These circuits consist of four independent, high gain, internally frequency compensated operational amplifiers. They operate from a single power supply over a wide range of voltages. Operation from split power supplies is also possible and the low power supply current drain is independent of the magnitude of the power supply voltage. All the pins are protected against electrostatic discharges up to 2000V (as a consequence, the input voltages must not exceed the magnitude of VCC+ or VCC-.)