Abstract: We can apply a BiCMOS integrated circuit with only resistors and no transistors to solve adifficult design problem. The mythically perfect operational amplifier\'s gain and temperature coefficient aredependent on external resistor values. Maxim precision resistor arrays are manufactured together on asingle die and then automatically trimmed, to ensure close ratio matching. This guarantees that theoperational amplifier (op amp) gain and temperature coefficient are predictable and reliable, even withlarge production volumes.