sensors

MAX31865

Every spec below is cited to the manufacturer datasheet. Pick your exact ordering code, compare the closest alternatives, then ask the assistant what it means for your design.

00 — Overview

What the MAX31865 family does

The MAX31865 is a resistance-to-digital converter optimized for platinum RTDs, handling 100Ω to 1kΩ sensors in 2-, 3-, and 4-wire configurations. It features a 15-bit ADC with 0.5°C total accuracy, 21ms conversion time, and ±45V input protection. The device includes integrated fault detection for open or shorted elements and supports SPI-compatible interfaces. Available in 20-pin TQFN and SSOP packages, it operates from -40°C to +125°C. Engineers use this component in industrial and medical equipment to simplify temperature measurement designs while reducing system cost and design cycle time.

Next step

Start building with MAX31865 → Every number above is cited straight from the datasheet — ask what they mean for your design, and the assistant answers from the same source documents.

01 — Key specifications

MAX31865 datasheet parameters

Parameter	Min	Typ	Max	Conditions	Source
quiescent current	—	2 mA	3.5 mA	Bias on, active conversion; (note 6); Electrical Characteristics	ADI datasheet, p. 3 — Electrical Characteristics (continued)
output current	200 µA	—	5.75 mA	Electrical Characteristics	ADI datasheet, p. 3 — Electrical Characteristics (continued)
supply voltage range	3 V	—	3.6 V	VDD and DVDD recommended DC operating conditions	ADI datasheet, p. 2 — Recommended DC Operating Conditions
cmrr	—	90 dB	—	common; Electrical Characteristics	ADI datasheet, p. 3 — Electrical Characteristics (continued)
operating temperature	-40 °C	—	125 °C	Operating Temperature Range	ADI datasheet, p. 2
input capacitance	—	6 pF	—	Logic inputs; Electrical Characteristics	ADI datasheet, p. 3 — Electrical Characteristics (continued)
rise time	—	—	200 ns	(Note 9); AC Electrical Characteristics: SPI Interface	ADI datasheet, p. 4 — AC Electrical Characteristics: SPI Interface
output voltage low	—	—	400 mV	IOUT = 1.6mA; Electrical Characteristics	ADI datasheet, p. 3 — Electrical Characteristics (continued)
sample rate	50 Hz	—	60 Hz	Automatic conversion mode, 50/60Hz filter select	ADI datasheet, p. 13

03 — Alternatives

Closest matches to MAX31865

SHT30-DIS 5.5× lower sample rate, 1.5× higher rise time, similar operating temperature

TMP102 13.8× lower sample rate, 2.0× lower input capacitance, 1.5× higher rise time

PGA302 5.7× higher output current, 3.2× higher quiescent current, 1.3× lower supply voltage range

LTR-308ALS-01 18.2× lower quiescent current, 5.5× lower sample rate, 1.9× lower operating temperature

DS18B20 2.0× lower quiescent current, 1.2× lower operating temperature, 1.2× higher supply voltage range

LSM6DS3TR-C 2.0× lower output voltage low, 1.9× lower operating temperature, 1.8× lower supply voltage range

MAX31820 2.0× lower quiescent current, 1.2× lower operating temperature, similar supply voltage range

MAX31820MCR+ 2.0× lower quiescent current, 1.2× lower operating temperature, similar supply voltage range

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