ISO165 and ISO175 are precision isolated instrumentation amplifiers incorporating a novel duty cycle modulation-demodulation technique and excellent accuracy. A single external resistor sets the gain. Internal input protection can withstand up to ±40V without damage. The signal is transmitted digitally across a differential capacitive barrier. With digital modulation the barrier characteristics do not affect signal integrity. This results in excellent reliability and good high frequency transient immunity across the barrier. Both the amplifier and barrier capacitors are housed in a plastic DIP. ISO165 and ISO175 differ in frequency response and linearity. These amplifiers are easy to use. A power supply range of ±4.5V to ±18V makes these amplifiers ideal for a wide range of applications.