MAX6639FATE+ from Maxim Integrated, in a TQFN-16(5x5). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin	Name	Type	Function
1	PWM2	output	Open-drain output to the gate or base of the power transistor driving fan 2, which requires a pullup resistor that may go to up to 13.5V regardless of VCC.
2	TACH2	input	Tachometer input from fan 2, which requires a pullup resistor that may go to up to 13.5V regardless of VCC.
3	FANFAIL	output	Active-low, open-drain fan-failure output that is open circuit when VCC = 0.
4	THERM	output	Active-low, open-drain thermal alarm output, typically used for clock throttling, that is open circuit when VCC = 0.
5	OT	output	Active-low, open-drain overtemperature output, typically used for system shutdown or clock throttling, that can be pulled up to 5.5V regardless of VCC and is open circuit when VCC = 0.
6	VCC	power_in	Power-supply input, 3.3V nominal within a 3.0V to 3.6V operating range, to be bypassed to GND with a 0.1µF capacitor.
7	GND	power_in	Ground; connect to a clean ground reference.
8	DXP1	passive	Combined current source and A/D positive input for a remote diode, which must not be left unconnected (connect to DXN if no remote diode is used) and needs a 2200pF capacitor between DXP and DXN for noise filtering.
9	DXN	passive	Remote-diode current sink input, to which the cathode of the remote-diode-connected transistor connects.
10	DXP2	passive	Combined current source and A/D positive input for a remote diode, which must not be left unconnected (connect to DXN if no remote diode is used) and needs a 2200pF capacitor between DXP and DXN for noise filtering.
11	ADD	input	Address input that sets the device slave address; connect to GND, to VCC, or leave unconnected to select one of three unique addresses (see Table 1).
12	ALERT	output	Active-low, open-drain SMBus alert output.
13	SCL	input	SMBus serial-clock input that can be pulled up to 5.5V regardless of VCC.
14	SDA	bidirectional	SMBus serial-data input/output, open drain, that can be pulled up to 5.5V regardless of VCC and is open circuit when VCC = 0.
15	PWM1	output	Open-drain output to the gate or base of the power transistor driving fan 1, which requires a pullup resistor that may go to up to 13.5V regardless of VCC.
16	TACH1	input	Tachometer input from fan 1, which requires a pullup resistor that may go to up to 13.5V regardless of VCC.
17	EP	passive	Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter	Value
Manufacturer	Maxim Integrated
Package	TQFN-16(5x5)
Category	Interface ICs
Pins	17

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter	Symbol	Min	Typ	Max	Unit	Conditions	Page
Operating Supply Voltage Range	VCC	3		3.6	V		2
Operating Temperature Range		-40		125	°C		2
Standby Current			3	10	µA	SMB static, sleep mode	2
Operating Current			0.5	1	mA	Interface inactive, ADC active	2
External Temperature Error		-1		1	°C	VCC = +3.3V, +60°C ≤ TA ≤ +100°C and +60°C ≤ TR ≤ +100°C	2
External Temperature Error		-2.5		2.5	°C	VCC = +3.3V, +40°C ≤ TA ≤ +100°C and 0°C ≤ TR ≤ +145°C	2
External Temperature Error		-3.8		3.8	°C	VCC = +3.3V, 0°C ≤ TR ≤ +145°C	2
Internal Temperature Error (MAX6639FAEE option, n = 1.021)		-7.7		-2.5	°C	VCC = +3.3V, +25°C ≤ TA ≤ +100°C	2
Internal Temperature Error (MAX6639FAEE option, n = 1.021)		-10.4		-0.1	°C	VCC = +3.3V, 0°C ≤ TA ≤ +125°C	2
Supply Sensitivity of Temperature Measurement		-0.2		0.2	°C/V		2
Conversion-Rate Timing Error		-10		10	%		2
PWM Frequency Error		-10		10	%		2
Tachometer Accuracy		-3		3	%	TA = +60°C to +100°C	2
Remote-Diode Sourcing Current (High level)		70	100	130	µA	High level	2
Remote-Diode Sourcing Current (Low level)		7	10	13	µA	Low level	2
Output Low Voltage (ALERT, FANFAIL, THERM, OT, SDA)	VOL			0.4	V	ISINK = 6mA	3
Output Low Voltage (PWM1, PWM2)	VOL			0.4	V	PWM1, PWM2, ISINK = 4mA	3
Output High Leakage Current (OT, ALERT, FANFAIL, THERM, SDA, PWM1, PWM2)	IOH			1	µA		3
Logic-Low Input Voltage (SDA, SCL, THERM, TACH1, TACH2)	VIL			0.8	V		3
Logic-High Input Voltage (SDA, SCL, THERM, TACH1, TACH2)	VIH	2.1			V	VCC = 3.3V	3
Input Leakage Current (SDA, SCL, THERM, TACH1, TACH2)				1	µA	VIN = VCC or GND	3
Serial Clock Frequency	fSCL	10		100	kHz		3
Clock Low Period	tLOW	4			µs	10% to 10%	3
Clock High Period	tHIGH	4.7			µs	90% to 90%	3
Bus Free Time Between STOP and START Conditions	tBUF	4.7			µs		3
SMBus START Condition Setup Time	tSU:STA	4.7			µs	90% of SMBCLK to 90% of SMBDATA	3
START Condition Hold Time	tHD:STO	4			µs	10% of SDA to 10% of SCL	3
STOP Condition Setup Time	tSU:STO	4			µs	90% of SCL to 10% of SDA	3
Data Setup Time	tSU:DAT	250			ns	10% of SDA to 10% of SCL	3
Data Hold Time	tHD:DAT			300	ns	10% of SCL to 10% of SDA (Note 4)	3
SMBus Fall Time	tF			300	ns		3
SMBus Rise Time	tR			1000	ns		3
SMBus Timeout	tTIMEOUT	58	74	90	ms		3
VCC to GND	VCC	-0.3		4	V		2
PWM1, PWM2, TACH1, and TACH2 to GND		-0.3		13.5	V		2
DXN to GND		-0.3		0.8	V		2
SCL, SDA, THERM, OT, FANFAIL, ADD, and ALERT to GND		-0.3		6	V		2
SDA, OT, THERM, ALERT, FANFAIL, PWM1, and PWM2 Current		-1		50	mA		2
DXN Current		-1		1	mA	±1mA	2
Junction Temperature				150	°C		2
Storage Temperature Range		-65		150	°C		2
Lead Temperature (soldering)				300	°C	soldering, 10s	2
Soldering Temperature (reflow)				260	°C		2

CAD (KiCad official)

Symbol: MAX6639FATE+
Footprint: Package_DFN_QFN:QFN-16-1EP_5x5mm_P0.8mm_EP2.7x2.7mm
3D model: TQFN-16(5x5) (KiCad packages3D, STEP)
3D model files: max6639fate-etched.step / max6639fate-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); max6639fate.step / max6639fate.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Maxim Integrated datasheet (22 pp, sha256 bf52604981deae9c, retrieved 2026-10-30, tier: manufacturer)
Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF

MAX6639FATE+

Verified MAX6639FATE+

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

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