GB2025180A - Transistor electronic switching circuits - Google Patents

Transistor electronic switching circuits Download PDF

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Publication number
GB2025180A
GB2025180A GB7829068A GB7829068A GB2025180A GB 2025180 A GB2025180 A GB 2025180A GB 7829068 A GB7829068 A GB 7829068A GB 7829068 A GB7829068 A GB 7829068A GB 2025180 A GB2025180 A GB 2025180A
Authority
GB
United Kingdom
Prior art keywords
transistor
pair
base
darlington
electronic switching
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB7829068A
Other versions
GB2025180B (en
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB7829068A priority Critical patent/GB2025180B/en
Publication of GB2025180A publication Critical patent/GB2025180A/en
Application granted granted Critical
Publication of GB2025180B publication Critical patent/GB2025180B/en
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
    • H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body
    • H01L27/08—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind
    • H01L27/082—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind including bipolar components only
    • H01L27/0823—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind including bipolar components only including vertical bipolar transistors only
    • H01L27/0825—Combination of vertical direct transistors of the same conductivity type having different characteristics,(e.g. Darlington transistors)
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
    • F02P3/00—Other installations
    • F02P3/02—Other installations having inductive energy storage, e.g. arrangements of induction coils
    • F02P3/04—Layout of circuits
    • F02P3/0407—Opening or closing the primary coil circuit with electronic switching means
    • F02P3/0435—Opening or closing the primary coil circuit with electronic switching means with semiconductor devices
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/04—Modifications for accelerating switching
    • H03K17/042—Modifications for accelerating switching by feedback from the output circuit to the control circuit
    • H03K17/04213—Modifications for accelerating switching by feedback from the output circuit to the control circuit in bipolar transistor switches

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Electronic Switches (AREA)

Abstract

A single chip Darlington transistor pair device TR1, TR2 has a fourth contact effected to the base of the output transistor of the pair. This permits independent current control of the two transistors. A switching circuit including such a device is shown wherein feedback to the fourth contact reduces the effective storage time. <IMAGE>

Description

SPECIFICATION Improvements in or relating to electronic switching circuits This invention relates to semiconductor devices and in particular to a modified Darlington pair device and to switching circuits employing such a device.
Electronic switching circuits, such as are employed e.g. in motor vehicle ignition systems, frequently use a Darlington transistor pair as the output device. Such devices have three terminals, a input terminal contacting the base of the input transistor, and output terminals contacting the emitter of the output transistor and the collectors of both transistors. Conventionally such devices are switched on by the application of a control current to the input terminal and are switched off by discontinuing that current. With such an arrangement it is difficult to switch of quickly and at the same time to control the switch off time.
The object of the invention is to minimise or to overcome this disadvantage.
According to one aspect of the invention there is provided a single chip Darlington transistor pair device in which external contacts is effected to the base of each transistor of the pair.
According to another aspect of the invention there is provided an electronic switching circuit, including an input trigger stage and an output switching stage, in which the output stage includes a Darlington transistor pair device in which external contact is effected to the base of each transistor of the pair, a feedback loop being provided between the collector and base of the output transistor of the pair.
Figure 1 is a circuit diagram of the Darlington pair four terminal device.
Figure 2 shows a switching circuit employing the device of Fig. 1, and Figure 3 shows current and voltage waveforms across an inductor coupled to the output of the circuit of Fig. 2.
Referring to Fig. 1 the Darlington pair single chip device includes two transistors TR 1 and TR2. To effect external control of the device contact is made to the base metallisation of transistor T2, this contact being brought out to a fourth terminal 11 on the device package. In use, the device is operated by a control current applied to the base terminal 12 of the input transistor TR1, this current switching on both transistors. When the control current is switched off the input transistor TR1 turns off. In this condition independent control of the output transistor TR2 can be effected by the application of a current via the terminal 11.
Referring now to Fig. 2 the circuit shown, which may for example be employed as an ignition circuit for a motor vehicle, comprises a trigger stage including a conventional three terminal Darlington pair TR3, and an output stage including a four terminal Darlington pair device of the type shown in Fig. 1. An input to the trigger stage is provided e.g. via a phototransistor TR4 and LED D1 arrangement.
When the first Darlington pair is in its 'on' condition current is supplied to the input 12 of the output Darlington pair which is thus held 'on' and in this condition operates in the conventional manner.
When the trigger stage is switched off the output transistor of the Darlington pair TR3 becomes conductive and removes base charge from transistor TR1. After a period determined by the storage time of transistor TR2 that transistor turns off causing inductor L1 to induce a corresponding positive back E.M.F.
at the collector of TR2. This increasing positive going voltage causes base current to be passed by TR2 via capacitor C1 thus causing that transistor to become partially conductive.
This negative feedback limits the rate of the rise of voltage across the inductor. Zener diode ZD1 protects the arrangement against excessive voltages and in some applications may be omitted.
As shown in Fig. 3 as the current, after a delay corresponding to the storage time of TR2, falls, the inductor voltage rises to a maximum value V max at which level the voltage is clamped by the negative feedback through capacitor C1. When the inductor current has fallen substantially to zero the inductor voltage then falls away, a slight oscillation being caused by the small self capacitance of the inductor.
In other applications the device can be used in the following mode.
With a control current applied to the base of TOR 1 such that the device is turned on, a further control current can be applied via the fourth terminal 11 to turn the transistor TR2 on, off, or partially on.

