CN103701440A - Switch capable of maintaining zero current - Google Patents
Switch capable of maintaining zero current Download PDFInfo
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- CN103701440A CN103701440A CN201310540093.2A CN201310540093A CN103701440A CN 103701440 A CN103701440 A CN 103701440A CN 201310540093 A CN201310540093 A CN 201310540093A CN 103701440 A CN103701440 A CN 103701440A
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Abstract
The invention discloses a switch capable of maintaining zero current. A double-pole switch has a characteristic of maintaining a current close to zero, and is low in output impedance when in an on state and the impedance approaches the infinity when the double-pole switch is in an off state. The switch is sensitive to a control signal, and a voltage stabilizing power supply is applied on a load. The switch comprises a conduction detecting circuit and a switching circuit, a detection starting circuit is individually driven by the control signal, the switching circuit is driven by the power supply, but when the switch is turned off, the power supply usually does not have maintaining current. The switching circuit comprises an accelerating circuit, a positive feedback circuit is adopted to obtain high current gain, and a circuit with the switch is rapidly turned off, and the switch can be rapidly turned on through the accelerating circuit.
Description
Technical field
The present invention is conventionally relevant with switch, especially quick single-chip switching, and in off-state, this switch does not need quiescent bias current.
Background technology
Controlled application, removes load excitation, and for example electronic circuitry, can carry out with a large amount of different modes, and mechanical switch needs the electrical contact in user's moving switch, and power supply is connected to load.An electronic control signal being provided by user of electromagnetic relay response, closes one group of contact, for power supply is connected to load.Although these machineries and electromechanical structure, there is the characteristic of certain perfect switch, as approach infinite disconnection impedance, approach zero conduction impedance, with zero quiescent current, but they also have certain defect, as be subject to mechanical breakdown, need the control signal of appropriateness excitation, the very slow response time, switch bounce-back, through the ON/OFF week after date of certain number of times, switch performance declines.
In bipolar and MOS or DMOS technology, some solid-state switches are available not long ago.Although MOS type switch feature is low quiescent current, its deficiency is shortage speed, for example switching time in 35 microseconds between 50 microseconds.Although this speed is compared to machinery and electric mechanical switch technological improvement, to some application still too slow.
The conducting of this double-pole switch is very quick, only has the switching time of 1 microsecond, but needs significant wait or quiescent current.Current double-pole switch technology can be improved by conventional method, can under lower quiescent current, turn round.But, use these conventional methods, can sacrifice speed, namely, the switching speed of the double-pole switch of these improveds is approximate with the switching time of MOS devices switch.
The advantage of solid-state switch comprises does not have mechanical type fault, needs low level control signal, less physical size.
Therefore a solid-state double-pole switch is very desirable, and this switch has, and fast switching time and need low standby current or zero dimension to hold the advantage of electric current, in addition, off-state has infinitely-great impedance, conducting state zero impedance.
Summary of the invention
An object of the present invention is to provide a double-pole switch, it has high switching speed and low-down static state or maintains electric current demand.
Another object of the present invention is to provide a double-pole switch, and it has zero quiescent current demand
Another object of the present invention is to provide a double-pole switch, and its adopts regenerative circuit to carry out driving switch part fast, from standby mode, enters conducting state, these parts in this pattern completely in off-state.
Another object of the present invention is to provide a solid-state switch, and it has Low ESR substantially in conducting state, in off-state, substantially has infinitely-great impedance.
Another object of the present invention is to provide a solid-state switch, and after controlled signal excitation, this switch improves output level with positive feedback.
A further object of the present invention is to provide a double-pole switch, and it adopts signal for faster, makes the part conventionally disconnecting promptly enter work.
A further object of the present invention is to provide a double-pole switch, and it comprises open circuit, at switch off period, and promptly discharging switch element, and turn-off delay circuit, at switch element interdischarge interval, turn-off delay circuit is to open circuit energy supply.
Technical solution of the present invention is:
The other problems of foreground and prior art switch, by solid-state device of the present invention, be overcome, solid-state device is to a control signal sensitivity, control signal for by power supply to load energy supply, solid-state device comprises: checkout gear, reception control signal detects the existence of conducting state in control signal, produce a pumping signal as response, in addition, initial, checkout gear is driven separately by control signal; By the device of power drives, be connected between power supply and load, and responsive to pumping signal, be used for to load energy supply, when receiving described pumping signal, power supply device is changed to conducting state from off-state, further, in off-state, power supply device does not need quiescent bias current.
In an embodiment of the present invention, comprise accelerator, when power supply device is connected, running, makes power supply device enter rapidly operation.
In preferential embodiment of the present invention, power supply device comprises reference section and control section, and reference section provides reference signal to control section, and control section is for controlling the application to load energy supply by power supply.Reference section adopts the design of self―sustaining, and after reference section is at the beginning by signal for faster conducting, self―sustaining entry into service, maintains reference section in operating condition.Control section adopts positive feedback to increase the output current capacity of switch, adopts negative feedback that stability is provided.
Preferential embodiment of the present invention further comprises, control signal is broken to the device of state sensitivity, carrys out disabled switch.Also have a delay circuit, this circuit turns round when switch is forbidden, within a bit of time to reference section energy supply.This is in order to allow voltage stabilizing open circuit partly, in a kind of quick and predictable mode, forces the output of pressurizer to become off-state.
What further comprise also has error detect circuit for detection of the mistake in switching manipulation.
Consistent with the method in the present invention, double-pole switch is by providing a conduction detection circuit to move, and this circuit is driven separately by control signal, detects the conducting state in control signal, drives connecting circuit to enter mode of operation, and wherein connecting circuit is to load energy supply.Connecting circuit is that type that does not need to maintain electric current in off-state.Incentive step can comprise, sends signal for faster make connecting circuit enter rapidly operating state to connecting circuit.
An embodiment of the inventive method, adopts positive feedback at connecting circuit, increases output level, has adopted self―sustaining circuit, keeps connecting circuit work after incentive step.Use positive feedback has increased the efficiency of double-pole switch, obtains the output level of expectation by reducing minimum offset signal required in connecting circuit.
The further reinforcement of the inventive method, comprises discharge circuit and delay circuit is provided, and at the Disconnected mode of switch, allows element electric discharge, the element of switch handle high current in connecting circuit.In this way, these elements can enter off-state more quick and completely.
These and other object, consider below relevant of the present invention some preferably embody the detailed description with accompanying drawing, the features and advantages of the invention will be easier to understand.
Contrast patent documentation: CN2431680Y has the modified form operational amplifier 00232937.9 of zero current sinking and stable output, and CN2896699Y shutdown zero consumes touching electronic switch 200620050074.7.
Accompanying drawing explanation:
Figure 1A is symbolic description of the present invention.
Figure 1B is simplified block diagram of the present invention.
Fig. 2 is the more detailed block diagram of the present invention.
Fig. 3 A is the detailed schematic diagram of control signal testing circuit of the present invention.
Fig. 3 B is the detailed schematic diagram of reference circuit of the present invention.
Fig. 3 C is the detailed schematic diagram of switch/regulating circuit of the present invention.
Fig. 3 D is the detailed schematic diagram of disconnection detection circuit of the present invention.
Fig. 3 E is the detailed schematic diagram of error flag circuit of the present invention.
Fig. 3 F is the detailed schematic diagram of thermal protection circuit of the present invention.
Embodiment:
About Figure 1A, illustrated the symbolic functional description of double-pole switch of the present invention.10 pairs of control signal sensitivities of switch, control signal is applied in terminal 12.Power supply is connected to terminal 14, and the power supply that is applied to load is provided on terminal 16.Control signal makes terminal 14 be connected to terminal 16 by causing signalling channel 18 to close.
