EP0075915A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Logic circuit operable by a single power voltage
Assignee: Toshiba Corp
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Filing: 1982-09-27
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Granted: —
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Expires: 2002-09-27
Abstract
Abstract In a logic circuit according to the present invention, a plurality of logic elements (40, 42, 44, 46) respectively having at least one depletion-mode switching FET (10,12,14,72,74) are connected in cascade. The source electrodes of the switching FETs (10, 12,13,72,74) are maintained at a voltage higher by a predetermined voltage than the ground potential by the Schottky diode (58) and connected commonly to each other. The switching FETs (10,12,14,72,74) are connected at the drain electrodes through active loads (50, 52, 54, 76) to a power source terminal (28) supplied with one type of external DC power source voltage (+ V). The drain potential of the switching FETs (10, 12, 14) is level-shifted to a predetermined voltage higher than the gate potential of the FETs (12, 14, 72, 74) in the next stage. The FETs (62, 66, 70, 80) are provided between the diodes (60, 64, 68, 78) and the ground to prevent the variation in the level shift voltage.
Inventors
- 👤 Shoichi Shimizu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 21:14
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/02; H03K19/08; H03K19/094; H03K19/0952
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
359 words
A circuit for performing a predetermined logic function, having a plurality of logic elements (40, 42, 44, 46, 150, 152, 154, 156, 158, 240, 242) each of which includes at least one switching transistor (10, 12, 14, 72, 74, 160, 162, 176, 178, 180, 182, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) and which are connected in cascade with each other, characterized in that said switching transistors included in said logic elements (40, 42, 44, 46, 150, 152, 154, 156, 158, 240, 242) are depletion-mode field effect transistors (10, 12, 14, 72, 74, 160, 162, 176, 178, 180, 182, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) having source electrodes commonly connected to each other and drain electrodes connected to a first terminal (28, 221, 270, 324) which is connected to an external power source (220) and which is supplied with a first voltage (+ V) higher than a second voltage at a second terminal (19, 222, 277, 331) connected to the external power source (220), and that said circuit comprises voltage level-controlling means connected between the commonly connected source electrodes of said switching field effect transistors (10, 12, 14, 72, 74, 160, 162, 176, 178, 180, 182, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) and said second terminal for maintaining the source electrodes at a predetermined third voltage (Vss) lower than the first voltage (+ V) and higher than the second voltage, and level-shifting means (32, 34, 36, 60, 64, 68, 78, 102, 104, 106, 108, 114, 116, 118, 120, 132, 134, 136, 138, 168, 192, 194, 196, 198, 256, 266, 326, 348) for level-shifting the voltage at the drain electrode of one switching field effect transistor (10, 12, 14, 160, 162, 176, 178, 180, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) included in each of said logic elements (40, 42, 44, 46, 150, 152, 154, 156, 158, 240, 242) to a predetermined voltage (V L ) higher than the gate potential of the switching field effect transistor in next stage and lower than the first voltage (+ V).
Claim 2
Dependent Claim
359 words
A circuit for performing a predetermined logic function, having a plurality of logic elements (40, 42, 44, 46, 150, 152, 154, 156, 158, 240, 242) each of which includes at least one switching transistor (10, 12, 14, 72, 74, 160, 162, 176, 178, 180, 182, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) and which are connected in cascade with each other, characterized in that said switching transistors included in said logic elements (40, 42, 44, 46, 150, 152, 154, 156, 158, 240, 242) are depletion-mode field effect transistors (10, 12, 14, 72, 74, 160, 162, 176, 178, 180, 182, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) having source electrodes commonly connected to each other and drain electrodes connected to a first terminal (28, 221, 270, 324) which is connected to an external power source (220) and which is supplied with a first voltage (+ V) higher than a second voltage at a second terminal (19, 222, 277, 331) connected to the external power source (220), and that said circuit comprises voltage level-controlling means connected between the commonly connected source electrodes of said switching field effect transistors (10, 12, 14, 72, 74, 160, 162, 176, 178, 180, 182, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) and said second terminal for maintaining the source electrodes at a predetermined third voltage (Vss) lower than the first voltage (+ V) and higher than the second voltage, and level-shifting means (32, 34, 36, 60, 64, 68, 78, 102, 104, 106, 108, 114, 116, 118, 120, 132, 134, 136, 138, 168, 192, 194, 196, 198, 256, 266, 326, 348) for level-shifting the voltage at the drain electrode of one switching field effect transistor (10, 12, 14, 160, 162, 176, 178, 180, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) included in each of said logic elements (40, 42, 44, 46, 150, 152, 154, 156, 158, 240, 242) to a predetermined voltage (V L ) higher than the gate potential of the switching field effect transistor in next stage and lower than the first voltage (+ V).
Claim 3
Dependent Claim
94 words
A circuit according to claim 1, characterized in that said circuit further comprises load means (20, 22, 24, 50, 52, 54, 76, 164, 184, 186, 188, 190, 254, 264, 320, 346) connected between said first terminal (28, 221, 270, 324) and the drain electrode of each of said logic elements (40, 42, 44, 46, 150, 152, 154, 156, 158, 240, 242), for receiving an electric power from the external power source (220) and for supplying a substantially constant current to said logic elements (40, 42, 44, 46, 150, 152, 154, 156, 158, 240, 242).
Claim 4
Dependent Claim
43 words
A circuit according to claim 2, characterized in that said load means comprises a plurality of depletion-mode field effect transistors (50, 52, 54, 76, 164, 184, 186, 188, 190, 254, 264, 320, 346) having gate and source electrodes commonly connected to each other.
