Two-channel temp monitor with integrated fan drive
The MAX6639ATE+T is a 2-channel temperature monitor from Analog Devices that also handles closed-loop fan control. It combines an internal temperature sensor, a remote diode-sensing channel, an ADC, a PWM fan-speed generator, and a tachometer counter in a single 16-pin TQFN package. The part is designed for thermal management in systems that need to monitor one local and one remote hot spot — CPU die, GPU core, or ambient — and drive a cooling fan proportionally. The remote channel delivers ±1°C maximum accuracy, which is tight enough for processor-grade thermal throttling thresholds. The local channel is rated at ±2°C maximum. Communication runs over I²C/SMBus, so the part integrates directly into the management bus common on server motherboards, base station controllers, and industrial compute modules. Supply range is 3V to 3.6V, matching a regulated 3.3V rail. The operating temperature span of -40°C to +125°C covers industrial and telecom enclosure environments. The 5x5 mm 16-TQFN with exposed pad needs a thermal land pattern on the PCB for proper heat sinking — the package itself dissipates the local sensor's self-heating.
What the accuracy ratings mean for the BOM
The ±1°C remote accuracy is the spec that decides fit. If the design monitors a CPU or FPGA die via a diode-connected transistor, this part keeps the reported temperature within 1°C of the actual junction. The remote sensing range extends from 0°C to 150°C, which covers the full operating envelope of most silicon junctions. The local sensor is specified over the -40°C to +125°C ambient range. Both channels report through the same I²C/SMBus interface, so one read transaction fetches both temperatures.
Lifecycle and supply posture
The MAX6639ATE+T carries an Active lifecycle status with ROHS3 compliance. For a production BOM, this part presents no imminent obsolescence risk.