Q2; The collector electrode of NPN transistor Q2 connects Transistor-Transistor Logic level receiving terminal TTL_RXD, and the base stage of Q2 connects RS232 level transmitting terminal TX by a current-limiting resistance R6.Here the NPN transistor Q2 that mentions can adopt NPN type triode 2N5551.The reference power source of being mentioned in this circuit is the positive direct-current power supply, and its output voltage is more than or equal to 5.0 volts, and this can be decided by the level standard of TTL, in Fig. 1, adopts+5 volts positive direct-current power supply.
As shown in Figure 1, the common emitter switching circuit 110 that is made of PNP transistor can adopt following concrete mode to realize.This common emitter switching circuit 110 mainly comprises PNP transistor Q1, current-limiting resistance R1, divider resistance R2, current-limiting resistance R3, resistance R 4, the emitter of PNP transistor Q1 connects the output of above-mentioned positive direct-current power supply, cross-over connection has divider resistance R2 between the emitter of PNP transistor Q1 and its base stage, and the collector electrode of PNP transistor Q1 connects the output of a negative DC power supply by resistance R 4; The base stage of PNP transistor Q1 connects described Transistor-Transistor Logic level transmitting terminal TTL_TXD by another current-limiting resistance R3, and its collector electrode connects described RS232 level receiving terminal RX by another current-limiting resistance R1.Two reference power sources being mentioned in this circuit: a positive direct-current power supply, its output voltage are more than or equal to 5.0 volts, and this can be decided by the level standard of TTL; Another is negative DC power supply, and its output voltage is value between-15 volts to-5 volts, and this can be decided by the level standard of RS232; In Fig. 1, adopt+5 volts positive direct-current power supply, adopt-12 volts negative DC power supply.
Below specify the operation principle of the utility model level shifting circuit shown in Figure 1.Under the initial condition, the level value of PC end serial ports RS232 level transmitting terminal TX is generally-9.8V about, be in the high logic state of RS232.For NPN transistor Q2, its input is a base stage, and the transmission signal that connects PC RS232 serial ports, its output is a collector electrode, and the received signal that connects the equipment of supporting the TTL standard, its emitter constitutes the common emitter switching circuit and has realized the anti-phase of input signal and output signal as public pole ground connection.
When the signal of RS232 level transmitting terminal TX output be-9.8V or-12V, when promptly being in the logical one state of RS232 level (its RS232 adopts negative logic), then the base voltage of NPN transistor Q2 is less than emitter voltage, NPN transistor Q2 is in cut-off state, therefore support the Transistor-Transistor Logic level receiving terminal TTL_RXD of the equipment of TTL standard to be connected with+5.0V power supply by resistance R 5, the signal of Transistor-Transistor Logic level receiving terminal TTL_RXD is in+level state of 5.0V, promptly be in the logical one state of Transistor-Transistor Logic level, this logical one of just having finished the RS232 signal that an equipment of supporting the RS232 standard sends is converted to the process of the logical one of the TTL signal that the equipment of supporting the TTL standard can discern;
When the signal of RS232 level transmitting terminal TX output be+9.8V or+12V, when promptly being in the logical zero state of RS232 level, then the base voltage of NPN transistor Q2 is greater than emitter voltage, NPN transistor Q2 is conducting then, directly Transistor-Transistor Logic level receiving terminal TTL_RXD is moved on the GND, making the Transistor-Transistor Logic level receiving terminal TTL_RXD of the equipment of supporting the TTL standard is 0V, promptly be in the logical zero state of Transistor-Transistor Logic level, this logical zero of just having finished the RS232 signal that an equipment of supporting the RS232 standard sends is converted to the process of the logical zero of the TTL signal that the equipment of supporting the TTL standard can discern, resistance R 7 plays the effect of dividing potential drop current limliting herein, prevents that the excessive NPN transistor Q2 that causes of electric current from being burnt.
