Overview
The NCT7491MNTXG, produced by onsemi, is a two-wire serially programmable hardware monitor designed for comprehensive thermal management and fan control. This device can monitor two remote temperature zones, its own ambient temperature, and CPU temperatures via a PECI 3.0 single wire interface. It also functions as an SMBus compatible master, enabling automatic readings from thermal sensors on the SMBus. The NCT7491MNTXG is capable of controlling the speed of three fans using PWM control and monitoring the speed of four fans. Additionally, it includes four analog inputs for voltage monitoring of 12 V, 5 V, 2.5 V, and Vccp channels, along with supply voltage and PECI VTT voltage monitoring.
Key Specifications
| Parameter | Min | Typ | Max | Unit | Test Conditions/Comments |
|---|---|---|---|---|---|
| Supply Voltage (VCC) | 3.0 | 3.3 | 3.6 | V | |
| Supply Current (ICC) | 1.5 | 5 | mA | Interface inactive, ADC active | |
| Local Sensor Accuracy | ±0.5 | ±3.5 | °C | 0°C ≤ TA ≤ 85°C | |
| Remote Diode Sensor Accuracy | ±0.5 | ±3.5 | °C | 0°C ≤ TA ≤ 85°C, −40°C ≤ TD ≤ 125°C | |
| Maximum Junction Temperature (TJ max) | 150 | °C | |||
| Storage Temperature Range | −65 | 150 | °C | ||
| Lead Temperature, Soldering IR Reflow Peak Temperature | 220 | °C |
Key Features
- PECI 3.0 Master for CPU Monitoring
- SMBus Compatible Master
- On-chip Temperature Sensor
- 2 Remote Sensor Channels with Series Resistance Cancellation
- 3 PWM Fan Control Outputs
- 4 Tach Monitoring Inputs
- PWM Automatic Fan Speed Control
- 4 Analog Inputs for Voltage Monitoring (12 V, 5 V, 2.5 V, Vccp)
- Vdd Supply Voltage Monitoring and PECI VTT Voltage Monitoring
- Overtemperature Outputs and Limit Comparison of Monitored Channels
- SMBus Address Selection Allows up to 3 Devices
- Meets SMBus 2.0 Electrical Specifications (fully SMBus 1.1 compliant)
- Pb-Free, Halogen Free/BFR Free, and RoHS Compliant
- Up to 3 GPIO pins for digital control or signalling
Applications
- System Thermal Management
- Desktop Computers
- Servers
- Mobile Platforms
Q & A
- What is the primary function of the NCT7491MNTXG?
The NCT7491MNTXG is a two-wire serially programmable hardware monitor designed for thermal management and fan control.
- How many remote temperature zones can the NCT7491MNTXG monitor?
The NCT7491MNTXG can monitor two remote temperature zones and its own ambient temperature.
- What interface does the NCT7491MNTXG use for CPU temperature monitoring?
The NCT7491MNTXG uses a PECI 3.0 single wire interface for CPU temperature monitoring.
- How many fans can the NCT7491MNTXG control and monitor?
The NCT7491MNTXG can automatically control the speed of three fans using PWM control and monitor the speed of four fans.
- What types of voltage monitoring does the NCT7491MNTXG support?
The NCT7491MNTXG supports voltage monitoring of 12 V, 5 V, 2.5 V, and Vccp channels, as well as supply voltage and PECI VTT voltage monitoring.
- What communication interface does the NCT7491MNTXG use?
The NCT7491MNTXG uses an SMBus/I2C interface compatible with industry standard protocols.
- What is the supply voltage range for the NCT7491MNTXG?
The NCT7491MNTXG operates over a supply range of 3.0 V to 3.6 V.
- What are the packaging options for the NCT7491MNTXG?
The NCT7491MNTXG is available in a 24-lead QFN or QSOP package.
- Is the NCT7491MNTXG compliant with environmental regulations?
Yes, the NCT7491MNTXG is Pb-Free, Halogen Free/BFR Free, and RoHS Compliant.
- How many GPIO pins are available on the NCT7491MNTXG?
Up to 3 GPIO pins are available for digital control or signalling.