About Figure 1B, a preferred version of the present invention, comprises conduction detection circuit 20 in function, reference circuit 22, switch/regulating circuit 24, accelerating circuit 26, disconnection detection circuit 28, turn-off delay circuit 30 and error detect circuit 32.Control signal is applied to conduction detection circuit 20 via terminal 12.Control circuit is also applied to disconnection detection circuit 28 by same terminal.
It should be noted, conduction detection circuit 20 obtains excitation from control signal individually at first on terminal 12.Also it should be noted that residual circuit piece obtains excitation from power supply, at this example,
v s be applied to terminal 14.
It should be noted the static state of switch, circuit block 22 to 32 preferably disconnects completely.That is to say, in the off-state of switch 10, they do not attract any electric current from power supply except leakage current.Only have conduction detection circuit 20 on terminal 12, to detect after the conducting state in control signal, piece 22 to 32 just driven runnings.
When operation, when conducting state being detected, conduction detection circuit 20 activates accelerating circuit 26.Conversely, accelerating circuit 26 sends signal for faster to reference circuit 22, switching circuit 24, disconnection detection circuit 28 and error detect circuit 32.Accelerating circuit 24 turns back to conduction detection circuit 20 signal for faster, makes it locked in conducting state.Meanwhile, turn-off delay circuit 30 is initialised, and receives the signal from disconnection detection circuit 28.At this moment, switch/regulating circuit 24 provides an output signal to load
.Switch 10 keeps this state until error detect circuit 32 mensuration make a mistake or until disconnection detection circuit 28 detects off-state on terminal 12.
When switch conduction, conduction detection circuit 20 will be insensitive to the off-state on terminal 12, because it is locked in conduction mode.But disconnection detection circuit 28 will react and send cut-off signal to switch/regulating circuit 24 and turn-off delay circuit 30 off-state.Response cut-off signal, switch/regulating circuit 24 will disconnect, and turn-off delay circuit 30 can start break step at reference circuit 22.
Turn-off delay circuit 30 guarantees that switch can disconnect fast, by maintain for excitation, by the discharge circuit in switch/regulating circuit 24, so element has very long opening time, can be disconnected energetically.Once arrived time of delay default in turn-off delay circuit 30, each piece all can disconnect.State when at that time, the state of each circuit block starts with circulation is identical.
When making a mistake, error detect circuit can be notified disconnection detection circuit 28.Disconnection detection circuit 28 will be with the response of a kind of method, its response when the method is similar to it detects off-state on terminal 12.
Conventionally when reference circuit 22 running, provide the reference signal that comprises reference voltage and offset signal, by switch/regulating circuit 24, disconnection detection circuit 28, error detect circuit 32 and turn-off delay circuit 30 are used.The reference signal that switch/regulating circuit 24 receives from reference circuit 22 is applied to load as response using excitation in addition on terminal 16.
Switch/regulating circuit 24 comprises a positive feedback loop, and it,, there being low level output to drive under bias current existence, has increased the output driving force of device, and a negative feedback loop, and it has guaranteed circuit energy stable operation under different operating conditions.
Above self―sustaining circuit and feedback circuit allow reference circuit 22 and switch/regulating circuit 24 can have off-state, under this state, do not need to maintain electric current or quiescent current.
As mentioned above, disconnection detection circuit 28 detects off-state on terminal 12.When sort signal is detected, disconnection detection circuit 28 provides a signal to reference circuit 22, overcomes the self―sustaining ability of reference circuit.Disconnection detection circuit 28 also provides a signal to switching circuit 24, and in fact this signal has overcome regenerative circuit wherein.These signals have also started discharge circuit, and by this circuit, reference circuit 22 and switch/regulating circuit 24 are promptly disconnected.
Because solid-state element, for example the handle high current element in switch/regulating circuit 24, will often show one important period, during this period of time in, there is off-state, discharge circuit is used for accelerating to disconnect these devices.30 runnings of turn-off delay circuit, after the off-state of receiving from disconnection detection circuit 28, keep reference circuit 22 in the given time in operating condition.This makes the discharge circuit of switch/regulating circuit 24 inside, fully forbids high current processing element work wherein.
Present double-pole switch of the present invention 10 will be described with more detailed energy supply details.Fig. 2 has illustrated the distribution of the function element of this switch, and detailed circuit diagram 3A is to 3F, in order to explain simply the operation of double-pole switch of the present invention.Fig. 3 A is the detailed circuit diagram of conduction detection circuit 20, Fig. 3 B is the detailed circuit diagram of accelerating circuit 26 and reference circuit 22, Fig. 3 C is the detailed circuit diagram of switch/regulating circuit 24, Fig. 3 D is the detailed circuit diagram of disconnection detection circuit 28, finally, Fig. 3 E and Fig. 3 F provide the detailed circuit diagram of error detect circuit 32.
Conduction detection circuit 20:
After one period of short time, internal reference circuit 22 enters running during this period of time, and reference circuit 22 provides an inhibit signal to conducting testing circuit 20.This signal-inhibiting conduction detection circuit working, and prevent any control signal on its response terminal 12, as long as inhibit signal is provided by reference circuit 22.
Reference circuit 22:
About the reference circuit 22 of Fig. 2, accelerating circuit 26 by line 34 to providing signal for faster with reference to holding circuit 42.Conversely, with reference to holding circuit 42, pass through line 33 to reference circuits 36 energy supplies.At preferred version of the present invention, the reference voltage of generation is a band gap voltage.
Reference voltage is applied to a NPN type bias generating circuit 38 by line 37.At preferred version of the present invention, NPN bias circuit 38 forms the part of a series of current mirrors, and current mirror is at reference circuit 22, in switch/regulating circuit 24 and error detect circuit 32, therein as current source.NPN type bias circuit 38 also, by line 39, provides bias current to PNP bias circuit 40.
Conversely, positive-negative-positive bias circuit 40, at reference circuit 22, arranges other bias current level in disconnection detection circuit 28 and error detect circuit 32.These bias currents one of them, by line 41, offer with reference to holding circuit 42, this offset signal is for generation of pumping signal, this pumping signal provides by line 33, maintains reference voltage circuit 36 in conducting state.
Another offset signal directly offers reference voltage circuit 36 by PNP bias circuit by line 49.This also maintains reference voltage circuit in conducting state.
Another bias current is applied to turn-off delay circuit 30 by line 43.Turn-off delay circuit 30 provides a signal as response by line 47 to conduction detection inhibit circuit 44.Conversely, conduction detection inhibit circuit 44 provides inhibit signal by line 31 to conducting testing circuit 20, as mentioned above, is used for locking it in conducting state.
On online 45, the bias current being provided by positive-negative-positive bias circuit, by a comparator of 32 li of error detect circuits, the levels of current of setup and use.
Finally, as mentioned above, turn-off delay circuit 30 reference circuits 22 are operated in the Disconnected mode of switch 10, when in switch, handle high current element is disconnected, to reference voltage circuit 36 energy supplies.
Switch/regulating circuit 24 comprises output driving circuit 46, and output driving circuit 46 provides the actual output on terminal 16 to load; Adjuster 48, it is by output driving circuit 46, and regulation and control offer the output of load; Drive loop circuit 50, the output level being provided by output driving circuit 46 is provided for it.
Regulating circuit 48 and the offset signal that drives loop circuit 50 to receive from NPN type bias circuit 38 by line 52.This offset signal of regulating circuit 48 use arranges a reference voltage level, and the output of output driving circuit 46 is compared with it.
Drive loop circuit 50 to adopt positive feedback to improve the output current level of output driving circuit 46, if be much higher than directly, by offset signal, carry out 46 obtainable levels of current of driver output drive circuit.By driving loop circuit 50 and regulating circuit 48 to adopt negative feedback, carry out stable loop.
