Texas Instruments TMP390A2DRLT

Overview

TMP390A2DRLT from Texas Instruments is a dual-channel, resistor-programmable temperature switch providing independent overtemperature (hot) and undertemperature (cold) detection with ±3.0°C accuracy (−55°C to +130°C), 0.5 µA typical quiescent current at 25°C, and open-drain outputs in a 1.60 mm × 1.20 mm SOT-563 package. It enables thermal protection in space-constrained DC/DC converters and wireless infrastructure RRU modules.

For engineers reviewing the TMP390A2DRLT datasheet, TMP390A2DRLT pinout, TMP390A2DRLT application, or TMP390A2DRLT equivalent, key selection considerations include channel-specific trip point programmability via E96 resistors, hysteresis options (5°C/10°C/20°C), ultra-low power operation across 1.62–5.5 V supply, and in-system trip test functionality for manufacturing validation.

Technical Context

The TMP390A2DRLT implements two independent analog temperature sensing channels with digital comparator logic, each configured by external E96-series resistors on SETA (Channel A: +30°C to +124°C, 2°C steps) and SETB (Channel B: −50°C to +25°C, 5°C steps). Hysteresis is set globally-5°C or 10°C for both channels-or 20°C for Channel A only when SETB is grounded.

It operates in continuous sampling mode with 0.5 s update interval and 0.65 ms conversion time, entering standby between conversions to maintain 0.5 µA average current. The device features power-on reset at 1.5 V, supports separate VDDIO for output pull-up up to VDD + 0.3 V, and includes internal 125 kΩ pull-downs on SETA/SETB pins.

Key Specifications

Pinout & Package

SOT-563 (6-pin) package, 1.60 mm × 1.20 mm body size, 0.5 mm pitch - optimized for high-density PCB layouts in compact power electronics and RF modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TMP390A2DRLT, TMP392A2DRLT omits cold-temperature capability but retains identical power and package advantages for warm-alert use cases, while LMT01LPGM trades resistor-based flexibility for superior accuracy and digital output-requiring firmware support and sacrificing channel independence.

Availability

TMP390A2DRLT is available at Aetrix Electronics and suitable for DC/DC converters, wireless infrastructure RRUs, and power tool battery packs requiring stable component supply, long-term manufacturability, and guaranteed thermal performance across extended temperature ranges.

Supply support for TMP390A2DRLT 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 delivering analog and embedded processing solutions, with leadership in precision analog, power management, and signal chain technologies.

The TMP390A2DRLT belongs to TI's ultra-low-power temperature switch product line, designed specifically for thermal event detection and protection in space-constrained, battery-sensitive, and high-reliability applications such as telecom infrastructure and portable power systems.

FAQ

What is the accuracy specification of the TMP390A2DRLT over its full operating temperature range?

The TMP390A2DRLT provides ±3.0°C maximum trip point accuracy across −55°C to +130°C. Within the 0°C to +70°C range, accuracy improves to ±1.5°C. This A2-level grading is confirmed in the device's electrical characteristics table and applies under recommended operating conditions (VDD = 1.62 V to 5.5 V). The accuracy is independent of external resistor tolerance due to the device's ratiometric architecture.

How does the hysteresis configuration work on the TMP390A2DRLT, and what are the valid options?

The TMP390A2DRLT supports three hysteresis configurations: 5°C, 10°C for both channels (selected via SETB resistor value per Table 7-2), or 20°C exclusively for Channel A (enabled by grounding SETB). Hysteresis is applied as a fixed offset-subtracting from the hot trip point (Channel A) or adding to the cold trip point (Channel B)-to prevent output oscillation during slow thermal transitions. Resistor selection directly maps to hysteresis option per TI's published programming tables.

Can the TMP390A2DRLT operate from a 1.8 V supply, and what is its quiescent current at that voltage?

Yes, the TMP390A2DRLT operates across 1.62 V to 5.5 V, fully supporting 1.8 V nominal supplies. At 1.8 V and 25°C, its average quiescent current remains 0.5 µA typical, as specified in Section 6.5 of the datasheet. This ultra-low current is maintained across the entire supply range, enabling direct connection to low-voltage battery rails without regulation.

What is the purpose and implementation method of the trip test function on the TMP390A2DRLT?

The trip test function allows in-system validation of the TMP390A2DRLT's external components (SETA/SETB resistors, pull-up networks, PCB routing) without thermal chamber testing. To execute: apply a logic-high signal (≥0.8 × VDD) to SETA or SETB, causing the corresponding output (OUTA or OUTB) to assert low immediately. Removal of the test signal restores normal thermal monitoring. This feature is intended solely for production test-not functional operation-and does not alter programmed thresholds.

Is the TMP390A2DRLT pin-compatible with other devices in the TMP39x family, such as the TMP392A2DRLT?

Yes, the TMP390A2DRLT and TMP392A2DRLT share identical SOT-563 (DRL) packaging, pinout, and electrical interface-including SETA, SETB, GND, OUTB, VDD, and OUTA assignments. However, their functional behavior differs: TMP390A2DRLT implements Hot/Cold detection (Channel A = overtemp, Channel B = undertemp), while TMP392A2DRLT implements Hot/Warm detection (Channel B = mid-range warm alert). Board layout is interchangeable, but firmware and resistor selection must match the selected device's channel definition.