The LM9040 is a dual sensor interface circuit consisting of two independent sampled input differential amplifiers designed for use with conventional Lambda Oxygen Sensors The Lambda Sensor is used for monitoring the oxygen concentration in the exhaust of gasoline engines using catalytic after treatment and will deliver a voltage signal which is dependent on the air-fuel mixture The gain of the amplifiers are internally set and can directly convert the Lambda sensor output voltage to a level suitable for A D conversion in a system using a 5V reference