Maxim Integrated Products introduces the MAX31782, a system management microcontroller that combines six temperature measurement channels with six channels of closed-loop fan control. By monitoring multiple temperature points throughout the system, the MAX31782 enables enterprise system designers to implement highly precise zoned-cooling schemes. This approach minimizes system power consumption and cooling costs by individually adjusting the speed of each fan to deliver the exact amount of cooling required by each zone. Added benefits of this technique include increased reliability through reduced fan wear, compensation for fan speed variances due to dust accumulation, and acoustic noise reduction.
A completely C-language programmable solution, the MAX31782 allows system designers to quickly and easily customize algorithms for precision zoned cooling in complex systems such as servers, network switches and routers, and base stations.
Features:
- MAXQ20, High-Performance, 16-Bit µC
- Efficient C-Language Programming
- 36KWords Total Program Memory
- 32KWords Flash Program Memory
- 4KWords ROM Program Memory
- 1KWords Data RAM
- 12-Bit ADC with 7-Input Mux for Temperature and Voltage Monitoring
- Temperature Measurement Analog Front-End
- 0.125NC Resolution
- Diode Series Resistance Cancellation
- Six Timer/Fan Tachometer Inputs
- Six 16-Bit PWM Outputs for Fan Speed or D/A Applications
- 5-Bit GPIO Ports
- SMBus/I2C-Compatible Slave Interface for Host Communication with Password-Protected Flash Programming
- I2C-Compatible Master Interface for Slave Expansion
- Power-On Reset and Brownout Monitors
- JTAG Port Supports In-System Debug and Flash Programming
- Internal Oscillator Requires No Crystal
- 2.7V to 5.5V Operating Voltage Range
MAX31782 provides the most sophisticated zoned-cooling solution
The conventional circuit for implementing zoned cooling requires a microcontroller and an external multichannel temperature sensor. Compared to this multichip approach, the MAX31782 consumes 55% less board space and reduces cost by at least 25%.
Moreover, Maxim's solution offers the added benefit of higher precision. It incorporates a 6-channel, 12-bit analog-to-digital converter (ADC) with a temperature-sensing analog front-end (AFE) that allows direct connection to thermal diodes. The AFE offers 0.125°C resolution, series resistance cancellation for the entire external diode circuit, and configurable ideality factor to deliver the highest temperature measurement accuracy.
The MAX31782 can be directly connected to up to six remote thermal diodes, which are typically integrated on CPU, FPGA, and ASIC ICs. Using the on-chip master I2C interface, additional temperature points can be monitored with external digital temperature ICs, such as Maxim's high-accuracy DS7505. Based on the temperature information, the MAX31782 can control up to six cooling fans, each with an independent 16-bit PWM output and timer/tachometer input. It thus provides a complete closed-loop system for multiple fans, allowing accurate zoned cooling with minimum energy expended for fan power.
Development tools accelerate system design
Based on a 16-bit MAXQ RISC microcontroller core, the MAX31782 provides ample space for programs and data with 32-KWord reprogrammable flash and 1-KWord RAM for data storage. C-language and assembly-based programming is supported with the IAR Embedded Workbench for MAXQ, available in time-limited or code-limited versions for free product evaluation. This tool also accommodates in-circuit flash programming and code debugging through the MAX31782's integrated JTAG-compatible debug port.
