MULTIPLYING CIRCUIT, DIVISION CIRCUIT AND FIXED VALUE CALCULATING CIRCUIT TO BE OPERATED IN CURRENT MODE

摘要

PURPOSE: To obtain the multiplying circuit enabling high-speed calculation by composing the circuit of a current mirror to impress a first input current to a first transistor and a differential circuit equipped with a second current source to drive 3rd and 4th transistors with a current. ;CONSTITUTION: The multiplying circuit outputs a current I_o in proportion to the product of input currents IIN and I_w and is equipped with the current mirror composed of npn transistors Q1 and Q2, differential circuit composed of npn transistors Q3 and Q4, and current mirror 3 for output. A power supply voltage Vcc is impressed to the collector of the transistor Q2, and the current IBIAS₁ flows from the emitter by a current source 1. Then, a current source 2 is connected to the emitter connected to the transistors Q3 and Q4 in common by the differential circuit, the base of one transistor Q3 is controlled by an emitter potential VB of the transistor Q2, a current I₃ flowing to the collector becomes an output current, and the I₃ becomes an output current I_o by inverting the direction at the current mirror 3.;COPYRIGHT: (C)1993,JPO&Japio