# MAX6639FATE+

**Maxim Integrated** · Pre-ordered Chips · TQFN-16(5x5)

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](https://www.analog.com/media/en/technical-documentation/data-sheets/MAX6639-MAX6639F.pdf) (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](docs/max6639fate-datasheet.pdf)