ADM1031ARQZ

Product Summary

The ADM1031ARQZ is an ACPI-compliant, three-channel digital thermometer and under/overtemperature alarm for use in personal computers and thermal management systems. Optimized for the Pentium III, the part offers a 1℃ higher accuracy, which allows system designers to safely reduce temperature guard-banding and increase system performance. Two PWM fan control outputs control the speed of two cooling fans by varying output duty cycle. Duty cycle values between 33% and 100% allow smooth control of the fans. The speed of each fan can be monitored via TACH inputs, which can be reprogrammed as analog inputs to allow speeds for 2-wire fans to be measured via sense resistors. The ADM1031ARQZ also detects a stalled fan. A dedicated fan speed control loop provides control without the intervention of CPU software. The ADM1031ARQZ also ensures that if the CPU or system locks up, each fan can still be controlled based on temperature measurements, and the fan speed is adjusted to correct any changes in system temperature. Fan speed can also be controlled using existing ACPI software.

Parametrics

ADM1031ARQZ absolute maximum ratings: (1)Positive Supply Voltage (VCC): 6.5 V; (2)Voltage on Any Input or Output Pin: －0.3 to +6.5 V; (3)Input Current at Any Pin: ±5 mA; (4)Package Input Current: ±20 mA; (5)Maximum Junction Temperature (TJ max): 150 ℃; (6)Storage Temperature Range: －65 to +150 ℃.

Features

ADM1031ARQZ features: (1)0.125℃Resolution on External Temperature Channels; (2)Control Loop to Minimal Acoustic Noise and Battery Consumption; (3)Remote Temperature Measurement Accurate to 1℃Using Remote Diode (Two Channels); (4)Local Sensor with 0.25℃Resolution; (5)Pulse Width Modulation (PWM)Fan Control for 2 Fans; (6)Programmable PWM Frequency and PWM Duty Cycle; (7)Tach Fan Speed Measurement (Two Channels); (8)Analog Input to Measure Fan Speed of 2-Wire Fans (Using Sense Resistor); (9)2-Wire System Management Bus (SMBus)with ARA Support.

Diagrams