Master slice semiconductor integrated circuit with output drive current control

• Main Authors: OGUCHI; YASUHIRO, SAKUDA; TAKASHI, HIRABAYASHI; YASUHISA, OOKAWA; KAZUHIKO
• Format: Patent
• Language: English
• Published: 04.10.1994
• Edition: 5
• Subjects: BASIC ELECTRIC ELEMENTS; BASIC ELECTRONIC CIRCUITRY; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; PULSE TECHNIQUE; SEMICONDUCTOR DEVICES

PCT No. PCT/JP91/00975 Sec. 371 Date May 7, 1992 Sec. 102(e) Date May 7, 1992 PCT Filed Jul. 18, 1991 PCT Pub. No. WO92/02052 PCT Pub. Date Feb. 6, 1992.An output current varying circuit 10 includes a control signal generating circuit 12, an output current supplying circuit 14 and an output terminal 16. Circuit 12 receives an output signal Sout of a dedicated logic circuit 11, and an output signal S1 from a predetermined circuit or an external signal S2 from an input terminal 13, and generates first and second control signals C1 and C2. Circuit 14 is constituted by two P-channel MIS transistors Tr1 and Tr2 connected in parallel between high potential Vdd and output terminal 16. When output signal Sout from logic circuit 11 is at H level, transistor Tr2 is in an on state and an output current i at H level appears on output terminal 16. When output signal Sout is a L level and a current value changing signal S is at L level, transistors Tr1 and Tr2 are both in an off state and the output current is zero. When output signal Sout is at L level and signal S is at H level, transistors Tr1 and Tr2 are both in the off state and an output current 2i at H level appears. Thus, the current value of an external Xout supplied to output terminal 16 can be selectively set at i or 2i, so that power consumption can be reduced and flexibility in high power driving can be obtained depending on the environment where the chip is used.