Two-channel temperature monitor with ±1°C remote accuracy
The Maxim Integrated MAX6639AEE+ is a 2-channel temperature monitor and fan controller in a 16-QSOP package. It combines an internal local temperature sensor with support for one external diode-connected transistor (typically a 2N3904 or CPU/GPU embedded diode), achieving ±2°C local accuracy and ±1°C remote accuracy. The part integrates an ADC, a PWM fan-speed generator, and a tachometer counter, all accessible over the I²C/SMBus interface.
The external sensor path reads temperatures from 0°C to 150°C, which covers CPU hotspots and power-stage thermals. Supply voltage is 3V to 3.6V, matching standard 3.3V system-management rails.
For BOM planning, there is no forced migration risk in the near term.
16-pin SSOP/QSOP — field-swappable footprint
The 1.27mm pitch is fine enough for compact layouts but still hand-solderable with a decent iron and magnification. No exposed pad means no thermal-via stencil — just standard decoupling on the supply pin.
The ±1°C remote accuracy is the headline number — it determines whether this part can replace a discrete thermistor + ADC chain in precision thermal management. The integrated PWM generator and tach counter eliminate a separate fan controller IC, saving board area and BOM count. The I²C/SMBus interface is standard on most BMCs and system-management controllers, so software integration is straightforward.