Patent ID: 9590576
Date: 2017-03-07
CPC Classifications: H03F

Claim:
1. A differential amplifier for generating a differential output current from a differential input voltage, comprising: a pair of input terminals configured to externally receive the differential input voltage; a first differential pair including a first transistor, a second transistor, a first resistor, and a second resistor, the first transistor and the second transistor each having a first current terminal connected to each other through the first resistor and the second resistor connected in series to the first resistor, the first differential pair being configured to generate a first differential signal in response to the differential input voltage; a pair of level shifters configured to generate a shifted differential voltage shifted from the differential input voltage; a second differential pair including a third transistor, a fourth transistor, a third resistor, and a fourth resistor, the third transistor and the fourth transistor each having a first current terminal thereof connected to each other through the third resistor and the fourth resistor connected in series to the third resistor, the second differential pair being configured to generate a second differential signal in response to the shifted differential voltage; a current source configured to provide a constant current to the first and second differential pairs; and a pair of output terminals configured to externally output the differential output current containing the first differential signal and the second differential signal.