Regulating circuit 48, by driving loop circuit 50 being applied to respectively on the signal online 56 as positive feedback signal and line 57, controls the output of output driving circuit 46.These modification of signal are provided to the driving signal of output driving circuit 46.
At first, in the running, switch/regulating circuit 24 receives a signal for faster from accelerating circuit by line 58.Drive loop circuit 50 by driving signal application to respond this signal for faster to output driving circuit 46 one.Conversely, output driving circuit 46 enters running, to load, provides excitation.It also provides signal by line 60 and line 61 to regulating circuit, and these signals are directly proportional to the output current that offers load.Regulating circuit 48 is respectively by line 56 and line 57, to driving loop circuit 50 to provide positive feedback signal and negative-feedback signal to respond these signals.
Disconnection detection circuit 28:
Off-state in the disconnection detection electric circuit inspection control signal of Fig. 2, control signal is applied to terminal 12.
More particularly, at Disconnected mode, a cut-off signal offers the reference holding circuit 42 of reference circuit 22 by line 62.This signal, by reference to holding circuit 42, removes the excitation that offers reference voltage circuit 36.
Cut-off signal is also applied to turn-off delay circuit 30 by line 64.This signal, by positive-negative-positive bias circuit 40, in one period of scheduled time after Disconnected mode starts, continues excitation to be applied to reference voltage circuit 36.This makes the circuit in reference circuit 22 downstreams fully discharge and disconnect.
As previously mentioned, the problem running in double-pole switch operation, is the time quantum that the different piece of switching circuit need to disconnect, and switch object is to disconnect completely at "off" state.Once Disconnected mode starts, if all excitations remove from switch simultaneously, some part of switch will maintain conducting state.For example, if use to drive the positive-negative-positive triode of large current load, the opening time of these devices, compare very large with the opening time of the device of the little current signal of processing in residual circuit.If switch is disconnected completely, before removing all excitations, should provide time enough to discharge and disconnect such positive-negative-positive triode.
At Disconnected mode, cut-off signal, also by turn-off delay circuit 28, is applied to and drives loop circuit 50 and regulating circuit 48, carries respectively from line 66 and 68.Cut-off signal on line 66 is used for forbidding the driving signal by driving loop circuit 50 to provide to output driving circuit 46.Cut-off signal on line 68 activates output and drives discharge circuit, and conversely, this circuit discharges output driving circuit by line 69.
At Disconnected mode, on disconnection detection circuit 28 online 70, provide an inhibit signal to accelerating circuit 26, when implementing break step, prevent that power supply transient state from starting wrong conducting state.
During initial running, the signal for faster that disconnection detection circuit 28 receives from accelerating circuit 26 by line 72, this signal makes disconnection detection circuit 28 enter running.A bias current is provided on online 45, as discussed above, is used for arranging the condition of work of circuit.
The reference signal that disconnection detection signal also receives from reference voltage circuit 36 by line 37.Disconnection detection circuit 28, this reference level and the control signal comparison receiving on terminal 12, determines whether off-state is present in control signal.In preferred version of the present invention, control signal can be provided by gate, and gate provides logical one state and logical zero state.Embodiment as herein described, conduction detection circuit 20 and disconnection detection circuit 28 are using logical one state as conducting state, using logical zero state as off-state.
Error detect circuit 32:
About the error detect circuit 32 of Fig. 2, it has two functional blocks, error flag circuit 76 and thermal protection circuit 78.Different error conditions causes the difference of switch of the present invention to disconnect condition.
Whenever error detect circuit 76 detects an overvoltage condition, or problems of excessive heat detected when thermal protection circuit 78, all can to disconnection detection circuit 28, provide suitable signal by line 64, carry out the Disconnected mode of starting switch.At Disconnected mode, output driving circuit 46 is disconnected, and error flag is set up, and line 98 and reference circuit 22 keep conducting to come to error flag energy supply.
Whenever there is ground short circuit, only have at first error flag to be set up.If but short-circuit condition maintains one period of rise time, thermal protection circuit 78 will turn round and cause off-state as above.
Whenever the output short-circuit of power supply being detected, reference voltage will be latched at conducting state, to error flag energy supply until mistake be corrected.Whenever output no-load, only have error flag to be set up, switch keeps running.
In Fig. 2, can see the signal for faster that error flag circuit 76 and thermal protection circuit 78 receive from accelerating circuit 26 by line 84 and line 86 respectively.On online 52, receive the bias current from NPN type bias circuit 38, the condition of work of circuit is set.
On error flag circuit 76 online 98, provide error flag; Under overvoltage condition, provide on online 80 one to cover signal to thermal protection circuit 78.
Talk about now Fig. 3 A to Fig. 3 F, will describe in more detail circuit of the present invention.
Fig. 3 A and Fig. 3 B, accelerating circuit 26:
About Fig. 3 A and Fig. 3 B, accelerating circuit is presented in the dotted line frame that is labeled as 26.When threshold detection circuit 20 detects the conducting state in control signal, by transistor 110 and diode-connected transistor 111, provide an electric current.The base stage of transistor 118 is connected to transistor 111, forms a current mirror, and the electric current of transistor 118 is just directly proportional to the electric current in transistor 111 collector electrodes like this.The electric current of transistor 118 is by line 27, and from Fig. 3 B, the base stage of transistor 120 flows through technotron 403.In conducting phase of the present invention, transistor 116 is in off-state, and transistor 116 is also connected to transistor 118 by technotron 403.
At preferred version of the present invention, technotron is used for the various NPN type devices of the different circuit of error protection.Therefore when need to understand the technotron described in literary composition carries out such function.
A collector electrode of transistor 120 turns back to the disconnection detection circuit 20 in Fig. 3 A by line 29.Conversely, the electric current in line 29 offers the collector electrode of transistor 111 by technotron 402.This forms a positive feedback current loop, and it is used for maintaining transistor 111 and 118 in conducting state, keeps flowing out the electric current of transistor to 120 and 121 different collector electrodes.By this way, conduction threshold testing circuit 20 is locked in conducting state, and this state is independent of the signal on terminal 12.
The conduction detection circuit of Fig. 3 A and description in the reference of quoting have a little different.More specifically, wherein described circuit does not comprise above-described positive feedback loop.On the contrary, transistor
, consistent with transistor 110, to turn round into load, this load is formed by the resistance R 5 and the R6 that connect.Further, transistor
, the reference section of realizing circuit lags behind.On the contrary, transistor 111 is as transistor 110(
) load, produce the drive current of transistor 120 and 121.Conversely, transistor 120 replaces transistor 110 with respect to the position of transistor 111 effects, and by a signal driver, this signal is proportional to the electric current that flows through transistor 111, completes a positive feedback loop.Aspect every other, the circuit of above-mentioned incorporated by reference and the here circuit of Fig. 3 A, in an identical manner running.
Fig. 3 B reference circuit 22:
As previously mentioned, flow out the electric current of accelerating circuit 26 to various other circuit blocks of switch of the present invention, initial Continuity signal is provided.A transistor of transistor 121 is applied to reference circuit 22 a signal for faster by line 34.This signal receives at the referenced holding circuit 42 of base stage of transistor 129.
This reference voltage offers on NPN type bias circuit 38, online 52 and produces a bias voltage signal, and NPN type bias circuit 38 comprises transistor 140 and the current mirror transistor 141 of diode connection.Transistor 141, by field effect transistor 407, provides a bias current to PNP bias circuit 40.Positive-negative-positive bias circuit comprises, the PNP transistor 146 of diode connection and current mirror transistor 144 and 145.
Excitation is also by offering reference voltage circuit 36 on positive-negative-positive bias circuit 40 online 49.
In this way, once receive that one from the acceleration pulse of accelerating circuit 26, reference voltage circuit 36, NPN bias circuit 38, PNP bias circuit 40 and working in the mode of self―sustaining with reference to holding circuit 42, maintains reference voltage circuit 36 in working order.
