×

Transit mixer with current mode input

  • US 5,642,071 A
  • Filed: 11/07/1995
  • Issued: 06/24/1997
  • Est. Priority Date: 11/07/1994
  • Status: Expired due to Term
First Claim
Patent Images

1. Differential mixer (DM) coupled between a first (VCC) and a second (GND) voltage supply terminal for multiplying a first differential input voltage supplied at a first differential voltage input (LO) with a second differential input voltage supplied at a second differential voltage input (VIN), said differential mixer (DM) including a cross-connected pair of differential amplifiers (A;

  • B) responsive to said first differential voltage input and coupled between said first (VCC) voltage supply terminal and a differential pair of mixing input terminals (J1;

    J2) to which are also coupled a voltage-to-current converter means (VIC) and a current source (I1;

    I2), said current source including two identical parallel current branches, each connected between distinct differential amplifiers (A;

    B) via a distinct mixing input terminal (J1;

    J2) and said second (GND) voltage supply terminal, said parallel current branches each comprising a series connection of a transistor (T1;

    T2) and a resistor (R5;

    R7) and said voltage-to-current converter means responsive to said second differential voltage input for converting said second differential input voltage to a differential current (INN) supplied to said differential mixing input terminals, said voltage-to-current converter means including a differential cascode circuit of transistors (P1;

    P2) having input terminals (J3;

    J4) to which said second differential voltage input are connected via resistors (RI1;

    RI2), output terminals connected to said mixing input terminals which are current output terminals (TI1;

    TI2), and control terminals to which a constant reference voltage terminal (VCC/2) is coupled, said voltage-to-current converter means further including a first pair of constant current sources (PB1, PB2) coupling said first (VCC) voltage supply terminal to the input terminals of said transistors, and a second pair of constant current sources (NB1, NB2) coupling the output terminals of said transistors to said second (GND) voltage supply terminal.

View all claims
  • 11 Assignments
Timeline View
Assignment View
    ×
    ×