# MAX31855TASA+T

**Analog Devices Inc Maxim Integrated** · ADCs/DACs - Special Purpose · SO-8

MAX31855TASA+T from Analog Devices Inc Maxim Integrated, in a SO-8. 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 | GND | power_in | Ground reference for the device; the datasheet states all voltages are referenced to GND. |
| 2 | T- | input | Thermocouple negative input (wire connections per Table 1); the datasheet says do not connect this pin to GND. |
| 3 | T+ | input | Thermocouple positive input (wire connections per Table 1), with internal circuitry that reduces noise errors from the thermocouple wires. |
| 4 | VCC | power_in | Power-supply voltage, 3.0V to 3.6V (3.3V typical), with absolute maximum range of -0.3V to +4.0V. |
| 5 | SCK | input | Serial-clock input for the SPI-compatible read-only interface, with a maximum serial-clock frequency of 5 MHz. |
| 6 | CS | input | Active-low chip select; drive CS low to enable the serial interface and output data on SO. |
| 7 | SO | output | Serial-data output that delivers the conversion data bits, starting with D31 once CS is driven low and clocked by SCK. |
| 8 | DNC | unconnected | Do Not Connect; leave this pin unconnected. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Analog Devices Inc Maxim Integrated |
| Package | SO-8 |
| Category | Data Acquisition |
| Pins | 8 |

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Power-Supply Voltage | VCC | 3 | 3.3 | 3.6 | V | (Note 2) | 2 |
| Input Logic 0 | VIL | -0.3 |  | 0.8 | V |  | 2 |
| Input Logic 1 | VIH | 2.1 |  |  | V |  | 2 |
| Power-Supply Current | ICC |  | 900 | 1500 | µA |  | 2 |
| Thermocouple Input Bias Current |  | -100 |  | 100 | nA | TA = -40°C to +125°C, 100mV across the thermocouple inputs | 2 |
| Power-On Reset Voltage Threshold | VPOR | 2 |  | 2.5 | V | (Note 3) | 2 |
| Output Low Voltage | VOL |  |  | 0.4 | V | IOUT = 1.6mA | 2 |
| Input Leakage Current | ILEAK | -1 |  | 1 | µA | (Note 7) | 4 |
| Thermocouple Gain and Offset Error, MAX31855T (T-type) |  | -2 |  | 2 | °C | TTHERMOCOUPLE = -270°C to +400°C, TA = -20°C to +85°C (Note 3) | 3 |
| Thermocouple Gain and Offset Error, MAX31855T (T-type) |  | -4 |  | 4 | °C | TTHERMOCOUPLE = -270°C to +400°C, TA = -40°C to +125°C (Note 3) | 3 |
| Internal Cold-Junction Temperature Error |  | -2 |  | 2 | °C | TA = -20°C to +85°C (Note 3) | 4 |
| Internal Cold-Junction Temperature Error |  | -3 |  | 3 | °C | TA = -40°C to +125°C (Note 3) | 4 |
| Serial-Clock Frequency | fSCL |  |  | 5 | MHz |  | 4 |
| SCK Pulse-High Width | tCH | 100 |  |  | ns |  | 4 |
| SCK Pulse-Low Width | tCL | 100 |  |  | ns |  | 4 |
| SCK Rise and Fall Time |  |  |  | 200 | ns |  | 4 |
| CS Fall to SCK Rise | tCSS | 100 |  |  | ns |  | 4 |
| SCK to CS Hold |  | 100 |  |  | ns |  | 4 |
| CS Fall to Output Enable | tDV |  |  | 100 | ns |  | 4 |
| CS Rise to Output Disable | tTR |  |  | 40 | ns |  | 4 |
| SCK Fall to Output Data Valid | tDO |  |  | 40 | ns |  | 4 |
| CS Inactive Time |  | 200 |  |  | ns | (Note 3) | 4 |
| Temperature Conversion Time (Thermocouple, Cold Junction, Fault Detection) | tCONV | 70 |  | 100 | ms | (Note 5) | 4 |
| Thermocouple Conversion Power-Up Time | tCONV_PU |  |  | 200 | ms | (Note 6) | 4 |
| Supply Voltage Range (VCC to GND) | VCC | -0.3 |  | 4 | V |  | 2 |
| All Other Pins |  | -0.3 |  |  | V | max = VCC + 0.3V | 2 |
| ESD Protection (All Pins, Human Body Model) |  | -2 |  | 2 | kV | Human Body Model | 2 |
| Operating Temperature Range |  | -40 |  | 125 | °C |  | 2 |
| Junction Temperature |  |  |  | 150 | °C |  | 2 |
| Storage Temperature Range |  | -65 |  | 150 | °C |  | 2 |
| Lead Temperature (soldering) |  |  |  | 300 | °C | 10s | 2 |
| Soldering Temperature (reflow) |  |  |  | 260 | °C |  | 2 |
| Power-On Reset Voltage Hysteresis |  |  | 0.2 |  | V |  | 2 |
| Power-Supply Rejection |  |  | -0.3 |  | °C/V |  | 2 |
| Input Capacitance | CIN |  | 8 |  | pF |  | 4 |
| Junction-to-Case Thermal Resistance (θJC) | θJC |  | 40 |  | °C/W | SO package (Note 1) | 2 |

## CAD (KiCad official)

- Symbol: `MAX31855TASA+T`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SO-8 (KiCad packages3D, STEP)
- 3D model files: `max31855tasa-t-etched.step` / `max31855tasa-t-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `max31855tasa-t.step` / `max31855tasa-t.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Analog Devices Inc Maxim Integrated datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603034619721621504) (13 pp, sha256 `0da8c21e66d26950`, retrieved 2026-10-18, tier: lcsc)
- **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/max31855tasa-t-datasheet.pdf)