Texas Instruments TMP303FDRLT

Overview

TMP303FDRLT from Texas Instruments is a factory-programmed temperature switch with fixed trip window (0°C to 80°C), push-pull active-high output, ±0.2°C typical trip accuracy from –40°C to 125°C, 5 μA maximum quiescent current, and 1.4 V to 3.6 V supply range - used in battery thermal protection and wireless heat detectors where autonomous, low-power overtemperature signaling is required.

For engineers reviewing the TMP303FDRLT datasheet, TMP303FDRLT pinout, TMP303FDRLT application, or TMP303FDRLT equivalent, key selection criteria include factory-set TH = 80°C trip point, selectable 1/2/5/10°C hysteresis via HYSTSET0/HYSTSET1 pins, SOH test-enable functionality, SOT-563 micropackage footprint (1.60 × 1.60 × 0.6 mm), and guaranteed operation down to 1.4 V for coin-cell compatibility.

Technical Context

The TMP303FDRLT implements a fully integrated analog temperature sensor core with comparator-based trip logic, programmable hysteresis decoder (HYSTSET0/HYSTSET1), and push-pull output driver - all operating without external components or microcontroller intervention. Its trip window is permanently configured at wafer level to TL = 0°C / TH = 80°C per device option table.

Hysteresis selection uses two digital input pins tied to VS or GND to set 1°C, 2°C, 5°C, or 10°C hysteresis; the SOH pin provides test-mode override by forcing OUT high regardless of sensed temperature. Power-up behavior asserts OUT = high for up to 35 ms before settling based on ambient temperature relative to the fixed trip window.

Key Specifications

Pinout & Package

SOT-563 (DRL) package: 1.60 mm × 1.60 mm × 0.6 mm body, 6-pin micropackage with exposed pad for thermal coupling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6511AXRD+T and LM75BIMM/NOPB, the TMP303FDRLT uniquely delivers factory-set 0°C–80°C window, sub-2°C accuracy across full range, and <5 μA operation at 1.4 V - making it optimal for maintenance-free, battery-critical thermal cutoffs where simplicity and longevity are primary design goals.

Availability

TMP303FDRLT is available at Aetrix Electronics and suitable for battery thermal protection, wireless heat detectors, consumer electronics thermal guard, and industrial fan control requiring stable component supply, long-lifecycle assurance, and consistent parametric performance across production lots.

Supply support for TMP303FDRLT 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 designing analog ICs, embedded processors, and connectivity solutions for industrial, automotive, and personal electronics markets.

The TMP303FDRLT belongs to TI's precision analog temperature switch product line, engineered specifically for autonomous, ultra-low-power thermal monitoring in space-constrained, battery-operated systems where reliability and zero-software intervention are mandatory.

FAQ

What is the factory-configured trip temperature window for TMP303FDRLT?

The TMP303FDRLT is factory-programmed with a fixed trip window of TL = 0°C and TH = 80°C. This configuration is permanent and cannot be altered in the field. The device asserts its active-high OUT signal when temperature exceeds 80°C and returns low only after crossing back below (80°C – hysteresis), where hysteresis is set via HYSTSET0/HYSTSET1 pins. No calibration or programming is required for this specific trip point.

Can TMP303FDRLT operate from a single 1.5 V alkaline battery?

Yes, TMP303FDRLT supports supply voltages from 1.4 V to 3.6 V, making it compatible with fresh 1.5 V alkaline cells (nominal 1.5 V, initial ~1.6 V, end-of-life ~0.9 V). Operation is guaranteed down to 1.4 V, and quiescent current remains ≤8 μA across the full –40°C to 125°C range. For reliable long-term use, pair with a low-leakage 0.1 µF ceramic bypass capacitor placed adjacent to the VS pin.

How does the SOH pin function in TMP303FDRLT?

The SOH (Set Output High) pin on TMP303FDRLT is a digital input with an internal 100 kΩ pulldown resistor. When left floating or grounded, it has no effect on device operation. When pulled high (≥0.7 × VS), it forces the OUT pin to logic high immediately - independent of measured temperature or hysteresis settings. This enables hardware-level functional testing of the output path during manufacturing or field diagnostics without thermal stimulus.

What hysteresis values are supported by TMP303FDRLT and how are they selected?

TMP303FDRLT supports four hysteresis values: 1°C, 2°C, 5°C, and 10°C. Selection is performed by connecting HYSTSET0 (Pin 1) and HYSTSET1 (Pin 6) to either GND or VS per TI's Table 1: GND/GND = 1°C, GND/VS = 2°C, VS/GND = 5°C, VS/VS = 10°C. These pins must be statically tied - no dynamic reconfiguration is possible after power-up. Hysteresis determines the temperature delta required for OUT to transition back to low after exceeding TH = 80°C.

Is a bypass capacitor required for stable operation of TMP303FDRLT?

Yes, TI strongly recommends a 0.1 µF X5R or X7R ceramic bypass capacitor placed as close as possible between VS (Pin 5) and GND (Pin 2). This capacitor suppresses supply noise and ensures clean power-up sequencing, especially critical given the device's 20–35 ms start-up delay and sensitivity to voltage transients. Omitting it may cause erratic OUT behavior or extended invalid output states during supply ramp-up.