| 摘要 |
PURPOSE:To speed up the operation of a comparator circuit by fixing the collector voltage of transistors (TR) which constitute an input differential couple, making emitter currents of TRs whose bases are connected to the collectors of said TRs constant, and fixing the base collector voltage of each TR at a constant voltage. CONSTITUTION:The collector voltage of either of TRs in the input differential couple, i.e. Q1 is fixed at a constant voltage 3VBE which is the sum of base- emitter voltages of TRs Q3 and Q10, and Q5, and the collector voltage of the other TR Q2 is fixed at a constant voltage 3VBE which is the sum of base- emitter voltages of TRs Q4 and Q11, and Q9. Consequently, the emitter currents of output TRs Q3 and Q4 become constant. The base-collector voltages of the TRs Q10 and Q11, on the other hand, are fixed at the constant base-emitter voltage VBE of the TRs Q3 and Q4. Therefore, the TRs Q1-Q4 and Q10 and Q11 are prevented from being saturated, so the comparator circuit which operates at a high speed is formed. |
