EP0238283A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
High voltage detecting circuit
Assignee: Fujitsu Ltd
•
Filing: 1987-03-16
•
Granted: —
•
Expires: 2007-03-16
Abstract
Abstract A high voltage detecting circuit included in a semiconductor device has a terminal (2) for generating a control signal to start a specific operating mode of the semiconductor device when a potential of a specific mode signal higher by a predetermined value than a normal input voltage having a predetermined range is applied to the terminals (2). The high voltage detecting circuit includes level shift means (4) connected between a blocking transistor (Q3) and a discrimination circuit (5) to lower the potential of the output end by a level shifted value from the potential of the input end. The level shift means (4) prevents the high voltage detecting circuit generating a control signal in error even if the semiconductor device is switched ON and a power line potential (Vcc) of the device is gradually increased while a normal mode signal of the normal input voltage is continuously applied to its terminal (2).
Inventors
- 👤 Hiromi Kawashima
- 👤 Atsushi Takeuchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 16:04
CPC Classifications
G; G01; G01R; G01R19/00; H; H03; H03K; H03K17/00; H03K17/22; H03K17/223; G01R19/165; G01R19/16504; G01R19/16519; G01R31/00; G01R31/28; G01R31/317; G01R31/31701; H03K5/00; H03K5/153
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
439 words
A high voltage detecting circuit included in a semiconductor device having terminals (2), for generating a control signal to start a specific operating mode of the semiconductor device when the potential of a specific mode signal higher by a predetermined value than a normal input voltage having a predetermined range is applied to at least one of the terminals (2) of the semiconductor device, the high voltage detecting circuit comprising: a first power supply means (Vcc) for a high potential; a second power supply means (GND) for a low potential; a blocking transistor (3), having a control electrode (S) and two other electrodes (G,D), the control electrode (S) being coupled to the at least one of the terminals (2) and, one (G) of the two other electrodes (G, D) being connected to the first power supply means (Vcc), the blocking transistor (3) switching ON when the potential of the control electrode (S) is higher by the threshold voltage of the blocking transistor (3) than the potential of the one (G) of the two other electrodes (G, D); and a discrimination circuit (5), having a first end and a second end, the first end of the discrimination circuit being coupled to the other (D) of the two other electrodes of the blocking transistor (3) for outputting the control signal from the second end of the discrimination circuit (5) when the potential of the first end of the discrimination circuit is higher than a threshold voltage of the discrimination circuit (5) by virtue of the blocking transistor (3) being turned ON, characterised in that the detecting circuit also Includes level shift means (4) having an input end and an output end, the input end being connected to the other (D) of the two other electrodes (GD) of the blocking transistor (3), the level shift means (4) obtaining a potential at the output end lower by a level shifted value than the potential at its input end; and, resistor means (6), having a first end and a second end, the first end being connected to the output end of the level shift means (4) and the second end being connected to the second power supply means (GND), the first end of the discrimination circuit (5) being connected to the output end of the level shift means (4) and to the first end of the resistor means (6) ; the resistor means (6) keeping the potential of the first end at the low potential of the second power supply means (GND) when the potential of the at least one of the terminals (2) is within the predetermined range of the normal input voltage.
Claim 2
Dependent Claim
439 words
A high voltage detecting circuit included in a semiconductor device having terminals (2), for generating a control signal to start a specific operating mode of the semiconductor device when the potential of a specific mode signal higher by a predetermined value than a normal input voltage having a predetermined range is applied to at least one of the terminals (2) of the semiconductor device, the high voltage detecting circuit comprising: a first power supply means (Vcc) for a high potential; a second power supply means (GND) for a low potential; a blocking transistor (3), having a control electrode (S) and two other electrodes (G,D), the control electrode (S) being coupled to the at least one of the terminals (2) and, one (G) of the two other electrodes (G, D) being connected to the first power supply means (Vcc), the blocking transistor (3) switching ON when the potential of the control electrode (S) is higher by the threshold voltage of the blocking transistor (3) than the potential of the one (G) of the two other electrodes (G, D); and a discrimination circuit (5), having a first end and a second end, the first end of the discrimination circuit being coupled to the other (D) of the two other electrodes of the blocking transistor (3) for outputting the control signal from the second end of the discrimination circuit (5) when the potential of the first end of the discrimination circuit is higher than a threshold voltage of the discrimination circuit (5) by virtue of the blocking transistor (3) being turned ON, characterised in that the detecting circuit also Includes level shift means (4) having an input end and an output end, the input end being connected to the other (D) of the two other electrodes (GD) of the blocking transistor (3), the level shift means (4) obtaining a potential at the output end lower by a level shifted value than the potential at its input end; and, resistor means (6), having a first end and a second end, the first end being connected to the output end of the level shift means (4) and the second end being connected to the second power supply means (GND), the first end of the discrimination circuit (5) being connected to the output end of the level shift means (4) and to the first end of the resistor means (6) ; the resistor means (6) keeping the potential of the first end at the low potential of the second power supply means (GND) when the potential of the at least one of the terminals (2) is within the predetermined range of the normal input voltage.
