LEVEL SHIFTING CIRCUIT

• Main Authors: HONGU M,JA, HISHIKI Y,JA
• Format: Patent
• Language: English
• Published: 26.11.1974
• Subjects: AMPLIFIERS; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; PULSE TECHNIQUE

A level shifting circuit includes first, second and third transistors of one conductivity type each having base, emitter and collector electrodes. The collector and emitter electrodes of the first and second transistors are connected in series between a pair of voltage terminals and the collector electrode of the second transistor is further connected to the base electrode of the third transistor. A first resistor is included in the series circuit between the emitter electrode of the first transistor and the collector electrode of the second transistor, and a second resistor is included in the emitter circuit of the second transistor. A biasing circuit is provided to bias the base electrode of the second transistor. If an input signal reference to a first DC voltage level is applied to the base electrode of the first transistor, an output signal referenced to a second DC voltage level is derived from one of the emitter and collector electrodes of the third transistor. The ratio between the resistance values of the first and second resistors is selected so that the difference between the first and second DC voltage levels to which the input and output signals are referenced is maintained constant regardless of the temperature. The magnitude of the difference between the first and second DC voltage levels is adjusted by the biasing voltage applied to the base electrode of the second transistor.