Along with reference circuit 22 enters running, from the signal for faster of accelerating circuit 26, become unnecessary.This moment, conduction detection inhibit circuit 44 is forbidden 20 work of conduction detection circuit.Conduction detection inhibit circuit 44, by the current excitation in a collector electrode of transistor 144, obtains excitation by line 43 via turn-off delay circuit 30.
In turn-off delay circuit 30, this electric current is used for opening transistor 136.Flow out the electric current of transistor 136 emitters by line 47, open the transistor 143 and 142 of conduction detection inhibit circuit 44.The collector current that flows out transistor 142 provides on online 31, is used for driving the transistor 119 of conduction detection circuit 20 in Fig. 3 A.Conversely, this causes transistor 119 and 117 to forbid 20 work of conduction detection circuit.
More specifically, the collector and emitter of transistor 119 is connected in the base stage and emitter of transistor 111 and transistor 118.Similarly, the collector and emitter of transistor 117 is connected on current mirror, and current mirror is at the upstream extremity of conduction detection circuit 20.When the base stage of the signal application from transistor 142 to transistor 117 and 119, the current mirror of upstream and transistor 111,118 are disconnected.
Get back to Fig. 3 B, the transistor 143,142 of conduction detection inhibit circuit 44 connects provides a short delay, makes reference circuit 22 stable before inhibit pulse sends.Obtain this period of time of delay in the following manner.The electric current that flows out transistor 136 emitters flows through resistance 516 at first.Resistance 516 is connected to the binding site of transistor 143 base/emitter.Because transistor 143 and 142 is off-state at first, the base stage of transistor 142 is by resistance 517 ground connection.Along with current flowing resistance 516, this electric current also flows to the emitter of transistor 142.This causes transistor 142 conductings, and collector current provides from transistor 142 by line 31.What transistor 144 needed starts the time of carrying out, and transistor 136 and resistance 516 are opened the required time of transistor 142, cause to conducting testing circuit 20, sending on online 31 the delay of inhibit pulse.
Along with the conduction threshold of voltage drop on resistance 516 to transistor 143, transistor 143 conductings, the base drive of adjusting transistor 142.Transistor 136 offers electric current at the emitter of transistor 143, and the magnitude of current that therefore flows to resistance 517 from transistor 143 also offers the emitter of transistor 143.Along with flowing through the electric current of transistor 142, increase, the base drive of transistor 143 also increases.This causes transistor 143 to provide more electric current to resistance 517, then removes the base drive from transistor 142.
Other principles about conduction detection inhibit circuit 44 in Fig. 3 B are also shown in figure, and transistor 137 has an emitter, and this emitter is connected to the emitter of transistor 142 by resistance 515, and base stage is connected with the base stage of transistor 142.This forms a current source, the little electric current of electric current that it provides a ratio to flow through transistor 142.Levels of current arranges by the difference between transistor 137 and 142 base/emitter, is applied to resistance 515.In literary composition, will introduce in detail, within the time period of a delay, transistor 137,138,139,142 and 150 can disable transistor 136 base stage work.
The above, and the residual circuit of reference circuit 22 will be described in more detail in disconnection detection circuit 28.
Fig. 3 C, switch/regulating circuit 24:
About Fig. 3 C, the driving of switch/regulating circuit 24 of the present invention will be described now in more detail with running.Output driving circuit 46, drives loop circuit 50 and regulating circuit 48, is presented in dotted line frame.
Switch/regulating circuit 24 receives the power supply excitation on terminal 14.Switch/regulating circuit 24 online 58 receives a signal for faster from accelerating circuit 26, receives a bias voltage signal from NPN type bias circuit in Fig. 3 B on online 52.
Received in the base stage of the transistor 160 of the bias voltage signal on line 52 in driving loop circuit.The collector electrode of transistor 160 offers the transistor 157 of diode connection.Transistor 157 in the configuration of current mirror with transistor 155,156,158 are connected.
Signal for faster on line 58 is applied to the base stage of transistor 159, and pulse current of this transistor application is to the transistor 157 that drives loop circuit 50, by field effect transistor 408 and resistance 572.This pulse makes transistor 157 enter rapidly mode of operation.
The collector electrode of transistor 158 is connected to the base stage of transistor 166, to transistor 166, provides driving.It should be noted the emitter of transistor 159, it is to driving loop circuit 50 that signal for faster is provided, and the base stage that is also connected to transistor 166 is for turn-on transistor 166 rapidly.
The collector electrode of transistor 166 is connected to the base stage of the multicollector PNP transistor 169 of 46 li of output driving circuits by field effect transistor 411 and resistance 524.The electric current that flows through transistor 166 collector electrodes provides driving signal to transistor 169.The emitter of transistor 169 is connected to terminal 14, i.e. power supply, and collector electrode 169B is connected to lead-out terminal 16.
Adopt positive feedback to increase the driving signal of transistor 169.This positive feedback path comprises that the collector electrode 169A of transistor 169 is to the collector electrode/base stage of diode-connected transistor 172, base stage/the collector electrode of transistor 161, field effect transistor 408, resistance 572, base stage/the collector electrode of transistor 158, the base stage/collector electrode of transistor 166, field effect transistor 411, resistance 524, and the base stage of transistor 169.
Will describe in more detail this positive feedback now.From loop, some arbitrfary points start, and for example transistor 158, and the electric current that flows out transistor 158 offers transistor 166, and this electric current is amplified by the gain of transistor 166.Then amplifying signal is provided to the base stage of transistor 169 from the collector electrode of transistor 166.Electric current is further amplified by the gain of transistor 169.Suppose, for example the gain of transistor 166 is 40, and the gain of transistor 169 is 20, and the electric current in initial transistor 166 base stages is i, and the output current of transistor 169 will be 800i so.
When using positive feedback in the above described manner, can obtain an efficient drive arrangements.For example, output current is 1.2A, and the gain of supposing transistor 169 is 20, and the gain of transistor 166 is 40, the collector current that transistor 160 work only need to approximately 10 microamperes.By contrast, if come driving transistors 169 to obtain the output current of 1.2A by more traditional method, biasing circuit need to be under about 2mA electric current continuous service.
For the positive feedback work of stable switch/regulating circuit 24, adopt a negative feedback, this negative feedback paths is from output driving circuit 46 process regulating circuits 48 to driving loop circuit 50.More specifically, transistor 170 connects, so, along with flowing out the electric current of collector electrode 169B, increasing, it guides more electric current to enter diode-connected transistor 171.Conversely, the electric current of this increase is in the collector electrode reflection of transistor 162.Can from Fig. 3 C, see, transistor 162 connects, and draws away the base drive from transistor 166.Therefore along with flowing out the electric current of transistor 169, increase, negative feedback paths reduces the driving level of transistor 166 from transistor 170,172 and 162, thereby reduces the output current level of transistor 169.
At preferred version of the present invention, the gain of positive feedback path should be more a little bit smaller a little than the gain of negative feedback paths; For example the ratio of the gain of positive and negative feedback is 2.0:2.1.
The regulating circuit 48 of switch/regulating circuit 24 provides the voltage-regulation of switch output.By providing reference voltage can realize voltage-regulation, reference voltage is compared with the output signal on terminal 16.This reference voltage online 52 obtains from bias voltage signal.Bias voltage signal is applied to the base stage of transistor 174, and the levels of current of the collector electrode that flows through transistor 174 is set.This electric current flow through series connection field effect transistor 413, resistance 525, resistance 526 and diode-connected transistor 311.The voltage being provided by the resistance of connecting and diode, provides a reference voltage at node 17.Voltage on node 17 is applied to the base stage of transistor 170, and output voltage on terminal 16 is applied to the emitter of transistor 170.
