Texas Instruments LM71A1 MDA

Overview

LM71A1 MDA from Texas Instruments is a die-form digital temperature sensor with ±1.0°C accuracy over –25°C to +85°C, SPI interface, and 12-bit resolution. It operates from 2.7V to 5.5V, draws 240 µA typical active current, and is designed for embedded thermal monitoring in space-constrained ASIC or hybrid module integration.

For engineers reviewing the LM71A1 MDA datasheet, LM71A1 MDA pinout, LM71A1 MDA application, or LM71A1 MDA equivalent, key selection factors include its die-level form factor, GND-backside thermal path, A-step bond pad layout, and SPI-compatible serial output timing without external clocking.

Technical Context

The LM71A1 MDA implements a bandgap-based temperature-sensing core with successive-approximation ADC and SPI-compatible shift-register output logic. Its die integrates six bond pads with defined coordinates, fixed V+ and GND terminals, and dedicated CS/, SC, and SIO signals for full-duplex SPI communication.

It requires external pull-up on SIO for proper read operation and uses back-side GND connection for thermal reference and mechanical mounting. No internal voltage regulator or EEPROM is present-operation relies entirely on host-controlled SPI timing and stable supply rail.

Key Specifications

Pinout & Package

LM71A1 MDA is supplied as an unbonded die in A-step configuration, with aluminum (0.5% Cu) bond pads on nitride-passivated surface. No molded package - intended for flip-chip, wire-bond, or die-attach integration into custom assemblies.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar die-form digital temperature sensing applications.

Compared with MAX31875RHA+ and ADT7320TRZ, the LM71A1 MDA offers smallest physical footprint and direct back-side thermal anchoring, but requires custom die handling and host-managed SPI timing-making it optimal for volume ASIC co-packaging rather than board-level replacement.

Availability

LM71A1 MDA is available at Aetrix Electronics and suitable for motor drive thermal monitoring, industrial PLC module sensing, and optical transceiver housing requiring stable component supply and consistent die-level specifications across production lots.

Supply support for LM71A1 MDA 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

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The LM71A1 MDA belongs to TI's die-form temperature sensor product line, engineered specifically for integration into custom hybrid modules, ASIC packages, and space-constrained thermal management subsystems where surface-mount packages are impractical.

FAQ

What is the operating temperature range of the LM71A1 MDA?

The LM71A1 MDA is specified for operation from –25°C to +85°C ambient. Its ±1.0°C accuracy is guaranteed across this range, with no extended-range calibration or compensation required. The die's thermal response time is dominated by the host substrate; actual junction temperature tracking depends on back-side GND thermal interface quality. LM71A1 MDA does not include internal temperature compensation beyond factory-trimmed bandgap reference.

Does the LM71A1 MDA require external components for basic operation?

No external passive components are required for basic LM71A1 MDA operation. A stable 2.7–5.5V supply and host-driven SPI signals (CS/, SC, SIO) suffice. However, a pull-up resistor (~4.7 kΩ to V+) on SIO is recommended for reliable read timing, and clean power decoupling (e.g., 100 nF ceramic near V+/GND bond pads) is advised to maintain ±1.0°C accuracy under dynamic load conditions.

How is thermal connection established for the LM71A1 MDA?

The LM71A1 MDA establishes thermal connection via its bare silicon back side, metallized with GND. This surface must be bonded-using conductive epoxy, solder, or thermal interface material-to a thermally conductive substrate or heatsink. Mechanical pressure and low-thermal-resistance interface are essential; air gaps degrade accuracy. Front-side bond pads remain electrically isolated from thermal path, preserving signal integrity.

Can multiple LM71A1 MDA dies share a single SPI bus?

Yes, multiple LM71A1 MDA dies can share SC and SIO lines, but each requires a dedicated CS/ signal. The LM71A1 MDA has no internal address or ID register-chip select is the sole means of device selection. Host firmware must assert only one CS/ at a time and manage timing between transactions to avoid bus contention or incomplete reads.

Is the LM71A1 MDA RoHS compliant and lead-free?

Yes, the LM71A1 MDA die conforms to RoHS Directive 2011/65/EU and is lead-free. Bond pad metallization is aluminum with 0.5% copper; no lead-based solder or plating is used. Wafer fabrication and final test meet TI's standard environmental compliance protocols, and material declarations are available under TI's component compliance portal upon request for LM71A1 MDA.