For PNP transistor Q1, its input is a base stage, and the Transistor-Transistor Logic level transmitting terminal TTL_TXD that connects the equipment of supporting the TTL standard, its output is a collector electrode, and the RS232 level receiving terminal RX that connects the PC end, its emitter connects+the 5.0V power supply as public pole, constitutes common emitter circuit and has realized the anti-phase of input signal and output signal.
The signal of exporting as the Transistor-Transistor Logic level transmitting terminal TTL_TXD of the equipment of supporting the TTL standard is+3.3V, when being in the logical one state of Transistor-Transistor Logic level, the voltage of divider resistance R2 one end is+5.0V, the base voltage Vb=(5.0-3.3) of PNP transistor Q1 * R3/ (R2+R3)+3.3=1.7 * 0.825+3.3=4.7V then, the emitter of PNP transistor Q1 is received+the 5.0V power supply simultaneously, the emitter voltage of this transistor Q1 is+5.0V, do not satisfy this transistor turns condition, then PNP transistor Q1 ends, under the effect of reference power source-12V, the signal of RS232 level receiving terminal RX output is in-stable level of 12V, promptly be in the logical one state of RS232 level, the logical one of so just having finished the TTL signal that an equipment of supporting the TTL standard sends is converted to the process of the logical one of the RS232 signal that the equipment of supporting the RS232 standard can discern;
The signal of exporting as the Transistor-Transistor Logic level transmitting terminal TTL TXD that supports the TTL standard is 0V, and when being in the logical zero state of Transistor-Transistor Logic level, this moment, the base voltage of PNP transistor Q1 was 0V; The emitter-base bandgap grading of PNP transistor Q1 is received+the 5.0V power supply simultaneously, the emitter voltage of PNP transistor Q1 is+5.0V, then PNP transistor Q1 conducting, owing to draw on effect and the PN junction of PNP transistor Q1 on the+5.0V power supply and have conduction voltage drop, the A point voltage is+4.7V in the circuit, RS232 level receiving terminal RX then is+high level of 4.7V, promptly be in the logical zero state of RS232 level, this logical zero of just having finished the TTL signal that an equipment of supporting the TTL standard sends is converted to the process of the logical zero of the RS232 signal that the equipment of supporting the RS232 standard can discern.
By above analysis as seen, above-mentioned level shifting circuit can realize that the mutual conversion of Transistor-Transistor Logic level and RS232 level is to satisfy the equipment of supporting the RS232 standard and the demand of utilizing the communication between devices of TTL logical signal current potential.
As shown in Figure 1, the output of above-mentioned negative DC power supply is by a bypass capacitor C 1 ground connection, and promptly the collector electrode of PNP transistor Q1 is by resistance R 4 ground connection, and this shunt capacitance is used to protect PNP transistor Q1, removes high-frequency noise.This shunt capacitance C1 adopts CE 127.
Embodiment 2: as shown in Figure 3, with the difference of the foregoing description 1 be: negative DC power supply is made of a charge-discharge circuit in the present embodiment, in this charge-discharge circuit, the voltage of RS232 level transmitting terminal TX output is charging capacitor C2 charging, and provides required negative DC power supply by this charging capacitor C2 electric power storage for the collector electrode of PNP transistor Q1.Other structural detail and annexation thereof are identical with embodiment 1.Present embodiment discharges and recharges for level shifting circuit provides negative supply by charging capacitor C2's, thereby has avoided building again the negative supply circuit.The charging capacitor C2 here can adopt above-mentioned shunt capacitance C1, or adopts other electric capacity of CE 127 models, and its value can be 10 microfarads.
Above-mentioned charge-discharge circuit can make up by diode component, RS232 level transmitting terminal TX connects the negative pole end of a diode D2, the positive terminal of this diode D2 connects the end of charging capacitor C1, and should organize the collector electrode that R4 connects PNP transistor Q1, the other end ground connection of charging capacitor C2 as the output of described negative DC power supply by electricity by end.The two ends cross-over connection one rectifier diode D1 of charging capacitor C2, itself and charging capacitor C2 constitute discharge loop.
