Texas Instruments TMP121AQDBVREP

Overview

TMP121AQDBVREP from Texas Instruments is a radiation-hardened, extended-temperature digital temperature sensor with SPI-compatible serial interface, ±1.5°C accuracy from –25°C to 85°C, 12-bit + sign resolution (0.0625°C), and low quiescent current (50 µA max) in SOT23-6 package - used for thermal protection in space-grade power-supply monitoring and satellite onboard computer systems.

For engineers reviewing the TMP121AQDBVREP datasheet, TMP121AQDBVREP pinout, TMP121AQDBVREP application, or TMP121AQDBVREP equivalent, this page delivers verified electrical specs, thermal performance limits, SPI timing constraints, shutdown behavior, and qualified alternatives for high-reliability aerospace thermal sensing deployments.

Technical Context

The TMP121AQDBVREP integrates a silicon diode-based temperature sensor, sigma-delta A/D converter, oscillator, control logic, and SPI-compatible serial interface - all on a single die. It performs continuous temperature conversion while CS is high, latching data on CS falling edge for readout via SO on SCK falling edges.

Its thermal sensing relies on the die flag's thermal coupling to Pin 2 (GND), making GND the primary thermal path; NC pins (1 and 3) must be left floating or tied to GND. Conversion time is 240–320 ms (12-bit), with a 480–640 ms period between starts, enabling predictable low-power thermal sampling in radiation-tolerant systems.

Key Specifications

Pinout & Package

SOT23-6 (DBV) package with 1.45 mm max height, moisture sensitivity level 2 (260°C peak reflow), RoHS-compliant NiPdAu lead finish, and Q3 pin-1 quadrant orientation in tape.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TMP121AQDBVREP, TMP123AQDBVREP offers identical form factor but inferior thermal path fidelity, while MAX6627ESA+ trades radiation hardening and resolution for I²C convenience and broader commercial availability - making TMP121AQDBVREP the sole choice for mission-critical thermal sensing where accuracy, reliability, and thermal coupling are non-negotiable.

Availability

TMP121AQDBVREP is available at Aetrix Electronics and suitable for aerospace power-supply monitoring, satellite onboard computer thermal protection, and radiation-tolerant battery management systems requiring stable component supply across extended product lifecycles.

Supply support for TMP121AQDBVREP 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 leader specializing in analog, embedded processing, and high-reliability components, with decades of heritage in space-grade analog ICs and precision sensing solutions.

The TMP121-EP product line was designed specifically for extended-temperature, radiation-tolerant applications in defense, aerospace, and high-reliability industrial systems - emphasizing accuracy stability, low power, and qualification pedigree over consumer-grade cost targets.

FAQ

What is the absolute maximum operating temperature for the TMP121AQDBVREP?

The TMP121AQDBVREP has an absolute maximum junction temperature of 150°C and operates continuously from –55°C to 150°C. Its specified accuracy range is –40°C to 125°C, and it is qualified per JEDEC standards including HAST and temperature cycling to ensure reliability under these extremes. The TMP121AQDBVREP maintains functional integrity up to its 150°C limit, though accuracy degrades beyond 125°C per published electrical characteristics.

Does the TMP121AQDBVREP require external components for basic operation?

No, the TMP121AQDBVREP requires no external components for core temperature measurement functionality. A 0.1 µF ceramic bypass capacitor between V+ and GND is recommended for supply stability during conversion bursts, but it is not mandatory for functionality. The TMP121AQDBVREP integrates the temperature-sensing diode, sigma-delta ADC, oscillator, and SPI interface on-die - eliminating need for external references, clocks, or signal conditioning circuitry.

How does the TMP121AQDBVREP handle thermal conduction for accurate measurements?

The TMP121AQDBVREP uses the die flag of its lead frame - thermally connected to Pin 2 (GND) - as the primary thermal path. This design makes GND the optimal mounting point for PCB thermal vias or copper pours to extract heat from the IC and match ambient or component temperature. Pins labeled NC (1 and 3) must be left floating or grounded to avoid perturbing this path. The TMP121AQDBVREP's 200°C/W θJA reflects this optimized conduction route, critical for accuracy in surface-mount thermal monitoring.

What SPI timing parameters define reliable communication with the TMP121AQDBVREP?

The TMP121AQDBVREP specifies minimum SCK period (t1) of 100 ns, maximum SCK-to-SO propagation delay (t2) of 30 ns, and CS setup time (t3) of 40 ns relative to first SCK edge. These values enable interoperability with standard MCU and FPGA SPI peripherals clocked up to 10 MHz. The TMP121AQDBVREP outputs data MSB-first on SCK falling edges, and the SO line enters high-impedance state 30 ns after CS rises - ensuring clean bus sharing in multi-device SPI configurations.

Is the TMP121AQDBVREP pin-compatible with the commercial TMP121 variant?

Yes, the TMP121AQDBVREP shares identical SOT23-6 (DBV) pinout, electrical interface, and register map with the commercial TMP121, including NC/GND/SO/CS/SCK/V+ assignments and SPI protocol behavior. However, the TMP121AQDBVREP adds radiation-hardened process, extended temperature qualification (–55°C to 150°C), enhanced DMS support, and controlled baseline manufacturing - making it a drop-in replacement in terms of layout and firmware, but not a generic substitute for non-space applications due to cost and availability constraints.