The NCT7904D is an evolving member of the Nuvoton Hardware Monitoring IC family that provides accurate voltage and temperature monitoring via Nuvoton’s SMART FAN™ IV fan control algorithms and advanced system protection mechanisms

An internal 10-bit ADC converts the monitored temperature with ±1℃accuracy. The remote inputs can be connected to CPU/GPU thermal diode, standalone thermal diode or thermistor, or, the device it can retrieve CPU temperature information directly via the Intel^® PECI3.0 interface (Platform Environment Control Interface) or AMD SB-TSI interface.  The NCT7904D can monitor Up to 5 temperature channels and 20 analog voltage inputs simultaneously.

For Fan control, the NCT7904D can monitor up to 12 fan tachometer inputs and control 4 fan outputs (DC or PWM mode) via either SMART FAN™ IV or Manual modes. The NCT7904D SMART FAN™ IV implementation supports multi-zoned linear temperatures and fan speed mapping with hysteresis to provide an easy method to implement quiet cooling solutions with maximum safety and flexibility.

The NCT7904D implements an array of system alert features, including PROCESSOR HOT, Case-open detection, and Watch Dog Timer functions.  Alarm signals include SMI#, TEMP_ALM#, VOLT_ALM#, and FAN_ALM#; and all threshold values can be set for immediately activating system protection.

The NCT7904D supports an SMBus master function to read the EEPROM configuration data and other SMBus devices. An SMBus address selection pin allows two NCT7904D devices to be used in a single system.