Texas Instruments TPS26612DDFR

Overview

TPS26612DDFR from Texas Instruments is a universal ±20 mA / 4–20 mA current loop protector with integrated bipolar 32-mA current limit, ±50-V operating voltage, 7.5-Ω typical R_ON, and EN pin control. It protects analog outputs and two-wire transmitters against input/output miswiring, surge (IEC61000-4-5), and EFT (IEC61000-4-4), and supports extended 5-s overload expiry for first fault events.

For engineers reviewing the TPS26612DDFR datasheet, TPS26612DDFR pinout, TPS26612DDFR application, or TPS26612DDFR equivalent, this device is selected for power supply protection in 2-wire transmitters and analog output modules where latch-off response, enable-controlled shutdown, and robust ±50-V field-side tolerance are required.

Technical Context

The TPS26612DDFR implements a bidirectional pass FET with configurable MODE pin logic to select fixed 32-mA current limit, 2× I_OL startup mode, or extended 5-s overload timer (t_{AR_dis}). Its fast-trip comparator responds within 5 µs to short-circuit or hot-plug transients, independent of the slower current-limit loop.

It features dual-supply operation (±2.25 V to ±20 V) or unipolar supply (4 V to 30 V), EN-controlled turn-on/off with 120-µs delay, SGOOD open-drain health indicator, and output overvoltage protection threshold at (+Vs)+1.0 V to (+Vs)+1.5 V - distinct from other TPS2661x variants.

Key Specifications

Pinout & Package

TPS26612DDFR uses an 8-pin SOT-23-THN (DDF) package measuring 2.9 mm × 1.6 mm, enabling high-density analog I/O module layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current loop protection applications.

Compared with TPS26611DDFR and TPS26614DDFR, the TPS26612DDFR uniquely provides 5-second extended overload expiry for transmitter startup while retaining latch-off behavior - making it the only variant qualified for power supply protection in 2-wire transmitters per TI's device comparison table.

Availability

TPS26612DDFR is available at Aetrix Electronics and suitable for factory automation PLCs, HVAC controllers, motor drive feedback systems, and two-wire transmitter designs requiring stable component supply across multi-year production cycles.

Supply support for TPS26612DDFR 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 specializing in analog, embedded processing, and power management ICs for industrial, automotive, and communications markets.

The TPS2661x family was designed specifically for robust current loop protection in industrial process automation - addressing miswiring, surge, EFT, and HART compatibility in analog input/output and sensor transmitter interfaces.

FAQ

What is the primary function of the TPS26612DDFR in an industrial current loop system?

The TPS26612DDFR serves as a universal current loop protector for ±20 mA and 4–20 mA analog signals. It safeguards downstream circuitry from field-side faults including input/output miswiring, ±50-V transients, and overload conditions. Its integrated 32-mA current limit, 5-s extended overload timer, and EN-controlled shutdown make it especially suited for protecting power supplies in two-wire sensor transmitters - a key differentiator from other TPS2661x variants. The TPS26612DDFR ensures signal integrity while minimizing board space and external protection components.

How does the MODE pin affect overload behavior in the TPS26612DDFR?

The MODE pin on the TPS26612DDFR configures three distinct overload responses: grounding selects standard 32-mA current limiting; leaving floating enables 2× I_OL (64 mA) for startup; and connecting to 180 kΩ pulls up enables both 2× I_OL and extended 5-s expiry time (t_{AR_dis}). This last mode is critical for powering two-wire transmitters that draw high inrush current during initialization. Unlike TPS26610/13, the TPS26612DDFR does not support loop power mode, but its MODE-driven extended timer is unique to its transmitter protection role.

What is the significance of the TPS26612DDFR's output overvoltage protection threshold being (+Vs)+1.0 V to (+Vs)+1.5 V?

The TPS26612DDFR's output overvoltage lockout (OVLO) threshold is intentionally set higher than other TPS2661x variants - which use (+Vs)+0.05 V to (+Vs)+0.30 V - to accommodate the wider voltage swing expected at analog output nodes. This prevents false triggering during normal operation of voltage-output stages while still protecting against dangerous rail-to-rail miswiring. The elevated threshold ensures robustness in analog output modules where OUT may swing near +Vs during dynamic load changes, a design choice confirmed in TI's Device Comparison Table and Electrical Characteristics section.

Can the TPS26612DDFR be used in unipolar 4–20 mA systems, and how is –Vs handled?

Yes, the TPS26612DDFR supports unipolar 4–20 mA operation by connecting the –Vs pin to system GND. In this configuration, the device blocks reverse current flow (OUT → IN) and maintains full ±50-V tolerance on the IN pin. The +Vs pin accepts 4 V to 30 V, enabling compatibility with common industrial supply rails. All protection features - including OVLO, UVLO, fast-trip, and SGOOD - remain fully functional. This unipolar setup is explicitly validated in TI's Functional Block Diagram (Figure 8-2) and Recommended Operating Conditions table.

How does the TPS26612DDFR's fast-trip response differ from its standard current-limiting behavior?

Standard current limiting in the TPS26612DDFR regulates output current at ~32 mA with a 30–55 µs response time, suitable for sustained overloads. In contrast, the fast-trip circuit activates within 5 µs when current exceeds ±120 mA (MODE = GND) or ±240 mA (MODE = floating), forcibly turning off the internal FET to suppress short-circuit energy before thermal damage occurs. After 50 µs, the device re-enables slowly to allow the current-limit loop to regain control - a dual-layer protection strategy documented in Section 8.3.1 and Timing Requirements Table 7.6. This behavior is hardware-asserted and independent of MODE pin state.