Claims (7)

1. A single chip Darlington pair transistor device in which external contact is effected to the base of each transistor of the pair.
2. A single chip Darlington pair transistor device substantially as described herein with reference to Fig. 1 of the accompanying draw nags.
3. An electronic switching circuit, including an input trigger stage and an output switching stage, in which the output stage includes a Darlington transistor pair device in which external contact is effected to the base of each transistor of the pair, a feedback loop being provided between the collector and base of the output transistor of the pair.
4. A circuit as claimed in claim 3, and in which said feedback loop includes a capacitor.
5. An electronic switching circuit, inciuding a Darlington transistor pair device, and means for providing current contact to the base of each transistor of the pair thereby providing independent control of each transistor.
6. An electronic switching circuit substantially as described herein with reference to the accompanying drawings.
7. A motor vehicle spark ignition system provided with a circuit as claimed in any one of claims 3 to 7.
GB7829068A 1978-07-06 1978-07-06 Transistor electronicswitching circuits Expired GB2025180B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB7829068A GB2025180B (en) 1978-07-06 1978-07-06 Transistor electronicswitching circuits

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB7829068A GB2025180B (en) 1978-07-06 1978-07-06 Transistor electronicswitching circuits

Publications (2)

Publication Number Publication Date
GB2025180A true GB2025180A (en) 1980-01-16
GB2025180B GB2025180B (en) 1982-08-25

Family

ID=10498289

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7829068A Expired GB2025180B (en) 1978-07-06 1978-07-06 Transistor electronicswitching circuits

Country Status (1)

Country Link
GB (1) GB2025180B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1982004509A1 (en) * 1981-06-15 1982-12-23 Michel Hartmut Darlington transistor circuit
US4380795A (en) * 1981-03-24 1983-04-19 The United States Of America As Represented By The United States Department Of Energy Base drive circuit for a four-terminal power Darlington
DE3431676A1 (en) * 1984-08-29 1986-03-13 Robert Bosch Gmbh, 7000 Stuttgart INTEGRATED POWER AMPLIFIER

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4380795A (en) * 1981-03-24 1983-04-19 The United States Of America As Represented By The United States Department Of Energy Base drive circuit for a four-terminal power Darlington
WO1982004509A1 (en) * 1981-06-15 1982-12-23 Michel Hartmut Darlington transistor circuit
US4539492A (en) * 1981-06-15 1985-09-03 Robert Bosch Gmbh Darlington transistor circuit
DE3431676A1 (en) * 1984-08-29 1986-03-13 Robert Bosch Gmbh, 7000 Stuttgart INTEGRATED POWER AMPLIFIER

Also Published As

Publication number Publication date
GB2025180B (en) 1982-08-25

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Legal Events

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PCNP Patent ceased through non-payment of renewal fee