LM324 Quad Op Amp IC

From Micro Ohm's description

These devices consist of four independent high-gain frequency-compensated operational amplifiers that are designed specifically to operate from a single supply over a wide range of voltages. Applications include transducer amplifiers, dc amplification blocks, and all the conventional operational-amplifier circuits that now can be more easily implemented in single-supply-voltage systems. For example, the LM324 can be operated directly from the standard 5-V supply that is used in digital systems and provides the required interface electronics, without requiring additional ?15-V supplies. Datasheet: LM324.pdf