INA333/INA333-Q1 Instrumentation Amplifiers Texas Instruments INA333/INA333-Q1 Precision Instrumentation Amplifiers are low-power, precision instrumentation amplifier offering excellent accuracy. The versatile 3-operational amplifier design, small size, and low-power make them ideal for a wide range of portable applications. A single external resistor sets any gain from 1 to 1000. The Texas Instruments INA333/INA333-Q1 is designed to use an industry-standard gain equation: G = 1 + (100kΩ / RG).