GENERAL DESCRIPTION

The ADT14 is a temperature sensor and controller that generates an output voltage proportional to temperature and provides four temperature trip points. The four trip points, or temperature setpoints, and their hysteresis are determined by voltage levels set by the user. An on-chip voltage reference provides an easy method for setting the temperature trip points.

The ADT14 consists of a bandgap voltage reference combined with four matched comparators. The reference provides both a temperature-stable 2.5 V output, and a voltage proportional to absolute temperature (VPTAT) which has a precise temperature coefficient of 5 mV/K = 5 mV/(°C +273.15). The VPTAT output is nominally 1.49 V at +25°C. The comparators determine whether the VPTAT output is above the voltages set up by external resistive dividers (temperature trip points) and generate an open-collector output signal when one of their respective thresholds has been exceeded.

FEATURES

Four Programmable Temperature Setpoints

Programmable Thermal Hysteresis

Accuracy 638C Typ from –408C to +1258C

Temperature Output Scale Factor = 5 mV/K

Resistor Programmable Temperature Setpoints

5 mA Open-Collector Setpoint Outputs

Internal 2.5 V Reference

600 mA Max Quiescent Current at +5 V

APPLICATIONS

Power Supply Monitor and Control System

Multiple Fan Controller System

Workstation Thermal Management System