Voltage gain amplifier architecture for automotive radar

A circuit, comprising:

• a differential amplifier comprising first and second input transistors receiving first and second regulated input differential voltages, the first and second input transistors being coupled in a differential arrangement between first and second current sourcing circuits and first and second current sinking circuits, wherein the first and second current souring circuits are configured to source more current than is sunk by the first and second current sinking circuits;
• wherein the differential amplifier includes first and second resistances coupled in series between a first node at which the first input transistor and the first current sinking circuit are coupled and a second node at which the second input transistor and the second current sinking circuit are coupled;
• a first amplifier configured to generate an adjustment signal for the first and second current sourcing circuits based upon a difference between an input common mode reference voltage and a voltage at a tap between the first and second resistances;
• and
• an output amplification circuit configured to amplify differential output voltages from the differential amplifier to thereby produce final differential output voltages.

A circuit, comprising:

• a differential amplifier comprising first and second input transistors receiving first and second regulated input differential voltages, the first and second input transistors being coupled in a differential arrangement between first and second current sourcing circuits and first and second current sinking circuits, wherein the first and second current souring circuits are configured to source more current than is sunk by the first and second current sinking circuits;
• an output amplification circuit coupled to amplify different output voltages from the differential amplifier to thereby produce final differential output voltages;
• and
• adjustment circuitry configured to adjust the currents sourced by the first and second current sourcing circuits such that voltage across the first and second input transistors remains constant, and such that the currents sourced by the first and second current sourcing circuits are adjusted in magnitude with adjustment to magnitude of the currents sunk by the first and second current sinking circuits.

A circuit, comprising:

• a voltage gain amplifier comprising:
• a first fixed current source configured to source a first current;
• a second fixed current source configured to source a second current;
• a third fixed current source configured to sink a third current;
• a fourth fixed current source configured to sink a fourth current;
• a first transistor having a first conduction terminal coupled to the first fixed current source, a second conduction terminal coupled to the third fixed current source, and a control terminal coupled to receive a first regulated differential input voltage;
• a first input amplifier having a first input receiving a first differential input signal, a second input coupled to the second conduction terminal of the first transistor, and an output generating the first regulated differential input voltage;
• a second transistor having a first conduction terminal coupled to the second fixed current source, a second conduction terminal coupled to the fourth fixed current source, and a control terminal coupled to receive a second regulated differential input voltage;
• a second input amplifier having a first input receiving a second differential input signal, a second input coupled to the second conduction terminal of the second transistor, and an output generating the second regulated differential input voltage;
• an output amplifier having inputs coupled to the first conduction terminals of the first and second transistors to receive differential output voltages therefrom, and outputs generating amplified differential output voltages therefrom;
• a resistance coupled between the second conduction terminals of the first and second transistors;
• a first adjustable current source coupled in parallel with the first fixed current source;
• a second adjustable current source coupled in parallel with the second fixed current;
• and
• an amplifier having a first input coupled to a center tap of the resistance and a second input coupled to a reference voltage, wherein the amplifier has an output at which a control signal of the first and second adjustable current sources is generated.