The collector electrode of transistor 170 is connected on diode-connected transistor 171, and transistor 171 and transistor 162 form a current mirror.Conversely, the collector electrode of transistor 162 is connected to the base stage of transistor 166.Therefore, the electric current of inflow transistor 162 collector electrodes draws away the base drive of transistor 166.Therefore can see, along with the voltage differences on terminal 16 and node 17 increases, transistor 170 drives, and causes drive current away from transistor 166, thereby reduces to offer the base drive of transistor 169.This causes the voltage on terminal 16 to reduce conversely, thereby voltage-regulation is provided.
Voltage-regulation keeps transistor 169 in saturation condition, and by transistor 173, field effect transistor 412 and transistor 172 provide.As discussed above, diode-connected transistor 172 is connected to the collector electrode 169A of transistor 169.At preferred version of the present invention, collector electrode 169A provides an electric current, and this electric current is the sub-fraction that flows out collector electrode 169B electric current.Collector electrode 169A is as a current detecting terminal, and collector electrode 169B is as output.For example, the ratio of output current and induced current can be 599.5:0.5.Therefore, any curent change of output collector electrode, will proportional reaction at detected set electrode.
Along with the electric current of detected set electrode is applied to diode-connected transistor 172, transistor 173 is as a current mirror.The electric current of inflow transistor 172 collector electrodes goes out self-resistance 526.This has increased the voltage at resistance 526 two ends.Therefore, can know, flow through the electric current of transistor 169, affect on node 17 by diode 311, resistance 526 and 525 reference voltages that form.The collector electrode 169B electric current required along with load increases, the electric current demand of increase, and what be directly proportional is reflected on the electric current that flows through transistor 173.Conversely, this causes resistance 526 two ends to have a large voltage, thereby causes the reference voltage on node 17 to reduce.This causes transistor 170 conducting difficulties, thereby causes the base drive of output driving transistors 169 to reduce.Conversely, this makes collector electrode 169B be operated in larger voltage difference, and voltage difference is from the emitter of transistor 169.Therefore,, when load needs more electric current, by reducing reference voltage, make transistor 169 remain on hypersaturated state.
At preferred version of the present invention, the output impedance of switch when conducting state is approximately 1 ohm.In off-state, the invention provides one and be roughly infinitely-great output impedance, because its original electric current that just do not need to maintain.
The residual circuit of Fig. 3 switch/regulating circuit 24, is divided into conduction mode and Disconnected mode, will below further discuss in detail.
Fig. 3 D disconnection detection circuit:
About Fig. 3 D, disconnection detection circuit 28 will be described in more detail.Need to understand for the purposes of the present invention, be applied to the control signal on terminal 12, conducting wherein and off-state can be detected by the conduction detection circuit 20 of Fig. 3 A.If wish that conduction detection circuit 20 is used for detecting conducting state and off-state, transistor 117 and 119 will save.
Control signal on terminal 12 is greater than the size of reference voltage on line 37, namely, has a conducting state on terminal 12, and transistor 181 disconnects, transistor 180 conductings.Because transistor 180 is in conducting state, transistor 184 and 187 is also in conducting state.When conducting, these transistors forbid that cut-off signal offers switch/regulating circuit 24 and reference circuit 22.
As previously discussed, at Disconnected mode, disconnection detection circuit 28, provides the driving loop circuit 50 of a cut-off signal to switch/regulating circuit 24 by line 26, by line 68, provides the regulating circuit 48 of a cut-off signal to switch/regulating circuit 24.Disconnection detection circuit 28, provides reference holding circuit 42 parts of cut-off signal to reference circuit 22 by line 62.From Fig. 3 D, can find out, transistor 184 drive wires 68, and transistor 187 is controlled transistor 191 drive wires 62, controls transistor 189 drive wires 66.
When transistor 180 conductings, also conducting of transistor 184 and 187.About Fig. 3 D and Fig. 3 C, line 68, can see, when transistor 184 conductings, the transistor 165 in Fig. 3 C will be delayed.This is because of for offered the bias voltage signal of transistor 165 by transistor 156, by transistor 184, transfers to ground completely.
But, when transistor 184 disconnects, from the bias voltage signal of transistor 156, offer transistor 165, be used for driving it to enter conducting state.When transistor 165 conductings of Fig. 3 C, it coordinates with transistor 168 by field effect transistor 410, makes to export the base/emitter node electric discharge of driving transistors 169.It is to be understood that, the base/emitter node electric discharge of transistor 169 occurs, is together with during removing transistorized base drive at Disconnected mode.
Get back to Fig. 3 D, when transistor 187 conducting, transistor 189 normally disconnects.There is off-state in the control signal on terminal 12, transistor 181 conductings and transistor 180 disconnects.When transistor 180 disconnects, transistor 187 is prohibited.At this time, from line 74, flow through the electric current of transistor 187, on the contrary can driving transistors 189,190,191.
It should be noted that signal on line 74 is from the transistor 155 of Fig. 3 C.From Fig. 3 C, can see, the electric current of inflow transistor 155 is proportional to the bias voltage signal that offers transistor 166, and transistor 166 provides driving signal to transistor 169.It should be noted that line 66 is connected to the base stage of transistor 166.Therefore,, when transistor 189 conductings carry out drive wire 66, the signal providing will be proportional to the bias current that offers transistor 166 in Fig. 3 C.When transistor 189 conductings, all bias currents that conventionally should inflow transistor 166 base stages, transfer to ground on the contrary, thereby disconnect transistor 166.In order to upper type, there is off-state in the control signal detecting on terminal 12 when transistor group 180 and 181, and the base drive of transistor 169 is prohibited and the base/emitter node of transistor 169 discharges.
There is off-state in the control signal on terminal 12, transistor 180 is disconnected, thereby make transistor 187 electric discharges, and transistor 188 also receives base drive from line 74.This causes transistor 188 conductings, thereby keeps or lock transistor 181 in conducting state.
About the transistor 190 of Fig. 3 D, as can be seen from the figure, transistor 190 can be diverted to ground and signal for faster by line 58, and signal for faster is provided by the accelerating circuit 26 of Fig. 3 B, is used for driving the bias circuit 50 of Fig. 3 C.Therefore, when starting Disconnected mode, transistor 190 is switched on, and is used for preventing that any signal for faster from offering switch/regulating circuit 24, and switch/regulating circuit 24 can prevent that switch from disconnecting.
About the transistor 191 of Fig. 3 D, and the transistor 147 of Fig. 3 B, as can be seen from the figure, transistor 191 is shunted through transistor 147 by line 62.Therefore,, when transistor 191 conductings, the current mirror being formed by transistor 147 and 124 is just prohibited.As previously mentioned, the part that transistor 147,124 forms with reference to holding circuit 42, makes reference voltage circuit 36 remain on operating condition with reference to holding circuit.Therefore, in the control signal on terminal 12, off-state detected, transistor 191 is driven, makes the reference holding circuit 42 of reference circuit 22 forbid work.
About the transistor 150 in Fig. 3 B and line 64, the transistor 180 in Fig. 3 D and line 64, as can be seen from the figure, when transistor 180 conductings, the signal that offers line 64 causes transistor 150 conductings.As can be seen from Figure 3B, transistor 150 shuntings are through transistor 138.Transistor 138 and transistor 139 and 127 form a part for current mirrors.As above concise and to the point discussion, these transistors form a part for turn-off delay circuit 30 together with 144 together with transistor 136,142.
