The LM331N/NOPB Voltage to Frequency & Frequency to Voltage PREC VLTG-TO-FREQ Converter is an integrated circuit (IC) designed and manufactured by Texas Instruments. It is designed for precision voltage-to-frequency and frequency-to-voltage conversion for transducer signal conditioning and control loops. The part uses internal current sources and charge/discharge-controlled capacitors to provide cycle-by-cycle adjustment. It has a maximum operating frequency of 100kHz, an input voltage range of ±4.5V, and an input impedance of 500µA. It offers improved accuracy with a non-volatile conversion gain which is set at the factory. In addition, it has low power consumption (20mA max), output current drive up to 10mA, and is designed to operate over a temperature range of -40°C to +125°C. It also has a floating output for both voltage-to-frequency and frequency-to-voltage operation and a logic output which can be used to indicate the end of a conversion or an error condition.