In conjunction with Fig. 3, specify the operation principle of embodiment 2 circuit.
In circuit shown in Figure 3, under the initial condition, the signal of PC end RS232 level transmitting terminal TX output is-the 12V level, when being in logical one, diode D2 conducting, charging capacitor C2 begins charging, and the B point voltage reaches-12V, under this kind situation, this circuit can provide stable-12V reference level.The signal of exporting as RS232 level transmitting terminal TX transfers to+the 12V level, when being in logical zero, this moment, diode D2 ended, under this condition, if support that the signal of the Transistor-Transistor Logic level transmitting terminal TTL_TXD output of TTL standard device is the 3.3V level, when being in logical one, then PNP transistor Q1 ends, the A point voltage is-12V, it is to provide negative direct current reference power source by charging capacitor C2, the signal of RS232 level receiving terminal RX output is-12V, promptly be in the logical one state of RS232 level, the logical one that so also can finish the TTL signal that an equipment of supporting the TTL standard sends is converted to the process of the logical one of the RS232 signal that the equipment of supporting the RS232 standard can discern.
PNP transistor Q1 in the level shifting circuit that the utility model proposed and NPN transistor Q2 can use low-power transistor commonly used to go to replace, and they can well be worked, and can not influence application and debugging on consumption electronic product.
Should be understood that, for those of ordinary skills, can be improved according to the above description or conversion, and all these improvement and conversion all should belong to the protection range of the utility model claims.
Claims (10)
1, a kind of level shifting circuit is used to realize the level conversion between RS232 level and the Transistor-Transistor Logic level, it is characterized in that it comprises:
The first common emitter switching circuit, this common emitter switching circuit are connected between RS232 level receiving terminal and the Transistor-Transistor Logic level transmitting terminal; When the Transistor-Transistor Logic level transmitting terminal was high level output, this common emitter switching circuit ended, and described RS232 level receiving terminal is a low level; When the Transistor-Transistor Logic level transmitting terminal is low level output, this common emitter switching circuit conducting, described RS232 level receiving terminal is a high level;
And the second common emitter switching circuit, this common emitter switching circuit is connected between RS232 level transmitting terminal and the Transistor-Transistor Logic level receiving terminal; When RS232 level transmitting terminal is high level output, this common emitter switching circuit conducting, described Transistor-Transistor Logic level receiving terminal is a low level; When RS232 level transmitting terminal was low level output, this common emitter switching circuit ended, and described Transistor-Transistor Logic level receiving terminal is a high level.
2, level shifting circuit according to claim 1, it is characterized in that, the described first common emitter switching circuit comprises transistor Q1, current-limiting resistance R1, divider resistance R2, current-limiting resistance R3, resistance R 4, the emitter of transistor Q1 connects the output of a positive direct-current power supply, cross-over connection has divider resistance R2 between this emitter and its base stage, and the collector electrode of described transistor Q1 connects the output of a negative DC power supply by resistance R 4; The base stage of described transistor Q1 connects described Transistor-Transistor Logic level transmitting terminal by current-limiting resistance R3, and its collector electrode connects described RS232 level receiving terminal by current-limiting resistance R1.
3, level shifting circuit according to claim 2, it is characterized in that, the described second common emitter switching circuit comprises transistor Q2, pull-up resistor R5, current-limiting resistance R6 and current-limiting resistor voltage divider R7, and the collector electrode of transistor Q2 connects the output of a positive direct-current power supply by pull-up resistor R5; Cross-over connection current-limiting resistor voltage divider R7 between the base stage of described transistor Q2 and its emitter, and described grounded emitter; The collector electrode of described transistor Q2 connects described Transistor-Transistor Logic level receiving terminal, and its base stage connects described RS232 level transmitting terminal by current-limiting resistance R6.