Transistor 180 disconnections as Fig. 3 D, show to detect off-state in the control signal on terminal 12, and transistor 150 is prohibited.This makes by transistor 138,139 and the 127 current mirror entrys into service that form.Transistor 127 provides base drive to transistor 128, and transistor 128 accelerates to disconnect transistor 129 conversely, and transistor 129 provides excitation to reference voltage circuit 36.More specifically, transistor 127 is linked ground by the base stage of transistor 129, thereby the collector electrode of the base stage of transistor 128 and transistor 123 is linked ground.Recall, when Disconnected mode starts, transistor 147 and 124 disconnects, and removes the base drive of transistor 123.Therefore transistor 123 disconnects at this moment.When the base stage of transistor 129, namely the base stage of transistor 128, reaches the base/emitter that any makes transistor 128, and lower than its emitter base stage of transistor 133 namely, transistor 128 conductings, remove the excitation from reference voltage circuit 36 rapidly.Recall the magnitude of current of inflow transistor 138, thereby be reflected to the magnitude of current of transistor 127, by the voltage drop on resistance 515, be set up.This electric current is relatively little, so the electric discharge of transistor 129 base stages is not instantaneous.Therefore, for some time, during this period of time, base drive removes from transistor 129, and transistor 129 disconnects.
During this period of time, the transistor 139 of Fig. 3 C, enters running, starts to remove the base drive of transistor 136.As a setting, transistor 136 driving transistorss 142, provide inhibit signal on transistor 142 online 31, are used for forbidding 20 work of conduction detection circuit.Should, after Disconnected mode starts, keep conduction detection circuit 20 in the one very short period of illegal state.This prevents that transient state and other influences from reclosing switch.Transistor 136 also provides the transistor 188,189,190 and 191 of base drive to disconnection detection circuit 28, and these transistors provide the remainder of cut-off signal to this switch.Therefore, at Disconnected mode, along with offering the cut-off signal of conduction detection circuit 20, drive and forbid driving, the various piece of this switch disconnects successively with an ordered sequence, and conduction detection circuit is finally disconnected.
The running of turn-off delay circuit 30 is relevant to the running of NPN type bias circuit 38 and positive-negative-positive bias circuit 40.From Fig. 3 B and positive-negative-positive bias circuit 40, can find out, a collector electrode of transistor 144 connects by diode-connected transistor 305, to the transistor 133 of reference voltage circuit 36, provides driving signal.As long as NPN type bias circuit 38 and 40 runnings of positive-negative-positive bias circuit, reference voltage circuit 36 will keep conducting.
Signal on line 64 makes transistor 150 invalid, from the discharge path conducting of diode-connected transistor 306 and transistor 127.Conversely, the electric current that offers transistor 133 base stages by diode-connected transistor 305 is by 128 minutes inflow places of transistor.This causes the reference voltage that offers NPN type bias circuit 38 on online 37 to reduce, thereby causes the bias voltage signal that offers positive-negative-positive bias circuit by NPN type bias circuit 38 also to reduce.Conversely, this causes transistor 146 to disconnect, thereby transistor 144 is also disconnected.Along with transistor 144 disconnects, the driving signal of the transistor 133 in reference voltage circuit 36 is reduced to zero, the same driving signal that also has transistor 136.This starts turn-off delay.
At preferred version of the present invention, total time of delay, from Disconnected mode, start to completing of turn-off delay, about ten microseconds.
Even after transistor 144 disconnects, transistor 136 remains on conducting state a period of time.This is because the time that transistor 139 discharges and spends to the base stage of transistor 136.The electric current that it should be noted that inflow transistor 139 is that the electric current that flows through transistor 138 reduces electric current later.This be because resistance 519 on the emitter of transistor 139.Electric current and parasitic capacitance that this has reduced in transistor 136 base stages, determined time of delay.Therefore, give the inhibit signal of conduction detection circuit, offer the transistorized driving signal of disconnection in disconnection detection circuit 28, at reference voltage circuit 36, after NPN type bias circuit 38 and positive-negative-positive bias circuit 40 disconnect, will keep a bit of time.
Get back to Fig. 3 D, on disconnection detection circuit 28 online 72, receive the signal for faster from accelerating circuit 26.Signal for faster on line 72 enters conducting state by diode-connected transistor 313 and resistance 527 driving transistorss 183.Conversely, electric current is drawn by diode-connected transistor 312 from the base stage of transistor 180, enters into the collector electrode of transistor 183.This causes transistor 180 conductings, and disconnection detection circuit 28 enters operating condition.
It should be noted that transistor 177 is applied to electric current a part for a series of current mirrors of collector transistor 177 composition of transistor 180 and 181 jointly, current mirror drives by the positive-negative-positive bias circuit 40 in Fig. 3 B, and connects together by line 45.When switch/regulating circuit 24 conducting for the first time of Fig. 3 C, provide in an acceleration pulse online 45.About Fig. 3 C and transistor 153 and 247, can know, from the signal for faster of accelerating circuit 26, be applied at first on line 58, be used for driving transistors 159 to enter conducting state.Online 45 and the collector electrode of transistor 159 between, for a signal path is created in initial acceleration pulse, by collector emitter and the field effect transistor 408 of transistor 153.This signal path shifts a part for signal for faster and leaves driving bias circuit 50, to make the output current of current mirror keep large peak value, current mirror forms by transistor 157 and 158, is used for keeping the interference of radio frequency away from the output of this switch.At reference circuit 22, electric current sharp wave is used as the signal for faster to PNP bias circuit 40, to make rapidly this circuit enter operating condition.
Contrary, at the Disconnected mode of switch, the signal path on line 45, is used to disconnect the various current sources that are attached thereto.More specifically, when transistor 128 conductings, be used for disconnecting reference voltage circuit 36, also to transistor 178, provide base drive.Conversely, transistor 178 makes transistor 154 conductings.A collector electrode of transistor 154 is connected to line 45.When transistor 154 conductings, it removes base drive effectively, and base drive is provided by all current sources that are connected on line 45.Therefore, the transistor 144,146 and 145 in PNP bias circuit 40 is disconnected, the transistor 175 and 177 in same disconnection detection circuit 28 in addition.
Fig. 3 E error detect circuit 32:
As previously mentioned, from the signal of error detect circuit 32, offer disconnection detection circuit 28, cause double-pole switch of the present invention to quit work.On these signals online 64, offer disconnection detection circuit 28.From Fig. 3 D, in Fig. 3 E and Fig. 3 F, can find out, error flag circuit 76 and thermal protection circuit 78 all turn round to forbid transistor 184 and 187 work in Fig. 3 D.When certain error condition is detected, the transistor 227 in Fig. 3 E, the transistor 207 in Fig. 3 F, all connects by line 64, and shunting transistor 184 and 187 base drive are to ground.When an overvoltage condition being detected, transistor 227 work.When heat is turn-offed generation, transistor 207 work.As previously mentioned, under these states, output driving circuit 46 is prohibited, and error flag is set up, and reference circuit 22 keeps conducting state.
In power supply being detected, have overvoltage condition, the transistor 227 of the error flag circuit in Fig. 3 E is switched on.This state passes through diode-connected transistor 320, Zener structure 609,610,611 and 612, and field effect transistor 416 and resistance 544,545 and 546 are detected, and these are all connected between VDD-to-VSS.When voltage exceeds the puncture voltage of Zener structure 609 to 612, when electric current flows through transistor 222, the collector electrode of transistor 222 connects to come driving transistors 227.When there is this situation, transistor 242 is also switched on, and by the electric current of line 80 absorbing crystal pipe 179 collector electrodes, makes closely current potential of line 80.
From Fig. 3 F, can find out, line 80 is connected to the base stage of transistor 230.Conversely, when transistor 230 conducting, it keeps the current mirror being formed by transistor 231 and 212 in off-state.Along with line 80 becomes earth potential, transistor 230 disconnects and transistor 231 and 212 conductings.This makes electric current flow through line 83 and enters transistor 212.From Fig. 3 B lower left corner, can find out, line 83 is connected to field effect transistor 404 and diode-connected transistor 123.Therefore line 83, as the current source that offers transistor 123, makes transistor 123 remain on conducting state, even if transistor 124 is come on line 62 to disconnect from the cut-off signal that disconnects testing circuit 28.This makes reference circuit 22 keep conducting with drive error sign, but output driving circuit 46 is disconnected.