Claim 5
Dependent Claim
91 words
A circuit according to claim 1, characterized in that said voltage level-controlling means comprises at least one voltage level-controlling device (58, 100) which receives substantially constant current flowing from the source electrodes of said switching field effect transistors (10, 12, 14, 72, 74, 160, 162, 176, 178, 180, 182, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) to said second terminal (19, 222, 277, 331) and which generates a voltage drop therein in response to the current, thereby maintaining the source electrodes at the third voltage (Vss).
Claim 6
Dependent Claim
122 words
A circuit according to claim 1, characterized in that said voltage level-controlling means comprises a plurality of voltage level-controlling devices (110, 112, 210, 212, 214, 216, 218, 230, 232, 278, 280) which receive substantially constant current flowing from the source electrodes of said switching field effect transistors (10, 12, 14, 72, 74, 160, 162, 176, 178, 180, 182, 246, 248, 260, 262, 302, 304, 310, 312, 336, 338, 340, 342) to said second terminal (19, 222, 277, 331) and which generate a voltage drop therein in response to the current, thereby maintaining the source electrodes at the third voltage (Vss) said voltage level controllers being connected between said source electrode and second terminal (19, 222, 277, 331) in parallel with each other.
Claim 7
Dependent Claim
17 words
A circuit according to claim 4, characterized in that said voltage level-controlling device comprises a resistor (100).
Claim 8
Dependent Claim
48 words
A circuit according to claim 4, characterized in that said voltage level-controlling device comprises a semiconductor diode (58) having an anode electrode connected to the source electrodes of said switching field effect transistors (10, 12, 14, 72, 74) and a cathode electrode connected to said second terminal (19).
Claim 9
Dependent Claim
16 words
A circuit according to claim 7, characterized in that said semiconductor diode includes Schottky diode (58).
Claim 10
Dependent Claim
25 words
A circuit according to claim 4, characterized in that said voltage level-controlling device comprises a series circuit of a plurality of semiconductor diodes (110, 112).
Claim 11
Dependent Claim
84 words
A circuit according to claim 1, characterized in that said circuit further comprises means (62, 66, 70, 80, 170, 200, 202, 204, 206, 258, 268, 33, 352) connected between said level-shifting means (60, 64, 68, 78, 102, 104, 106, 108, 114, 116, 118, 120, 132, 134, 136, 138, 168, 192, 194, 196, 198, 256, 266, 326, 348) and said second terminal (19, 222, 277, 331), for suppressing the variation in the third voltage (Vss) and for preventing the variation in the level shift voltage.
Claim 12
Dependent Claim
81 words
a circuit according to claim 10, characterized by further comprising means (130, 234, 236, 238) for absorbing pulse noise generated at the commonly connected source electrodes of said switching field effect transistors (10, 12, 14, 72, 74, 160, 162, 176, 178, 180, 182), said pulse noise absorbing means including at least one reverse-biased semiconductor diode (130, 234, 236, 238) having an anode electrode connected to said second terminal (19, 222) and a cathode electrode connected to said commonly connected source electrodes.
Claim 13
Dependent Claim
82 words
A circuit according to claim 10, characterized in that said third voltage variation-suppressing means comprises a depletion-mode field effect transistor (62, 66, 70, 80, 170, 200, 202, 204, 206, 258, 268, 332, 352) having a drain electrode connected to said level-shifting means (60, 64, 68, 78, 102, 104, 106, 108, 114, 116, 118, 120, 132, 134, 136, 138, 168, 192, 194, 196, 198, 256, 266, 326, 348) and gate and source electrodes commonly connected to said second terminal (19, 222, 277, 331).
Claim 14
Dependent Claim
42 words
A circuit according to claim 1, characterized in that said level-shifting means comprises a level-shifting device (60) connected between at least a pair of switching field effect transistors (10, 12) respectively included in said logic elements (40, 42) adjacent to each other.
Claim 15
Dependent Claim
53 words
A circuit according to claim 13, characterized in that said level-shifting device (60) is connected between the drain electrode of the switching field effect transistor (10) of the previous stage of said pair of switching field effect transistors and the gate electrode of the switching field effect transistor (12) of the following stage.
Claim 16
Dependent Claim
37 words
A circuit according to claim 14, characterized in that said level-shifting device includes at least one semiconductor diode (60) having a cathode electrode connected to the gate electrode of said following stage switching field effect transistor (12).
Claim 17
Dependent Claim
19 words
A circuit according to claim 14, characterized in that said level-shifting device includes a resistor (102, 104, 106, 108).
Claim 18
Dependent Claim
26 words
A circuit according to claim 14, characterized in that said level-shifting device includes a series circuit of a plurality of semiconductor diodes (114, 116, 118, 120).
Claim 19
Dependent Claim
25 words
A circuit according to any one of claims 15 or 17, characterized in that said semiconductor diode includes a Schottky diode (114, 116, 118, 120).
Claim 20
Dependent Claim
69 words
A circuit according to claim 14, characterized in that said level-shifting device includes a depletion-mode field effect transistor (132, 134, 136) having a drain electrode connected to said first terminal (28), gate electrode connected to the drain electrode of said previous stage swithing field effect transistor (10, 12, 14) and a source electrode connected to the gate electrode of said following stage switching field effect transistor (12, 14, 72).
Claim 21
Dependent Claim
39 words
A circuit according to claim 1, characterized in that at least one of said logic elements includes a plurality of switching transistors (246, 248) which are connected in parallel with each other and which are depletion-mode field effect transistors.
Claim 22
Dependent Claim
39 words
A circuit according to claim 1, characterized in that at least one of said logic elements includes a plurality of switching transistors (302, 304) which are depletion-mode field effect transistors and which are connected in series with each other.
References Cited (Backward Citations)
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