The NE5230 is a very low voltage operational amplifier that can perform with a voltage supply as low as 1.8 V or as high as 15 V. In addition， split or single supplies can be used， and the output will swing to ground when applying the latter. There is a bias adjusting pin which controls the supply current required by the device and thereby controls its power consumption. If the part is operated at ±0.9 V supply voltages， the current required is only 110 A when the current control pin is left open. Even with this low power consumption， the device obtains a typical unity gain bandwidth of 250 kHz. When the bias adjusting pin is connected to the negative supply， the unity gain bandwidth is typically 600 kHz while the supply current is increased to 600 A. In this mode， the part will supply full power output beyond the audio range. The NE5230 also has a unique input stage that allows the common?mode input range to go above the positive and below the negative supply voltages by 250 mV. This provides for the largest possible input voltages for low voltage applications. The part is also internally?compensated to reduce external component count. The NE5230 has a low input bias current of typically ±40 nA， and a large open?loop gain of 125 dB. These two specifications are beneficial when using the device in transducer applications. The large open?loop gain gives very accurate signal processing because of the large “excess” loop gain in a closed?loop system. The output stage is a class AB type that can swing to within 100 mV of the supply voltages for the largest dynamic range that is needed in many applications. The NE5230 is ideal for portable audio equipment and remote transducers because of its low power consumption， unity gain bandwidth， and 30 nV/√Hz noise specification.