As long as hot off state detected, line 80 also becomes earth potential by the transistor 229 in Fig. 3 F.
When hot guard mode being detected, the transistor 207 in the thermal protection circuit of Fig. 3 F is switched on.More specifically, transistor 202 and 203 forms a differential comparator group.Transistor 203 receives a voltage in its base stage, and this voltage is the sub-fraction of the reference voltage on line 37, and reference voltage is from reference voltage circuit 36.From a signal application of transistor 199, arrive the base stage of transistor 202.Transistor 199 is placed on and the position of exporting driving transistors 169 and leaning on very closely.Therefore transistor 199 has identical temperature with output driving transistors 169 substantially.Well-known in the art, transistor base/emitter voltage changes along with temperature change.The base stage of transistor 199 connects to receive the reference voltage on line 37, and its emitter is connected to ground by resistance 519.
Along with the variations in temperature of transistor 199, the voltage that offers transistor 202 base stages also changes.The temperature of transistor 199 raises, and the base/emitter of transistor 199 increases, and the voltage that offers transistor 202 base stages also increases.This makes transistor 203 conductings and transistor 202 disconnections.
As a setting, when the operating temperature of output driving transistors 169 is in acceptable level, transistor 202 conventionally will conducting and transistor 203 will disconnect conventionally.Along with transistor 202 conductings, transistor 206 is also conducting conventionally, thereby keeps transistor 229,207 and 234 in off-state.When transistor 202 disconnects and transistor 203 conductings, transistor 206 is prohibited, thereby makes transistor 229,207 and 234 by current source transistor 204 driving work.
Get back to Fig. 3 E, as long as the mistake of detecting, error detect circuit 32 also provides an error flag.This error flag provides by transistor 225.A low level shows that mistake occurs.The signal driver that transistor 225 is provided by transistor 223.Transistor 223 is parts of current-mirror structure, and transistor 239 and the transistor in 214, Fig. 3 F 204,151 of this current-mirror structure in Fig. 3 E forms.
Work as switch conduction, by transistor 223, offered the driving signal steering transistor 224 of transistor 225.Transistor 224 remains on conducting state by base drive, and this base drive is provided by transistor 214.Alternately, in the control signal on terminal 12, off-state detected, the transistor 226 in Fig. 3 E and transistor 232 conductings in Fig. 3 B, from transistor 225 shuntings.In this case, transistor 226 is by the current drives on line 82, and this electric current is from the transistor 181 in Fig. 3 D.Transistor 232 connects all base stages of transistor 225 by line 94, and at the Disconnected mode of turn-off delay circuit 30, transistor 232 is switched on.
Therefore, if error flag occur on online 98, transistor 224 and 226 all should be in off-state.
As discussed above, error flag circuit 76 also detects, and output 16 is to whether short circuit between energy supply end 14, and output 16 is whether short circuit to ground, and whether output 16 lacks load.
For detection of output 16, to the circuit of short circuit whether between power supply terminal 14, can in Fig. 3 C and Fig. 3 E, find.Transistor 233 in Fig. 3 C connects so that its emitter is connected with terminal 16, and its base stage is connected to the collector electrode/base stage of diode-connected transistor 311.In this way, if output 16 is shorted to power supply terminal 14, electric current will flow out the collector electrode of transistor 233 so.A collector electrode of transistor 233 is connected to the base stage of transistor 129, therefore, can lock reference circuit in conducting state until remove short circuit.Transistor 233 another collector electrodes are connected to the base stage of the transistor 238 in Fig. 3 E by line 88.When the base stage of electric current inflow transistor 238, transistor 238 is switched on, and is used for disconnecting transistor 226.During transistor 180 conducting in Fig. 3 D, transistor 237 connects makes base drive away from transistor 238.While there is no error condition or off-state in the control signal on terminal 12, transistor 180 will be in conducting state.As mentioned above, when transistor 226 is disconnected, the error flag on line 98 can be set to misdirection.
Circuit for detection of limiting condition can be found in Fig. 3 E.Transistor 209 and 210 their collector electrode and base stages link together, and share the electric current from transistor 208.The bias voltage signal that transistor 208 receives from NPN bias circuit in Fig. 3 C.The emitter of transistor 209 is connected to output 16 by diode-connected transistor 319.Like this, the voltage on the emitter of transistor 209, the voltage of the few diode of voltage on specific output end 16.The emitter of transistor 210 is connected with the emitter of transistor 211.The collector electrode of transistor 211 is connected to the base stage of transistor 213, and the base stage of transistor 211 is connected to the node 17 in Fig. 3 C by line 88 '.Voltage on node 17 serves as a reference to regulating circuit 48.Electric current in switch/regulating circuit 24 regulates, and is that the voltage by adjusting on node 17 is realized, and the voltage on node 17 regulates according to the electric current that flows out driving transistors 169.
Therefore can say, if the voltage on terminal 16, lower than the voltage on node 17, limited current state is so occurring.In other words, regulating circuit 48 can not be adjusted the driving that offers output driving transistors 169, is for the output voltage on terminal 16 is remained on the voltage on node 17.From Fig. 3 E, can know, when the voltage on terminal 16 is greater than the voltage on node 17, conventionally transistor 209 can be in conducting state and transistor 210 in off-state.Transistor 211 will be disconnected in this case.But the voltage on terminal 16 is during lower than voltage on node 17, and transistor 209 disconnects and transistor 210 conductings.Now, along with electric current can flow through transistor 210, transistor 211 will conducting, thereby drives multicollector transistor 213 to enter conducting state.
A collector electrode of transistor 213 provides driving signal to transistor 217.Conversely, during transistor 217 conducting, 224 work of its disable transistor.During transistor 224 conducting, make current drives away from transistor 225, transistor 225 is error flag drivers.Therefore,, by disconnecting transistor 224, can produce error flag.
In Fig. 3 C and Fig. 3 E, can find for detection of loaded circuit whether on terminal 16.As mentioned above, in output driving transistors 169, the electric current that flows out collector electrode 169A is proportional to the electric current that offers output 16 from collector electrode 169B.Collector electrode 169A is connected to a current mirror, and this current mirror is comprised of transistor 172,173 and transistor 216.Transistor 216 is connected to the base stage of transistor 172 by line 90.Along with offering the electric current of terminal 16, go to zero, the electric current being provided by collector electrode 169A also can go to zero.This electric current reducing is reflected on the electric current that flows through the collector electrode of transistor 216 in Fig. 3 E.Collector current driving transistors 215 work of transistor 216, transistor 215 provides electric current to current mirror transistor 218 and 219 conversely.
When terminal 16 lacks load, collector electrode 169B or 169A will not have outflow of bus current.Conversely, this makes transistor 216, transistor 215, and transistor 218 and transistor 219 disconnect.The electric current that this makes originally to flow to transistor 219 collector electrodes, flows to the base stage of transistor 220.This makes transistor 220 conductings and disable transistor 224 work.As mentioned above, when transistor 224 is prohibited, and not at Disconnected mode, error flag will occur on online 98 so.
The clause of the illustrative clause of term used herein and expression formula rather than restriction, use these terms and expression formula be not intended to limit claim of the present invention or shown in the scope of scheme.
Claims (9)
1. a switch that maintains zero current, it is characterized in that: the solid-state device to control signal sensitivity, by power supply, powered to the load, load comprises: checkout gear and an output, this checkout gear has the input of a reception control signal, detects conducting state in control signal, and this output produces a pumping signal, described checkout gear comprises the circuit of carrying out above-mentioned measuring ability, and this circuit is driven separately by control signal at first; Be connected to the power supply device between power supply and load, there is an input, this input is responsive to pumping signal, this pumping signal provides driving to load, described power supply device comprises, for responsing excitation signal, and the device of conversion from off-state to conducting state, in off-state, described power supply device does not need quiescent bias current.
