Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
169 words
A protected Darlington transistor arrangement comprising: first (2) and second (4) bipolar transistors each having a base, a collector and an emitter, the base of the first transistor being coupled to the base (B) of the Darlington transistor, the collectors of the first and second transistors being coupled to the collector (C) of the Darlington transistor, the emitter of the first transistor being coupled to the base of the second transistor, and the emitter of the second transistor being coupled to the emitter (E) of the Darlington transistor; and a third bipolar transistor (6) having a base, a collector coupled to the collector (C) of the Darlington transistor, and an emitter, wherein the Darlington transistor arrangement further comprises: a Zener diode (8) coupled between the collector (C) of the Darlington transistor and the base of the third transistor, the base of the third transistor being coupled to the emitter of the second transistor, and the emitter of the third transistor being coupled to the base of the second transistor.
Claim 2
Dependent Claim
169 words
A protected Darlington transistor arrangement comprising: first (2) and second (4) bipolar transistors each having a base, a collector and an emitter, the base of the first transistor being coupled to the base (B) of the Darlington transistor, the collectors of the first and second transistors being coupled to the collector (C) of the Darlington transistor, the emitter of the first transistor being coupled to the base of the second transistor, and the emitter of the second transistor being coupled to the emitter (E) of the Darlington transistor; and a third bipolar transistor (6) having a base, a collector coupled to the collector (C) of the Darlington transistor, and an emitter, wherein the Darlington transistor arrangement further comprises: a Zener diode (8) coupled between the collector (C) of the Darlington transistor and the base of the third transistor, the base of the third transistor being coupled to the emitter of the second transistor, and the emitter of the third transistor being coupled to the base of the second transistor.
Claim 3
Dependent Claim
31 words
A Darlington transistor arrangement according to claim 1 wherein the base of the third transistor (6) is coupled to the emitter of the second transistor (4) via a first resistor (12).
Claim 4
Dependent Claim
31 words
A Darlington transistor arrangement according to claim 1 or 2 wherein the emitter of the first transistor is coupled to the emitter of the second transistor via the first resistor (12).
Claim 5
Dependent Claim
33 words
A Darlington transistor arrangement according to claim 1, 2 or 3 wherein the emitter of the first transistor (2) is coupled to the base of the first transistor via a second resistor (10).
Claim 6
Dependent Claim
27 words
A Darlington transistor arrangement according to claim 2 wherein the base of the third transistor (6) is coupled to the first resistor via a third resistor (15).
Claim 7
Dependent Claim
28 words
A Darlington transistor arrangement according to any preceding claim wherein the Zener diode (8) is coupled to the base of the third transistor via a fourth resistor (14).
Claim 8
Dependent Claim
28 words
A Darlington transistor arrangement according to any preceding claim further comprising a protection diode (16) coupled between the collector (C) and the emitter (E) of the Darlington transistor.
Claim 9
Dependent Claim
26 words
A Darlington transistor arrangement according to any preceding claim wherein the Zener diode is formed by a lateral pinch of layers of p+ and n+ conductivity.
Claim 10
Dependent Claim
19 words
A Darlington transistor arrangement according to any preceding claim wherein the first, second and third transistors are npn transistors.
Claim 11
Dependent Claim
15 words
A Darlington transistor arrangement according to claim 1 or 2 fabricated in integrated circuit form.