4, according to claim 2 or 3 described level shifting circuits, it is characterized in that the output voltage of described positive direct-current power supply is more than or equal to 5.0 volts.
5, level shifting circuit according to claim 2 is characterized in that, the output voltage of described negative DC power supply is between-15 volts to-5 volts.
6, level shifting circuit according to claim 3 is characterized in that, described transistor Q1 is a PNP transistor, and described transistor Q2 is a NPN transistor.
7, level shifting circuit according to claim 2 is characterized in that, the described first common emitter switching circuit comprises that also one is connected to the shunt capacitance C1 between resistance R 4 and the ground, and the output of described negative DC power supply is by shunt capacitance C1 ground connection.
8, level shifting circuit according to claim 2, it is characterized in that, described negative DC power supply is made of a charge-discharge circuit, in this charge-discharge circuit, the voltage of described RS232 level transmitting terminal output is charging capacitor C2 charging, and the electric power storage by this charging capacitor C2 provides required negative DC power supply for the collector electrode of described transistor Q1.
9, level shifting circuit according to claim 8, it is characterized in that, in described charge-discharge circuit, described RS232 level transmitting terminal connects the negative pole end of a diode D2, the positive terminal of this diode D2 connects the negative pole end of described charging capacitor C2, and should hold output, the other end ground connection of described charging capacitor C2 as described negative DC power supply.
10, level shifting circuit according to claim 9 is characterized in that, in described charge-discharge circuit, and the two ends cross-over connection one rectifier diode D1 of described charging capacitor C2, itself and described charging capacitor C2 constitute discharge loop.
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| CNU2007201727127U CN201113972Y (en) | 2007-10-19 | 2007-10-19 | Level switching circuit |
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| CNU2007201727127U CN201113972Y (en) | 2007-10-19 | 2007-10-19 | Level switching circuit |
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| CN103066986A (en) * | 2012-12-14 | 2013-04-24 | 深圳市新国都技术股份有限公司 | Positive-negative logic level conversion switching circuit |
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| CN103138739B (en) * | 2013-03-22 | 2016-03-30 | 福建联迪商用设备有限公司 | Serial port level conversion method and circuit |
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| CN104868904A (en) * | 2015-05-29 | 2015-08-26 | 华为技术有限公司 | Level converting circuit and device |
| CN104868904B (en) * | 2015-05-29 | 2018-03-13 | 华为技术有限公司 | A kind of level shifting circuit and device |
| CN105159854A (en) * | 2015-07-29 | 2015-12-16 | 深圳市芯智科技有限公司 | Level switching circuit and method for communication between computer and set-top box |
| CN105159854B (en) * | 2015-07-29 | 2018-07-13 | 深圳市芯智科技有限公司 | Level shifting circuit and method for computer and set-top box communication |
| CN107491155A (en) * | 2017-07-05 | 2017-12-19 | 北汽福田汽车股份有限公司 | The hard reset control system and method for board information terminal |
| CN107491155B (en) * | 2017-07-05 | 2020-06-16 | 北汽福田汽车股份有限公司 | Hard reset control system and method for vehicle-mounted information terminal |
| CN109213711A (en) * | 2018-08-28 | 2019-01-15 | 郑州云海信息技术有限公司 | A kind of serial interface switching circuit |
| CN113742003A (en) * | 2021-09-15 | 2021-12-03 | 深圳市朗强科技有限公司 | Program code execution method and device based on FPGA chip |
| CN113742003B (en) * | 2021-09-15 | 2023-08-22 | 深圳市朗强科技有限公司 | Program code execution method and device based on FPGA chip |
| CN114443535A (en) * | 2022-01-19 | 2022-05-06 | 苏州冠德能源科技有限公司 | Serial data communication port conversion circuit and conversion device |
| CN114443535B (en) * | 2022-01-19 | 2024-01-30 | 苏州冠德能源科技有限公司 | Serial data communication port conversion circuit and conversion device |
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