2. a kind of switch that maintains zero current according to claim 1, it is characterized in that: power supply device wherein further comprises: reference unit and control device, this reference unit has an input to pumping signal sensitivity, comprises the circuit that reference voltage signal can be effectively provided; Control device is responsive to reference voltage signal, is connected to power supply and load, can control the excitation of supply load; There is one lasting period in pumping signal, after during this period of time, pumping signal is removed, and further, reference unit comprises: be connected to the exciting bank of power supply, can effectively produce reference voltage signal; First device to pumping signal sensitivity, within the duration of pumping signal, this pumping signal is used for driving generation reference voltage signal; And holdout device, this holdout device has one to the input of reference voltage signal sensitivity and an output that is connected to the first exciting bank, after pumping signal removes, maintains reference voltage signal.
3. a kind of switch that maintains zero current according to claim 2, is characterized in that: control device comprises, be connected to and load between drive unit, for load provides excitation, enter operating condition; To the second device of reference voltage signal sensitivity, the second device is used for encouraging drive unit; Be connected to drive unit and the feedback device to the operating condition sensitivity of drive unit, maintain drive unit in operating condition.
4. a kind of switch that maintains zero current according to claim 3, is characterized in that: described drive unit comprises, a device that is connected to the second exciting bank produces and drives signal; To driving the output driving device of signal sensitivity, to load, provide excitation; Feedback device comprises, be connected to output driving device, to driving signal generation device that the device of positive feedback signal is provided, further, driving signal generation device comprises, responsive to positive feedback signal, and by the device of its amplification, this device is the positive feedback signal after amplifying, as the driving signal of output driving device.
5. a kind of switch that maintains zero current according to claim 4, is characterized in that: feedback device further comprises, is connected to output driving device and drives between signal generation device, and the device of a negative-feedback signal is provided to output driving device.
6. a kind of switch that maintains zero current according to claim 4, it is characterized in that: reference unit and drive unit have intrinsic start-up time, further, the the one the second exciting banks inject an instantaneous signal for faster to reference unit and drive unit respectively, to such an extent as to, at one section, within the time of intrinsic start-up time, reference unit and drive unit can enter running.
7. a kind of switch that maintains zero current according to claim 4, is characterized in that: described control signal comprises the state of a disconnection, further comprises, responsive to off-state, for disconnecting the device of reference unit and adjusting device.
8. a kind of switch that maintains zero current according to claim 7, is characterized in that: disconnecting apparatus comprises, reception control signal, and the device to off-state sensitivity, for generation of cut-off signal; Be connected to holdout device and feedback device, the device to cut-off signal sensitivity, cut-off signal is used for forbidding holdout device and feedback device work; Solid-state device further comprises, is connected to the device of reference signal generation device, in the scheduled time after holdout device is prohibited, maintains reference unit in operating condition; Be connected to drive unit the device to cut-off signal sensitivity, cut-off signal is used for forbidding drive unit work; In solid-state device work, while breaking down state, provide the device of an error flag; Further comprise, when there is overvoltage malfunction, the device to overvoltage malfunction sensitivity, this device is being forbidden in the solid-state device of drive unit work; When there is overheating fault state, the device to overheating fault state sensitivity, it is in the solid-state device the inside of forbidding drive unit work.
9. a kind of switch that maintains zero current according to claim 1, it is characterized in that: the monolithic double-pole switch to control signal sensitivity, by power supply, to load, provide excitation, this switch comprises: checkout gear, this device has input and the output for generation of signal for faster of a reception control signal, input is for detecting the existence of conducting state in control signal, described checkout gear comprises the circuit of carrying out above-mentioned measuring ability, and this circuit is driven separately by control signal at first; Be connected to the power supply device between power supply and load, there is an input, this input is responsive to signal for faster, to load, provides driving, and described power supply device comprises, in order to respond signal for faster, the device of conversion from off-state to conducting state, in off-state, described power supply device does not need to maintain electric current, described power supply device comprises: for generation of the driving signalling that drives signal, have an amplitude controlled output; Output device to described driving signal sensitivity, for providing excitation to load; Be connected to output device and drive the feedback device between signalling, for providing positive feedback to driving signalling, positive feedback signal makes to drive the amplitude of signal to increase; Be connected to power supply device, and the inhibiting apparatus to the off-state sensitivity in control signal, for forbidding power supply device work, described inhibiting apparatus comprises: for disconnecting the electric discharge device of output device; When output device is disconnected, to the turn-off delay device of electric discharge device energy supply; For responsive control signal, in solid-state device, by power supply, to the method for load energy supply, comprise step: in control signal, detect the existence of conducting state and produce a pumping signal, comprise, only from control signal, detect conducting state, the initial step that obtains excitation; Responsing excitation signal, to load energy supply, when pumping signal is provided, is used power supply device, and this device can be changed to conducting state from off-state, and wherein said power supply device does not need quiescent bias current in off-state; Energy supply step described in above-mentioned steps comprises the following steps: that response, from the pumping signal of reference unit, provides reference signal; Response reference signal, controls the application of power supply to load; Pumping signal in said method has the predetermined duration, provides the step of reference signal further to comprise the following steps: to set reference unit and can encourage from off-state to operating condition; Within the duration of pumping signal, drive reference unit, responsing excitation signal; By the holdout device to reference signal sensitivity, maintain reference unit in operating condition; Control step described in said method comprises the following steps: that, by being connected to the drive unit between power supply and load, to load energy supply, drive unit produces controlled output level, and can encourage from off-state to operating condition; By the second device to reference signal sensitivity, drive unit work; By being connected to drive unit and the feedback device to the operating condition sensitivity of drive unit, improve the output level of drive unit; Reference signal described in said method produces step and comprises the following steps: by reference to device for generating voltage, generates a reference voltage; Offset signal response reference voltage is provided; Actuation step wherein comprises, within the duration of pumping signal, to reference voltage generating device energy supply; Further, the step that produces holdout device comprises, maintaining signal application to the first exciting bank, so the first exciting bank is still effective when lacking pumping signal; Drive unit described in said method comprises the driving bias unit that is connected to the second exciting bank, for generation of one, drive offset signal, with to driving the output driving device of offset signal sensitivity to be used for to load energy supply, the step that maintains wherein comprises, a positive feedback signal is applied to driving bias unit, so drive bias unit still effective, have nothing to do with the second exciting bank and improved the amplitude that drives offset signal; Power supply device described in said method has an intrinsic start-up time, and further, energy supply step wherein comprises instantaneous signal for faster is applied to power supply device, thus at one section within the time of intrinsic start-up time, power supply device can enter running.
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| CN113009862A (en) * | 2021-02-25 | 2021-06-22 | 成都科创时空科技有限公司 | Remote controller based on loRa |
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| JPH07212213A (en) * | 1993-11-09 | 1995-08-11 | Texas Instr Inc <Ti> | Low-power output buffer |
| CN100553132C (en) * | 2004-02-18 | 2009-10-21 | 株式会社理光 | Supply unit |
| CN102427359A (en) * | 2011-12-06 | 2012-04-25 | 四川和芯微电子股份有限公司 | Interpolation circuit and interpolation system |
| CN102957303A (en) * | 2012-12-10 | 2013-03-06 | 成都芯源系统有限公司 | Control circuit, switch converter and control method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113009862A (en) * | 2021-02-25 | 2021-06-22 | 成都科创时空科技有限公司 | Remote controller based on loRa |
| CN113009862B (en) * | 2021-02-25 | 2023-07-21 | 成都科创时空科技有限公司 | Remote controller based on loRa |
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Application publication date: 20140402 |