OP221 is a low power dual operational amplifier that can be used with a single or dual power supply. The OP221 has a wide supply voltage range, wide input voltage range and low supply current drain, making it well-suited for operation from batteries or unregulated power supplies. The excellent specifications of the individual amplifiers combined with the tight matching and temperature tracking between channels make the OP221 a very suitable amplifier for battery or unregulated power supply operation.