Analog Devices Inc./Maxim Integrated MAX6633MSA+T

Overview

MAX6633MSA+T from Maxim Integrated is a 12-bit + sign SMBus/I²C-compatible digital temperature sensor with programmable overtemperature alarm, 0.0625°C resolution, ±1°C accuracy (0°C to +50°C), and operation from -55°C to +150°C - used for PC thermal management and battery safety monitoring.

For engineers reviewing the MAX6633MSA+T datasheet, MAX6633MSA+T pinout, MAX6633MSA+T application, or MAX6633MSA+T equivalent, this page delivers verified functional identity, validated SO-8 pin mapping, confirmed SMBus timing compliance (10–100 kHz), real-world alarm configuration behavior, and direct alternative part comparisons grounded in register-level feature parity.

Technical Context

The MAX6633MSA+T integrates a bandgap-based PTAT sensor, 12-bit ADC, and SMBus/I²C slave interface in a single die. It performs continuous asynchronous temperature conversions every 500 ms and stores results in a read-only 16-bit temperature register (12 data bits + sign bit, LSB = 0.0625°C).

It supports Write Byte/Word and Read Byte/Word commands, uses a 3-bit pointer register to access internal registers, and implements shutdown mode via Configuration register bit D0 - reducing supply current to ≤30 µA while retaining last temperature value in the register.

Key Specifications

Pinout & Package

MAX6633MSA+T is housed in an 8-pin SO (Small Outline) package (package code S8-2), RoHS-compliant, with 1.27 mm lead pitch and standard JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital temperature sensor applications.

Compared with MAX6634MSA+T, MAX6633MSA+T offers higher bus density (16 vs. 8 devices) but no dual-threshold alarm; versus LM75BIMM/NOPB, it delivers 3× better resolution, tighter accuracy, and active power management - making it optimal for thermally constrained embedded systems requiring scalable, configurable sensing.

Availability

MAX6633MSA+T is available at Aetrix Electronics and suitable for PC thermal management, battery safety monitoring, and industrial motor drive thermal protection requiring stable component supply and long-term lifecycle assurance.

Supply support for MAX6633MSA+T includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and digital ICs for demanding industrial, computing, and communications applications.

The MAX6633MSA+T belongs to Maxim's high-accuracy digital temperature sensor family, engineered specifically for SMBus/I²C-based thermal monitoring in space-constrained, high-reliability systems where resolution, wide temperature range, and bus scalability are critical.

FAQ

What is the resolution and output format of the MAX6633MSA+T temperature register?

The MAX6633MSA+T provides 12-bit + sign temperature data stored in a 16-bit register, with 1 LSB = 0.0625°C. The value is encoded in two's-complement format - for example, 0x0C80 = +25.0000°C, 0xFFF8 = -0.0625°C. This format enables direct arithmetic interpretation by host firmware without additional sign-handling logic, and the MAX6633MSA+T outputs raw digital values, not analog voltage.

Does the MAX6633MSA+T support programmable temperature thresholds like the MAX6634/MAX6635?

No, the MAX6633MSA+T does not support programmable high/low temperature thresholds. Unlike the MAX6634MSA+T and MAX6635MSA+T, it lacks THIGH, TLOW, and THYST registers. Its sole alarm function is fixed-threshold overtemperature detection via external host polling of the temperature register - the MAX6633MSA+T relies entirely on the system controller to implement threshold logic and response.

What is the maximum number of MAX6633MSA+T devices that can share a single SMBus/I²C bus?

The MAX6633MSA+T supports up to 16 devices on one SMBus/I²C bus using its four hardware address pins (A0–A3). Each pin is independently tied to GND or VCC to generate a unique 4-bit address code, resulting in 2⁴ = 16 possible combinations. This capability is exclusive to the MAX6633MSA+T - the MAX6634MSA+T supports 8 devices (3 address pins), and the MAX6635MSA+T supports 4 (2 address pins).

Can the MAX6633MSA+T operate from a 3.3V supply, and what is its typical supply current?

Yes, the MAX6633MSA+T operates from +3.0V to +5.5V, including standard 3.3V rails. At VCC = +3.3V and TA = +25°C, its average operating current is 150 µA; peak current during conversion is 270–350 µA. In shutdown mode, current drops to ≤20 µA at +3.0V and ≤30 µA at +5.5V - confirming robust low-power operation essential for MAX6633MSA+T deployment in battery-backed systems.

Is the MAX6633MSA+T pin-compatible with the LM75 or other legacy temperature sensors?

No, the MAX6633MSA+T is not pin-compatible with the LM75 series. It uses an 8-pin SO package but assigns pins differently: LM75 has OS (open-drain output) and SDA/SCL/GND/VCC, whereas MAX6633MSA+T dedicates pins 3, 5, 6, and 7 to address inputs (A3–A0). Additionally, the MAX6633MSA+T lacks a dedicated OS output - alarm status must be polled via SMBus. Direct replacement would require PCB redesign and firmware updates.