Claim 3
Dependent Claim
96 words
A high voltage detecting circuit according to claim 1, wherein the level shift means (4) comprises: at least one MIS transistor (Q41) having a control electrode (G) and two other electrodes (D5), the control electrode (G) and one (D) of the two other electrodes (D,S) being connected to the input end of the level shift means (4) and the other (S) of the two other electrodes (S,D) being coupled to the first end of the resistor means (6), the level shifted value being determined by the threshold voltage of the at least one MIS transistor (Q41).
Claim 4
Dependent Claim
88 words
A high voltage detecting circuit according to claim 1 or 2, wherein the resistor means (6) comprises: a depletion type MIS transistor (Q6) having a control electrode (G) and two other electrodes (G,S), the control electrode (g) being connected to one (S) of the two other electrodes (SD) and to the second power supply means (GND) and the other (D) of the two other electrodes (SD) being connected to the output end of the level shift means (4) and to the first end of the discrimination circuit (5).
Claim 5
Dependent Claim
105 words
A high voltage detecting circuit according to any one of the preceding claims, further comprising: a leakage current cutting off transistor (Q1) having a control electrode (G) and two other electrodes (SD), the control electrode (G) being connected to one (D) of the two other electrodes (S,D) and to the one (S) of the two other electrodes (SD) of the blocking transistor (3), the other (s) of the two other (S,D) electrodes of the leakage current cutting off transistor (Q1) being connected to the at least one of the terminals (2) for keeping a leakage current under a predetermined standard current of the semiconductor device.
Claim 6
Dependent Claim
373 words
A high voltage detecting circuit included in a semiconductor device having terminals, for generating a control signal in order to start a specific mode of said semiconductor device when a potential of a specific mode signal higher by a predetermined value than a normal input voltage having a predetermined range is applied to at least one of said terminals of said semiconductor device, said high voltage detecting circuit comprising: a first power supply means for a high potential; a second power supply means for a low potential; a blocking transistor, having a control electrode and two other electrodes, said control electrode being operatively connected to said at least one of said terminals of said semiconductor device and, one of said two other electrodes being operatively connected to said first power supply means, for switching ON said blocking transistor when a potential of said control electrode is higher by a threshold voltage of said blocking transistor than a potential of said one of said two other electrodes; a level shift means having an input end and an output end, said input end being operatively connected to said other of said two other electrodes of said blocking transistor, for obtaining a potential of said output end lower by a level shift value than a potential of said input end; a resistor means, having a first end and a second end, said first end being operatively connected to said output end of said level shift means and said second end being operatively connected to said second power supply means, for keeping the potential of said first end at the low potential of said second power supply means when a potential of said at least one of said terminals of said semiconductor device is within said predetermined range of said normal input voltage; and a discrimination circuit, having a first end and a second send, said first end of said discrimination circuit being operatively connected to said output end of said level shift means and to said first end of said resistor means, for outputting said control signal to said second end of said discrimination circuit when a potential of said first end of said discrimination circuit is higher than a threshold voltage of said discrimination circuit.
Claim 7
Dependent Claim
373 words
A high voltage detecting circuit included in a semiconductor device having terminals, for generating a control signal in order to start a specific mode of said semiconductor device when a potential of a specific mode signal higher by a predetermined value than a normal input voltage having a predetermined range is applied to at least one of said terminals of said semiconductor device, said high voltage detecting circuit comprising: a first power supply means for a high potential; a second power supply means for a low potential; a blocking transistor, having a control electrode and two other electrodes, said control electrode being operatively connected to said at least one of said terminals of said semiconductor device and, one of said two other electrodes being operatively connected to said first power supply means, for switching ON said blocking transistor when a potential of said control electrode is higher by a threshold voltage of said blocking transistor than a potential of said one of said two other electrodes; a level shift means having an input end and an output end, said input end being operatively connected to said other of said two other electrodes of said blocking transistor, for obtaining a potential of said output end lower by a level shift value than a potential of said input end; a resistor means, having a first end and a second end, said first end being operatively connected to said output end of said level shift means and said second end being operatively connected to said second power supply means, for keeping the potential of said first end at the low potential of said second power supply means when a potential of said at least one of said terminals of said semiconductor device is within said predetermined range of said normal input voltage; and a discrimination circuit, having a first end and a second send, said first end of said discrimination circuit being operatively connected to said output end of said level shift means and to said first end of said resistor means, for outputting said control signal to said second end of said discrimination circuit when a potential of said first end of said discrimination circuit is higher than a threshold voltage of said discrimination circuit.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.