| 摘要 |
An operational amplifier having a high voltage power supply (Vcc) and a low voltage power supply (Vss) is disclosed. The operational amplifier receives first and second input signals (IN1, IN2) and amplifies a voltage difference between the first and second input signals to generate an amplified signal (OUT). The operational amplifier has a first differential amplifier (1) having a pair of first type transistors (Tr1, Tr2) that are activated by the first and second input signals having a voltage greater than the voltage of the low voltage power supply (Vss). The first differential amplifier (1) transmits a first output signal (S1) in response to the voltage difference between the first and second input signals (IN1, IN2). A second differential amplifier (2) has a pair of second type transistors (Tr3, Tr4) that are activated by the first and second input signals (IN1, IN2) having a voltage smaller than the voltage of the high voltage power supply (Vcc). The second differential amplifier (2) transmits a second output signal (S2) in response to the voltage difference between the first and the second input signals (IN1, IN2). An output circuit (3) synthesizes the first and second output signals (S1, S2). The output circuit (3) is activated by a synthesized signal to transmit the amplified signal (OUT). <IMAGE> |
