Texas Instruments TPS2231MRGPT-1

Overview

TPS2231MRGPT-1 from Texas Instruments is a single-slot ExpressCard™ power interface switch that distributes and regulates 3.3 V, 1.5 V, and AUX power rails to ExpressCard|34/|54 sockets with integrated current limiting, thermal protection, and undervoltage lockout. It supports notebook and desktop computers requiring compliant hot-plug power sequencing for PCI Express or USB-based ExpressCard modules.

For engineers reviewing the TPS2231MRGPT-1 datasheet, TPS2231MRGPT-1 pinout, TPS2231MRGPT-1 application, or TPS2231MRGPT-1 equivalent, key selection criteria include its 24-pin PowerPAD™ HTSSOP package, 1.3 A 3.3VOUT continuous output, dual-input UVLO thresholds (2.6 V for 3.3VIN/1.5VIN, 2.6 V for AUXIN), and ExpressCard-compliant PERST/RCLKEN timing behavior under card insertion/removal.

Technical Context

The TPS2231MRGPT-1 implements three independent MOSFET power switches - one each for 3.3VIN→3.3VOUT, 1.5VIN→1.5VOUT, and AUXIN→AUXOUT - each with internal current-limit sensing, thermal shutdown (trip at 155–165°C), and discharge FETs for safe rail ramp-down. Its control logic interprets CPPE/CPUSB, SHDN, STBY, and SYSRST to manage six discrete power states: OFF, Shutdown, No Card, Standby, and Card Inserted.

It features tightly coupled power-good signaling: RCLKEN releases only after all outputs stabilize within tolerance, triggering a programmable delay before PERST de-assertion; PERST asserts immediately upon any rail falling below threshold or SYSRST activation. All logic inputs are TTL-compatible with internal AUXIN-referenced pullups.

Key Specifications

Pinout & Package

TPS2231MRGPT-1 is housed in a thermally enhanced 24-pin PowerPAD™ HTSSOP (PWP) package with exposed thermal pad. The package enables high-power dissipation (3153 mW at TA = 25°C) and requires soldering the PowerPAD to PCB ground for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ExpressCard power interface applications.

Compared with TPS2231PW, TPS2231MRGPT-1 delivers 4.5× higher power dissipation capability and tighter thermal resistance, enabling reliable operation in compact, fanless notebooks. Against TPS2236DAP, it provides optimized single-slot functionality without redundant circuitry, reducing solution cost by 28% and PCB area by 32%.

Availability

TPS2231MRGPT-1 is available at Aetrix Electronics and suitable for notebook computers, desktop add-in cards, and digital camera media adapters requiring stable component supply, ExpressCard compliance, and industrial-grade thermal resilience.

Supply support for TPS2231MRGPT-1 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 connectivity technologies, with over 50 years of innovation in power management ICs.

The TPS2231MRGPT-1 belongs to TI's ExpressCard power interface product line, designed specifically to simplify compliance with PCMCIA ExpressCard|34/|54 specifications while minimizing external components and thermal design complexity.

FAQ

What is the primary function of the TPS2231MRGPT-1 in an ExpressCard system?

The TPS2231MRGPT-1 serves as the dedicated power interface switch for single-slot ExpressCard|34 or ExpressCard|54 sockets. It manages distribution of 3.3 V, 1.5 V, and AUX power rails with integrated current limiting, thermal protection, and ExpressCard-compliant signaling (PERST, RCLKEN, CPPE, CPUSB). Its core function is to ensure safe, sequenced, and standards-compliant hot-plug power delivery to ExpressCard modules in notebook and desktop platforms.

Does the TPS2231MRGPT-1 support both PCI Express and USB-based ExpressCard modules?

Yes, the TPS2231MRGPT-1 explicitly supports both interface types via dedicated CPPE (Card Present for PCI Express) and CPUSB (Card Present for USB) inputs. These TTL-compatible pins detect card insertion and determine module type, enabling appropriate power sequencing and signaling behavior per the ExpressCard specification. Both signals are internally pulled up to AUXIN, simplifying host-side interface design.

How does the TPS2231MRGPT-1 handle overcurrent and thermal faults?

The TPS2231MRGPT-1 implements per-rail current limiting with fast response (<150 µs) and thermal shutdown at 155–165°C. When overcurrent occurs on any rail (3.3VOUT, 1.5VOUT, or AUXOUT), the OC pin asserts low (open-drain) after a 6–20 ms deglitch delay. Simultaneously, the affected switch latches off until fault clears and power cycles. Thermal shutdown disables all outputs and activates discharge FETs to safely ramp down voltages.

What is the role of the RCLKEN pin on the TPS2231MRGPT-1?

RCLKEN on the TPS2231MRGPT-1 is a bidirectional pin serving two roles: as an output, it transitions high (after internal discharge FET release) once all power rails stabilize, signaling host clock drivers that power is stable; as an input, holding it low delays PERST de-assertion, allowing synchronization with host clock enable timing. It must never be driven high externally - only pulled low or left floating.

Can the TPS2231MRGPT-1 operate without a 1.5VIN supply?

Yes - the TPS2231MRGPT-1 can operate with only AUXIN and 3.3VIN present. In this configuration, the 1.5VOUT switch remains disabled (UVLO threshold unmet), but 3.3VOUT and AUXOUT remain functional. This supports ExpressCard modules requiring only 3.3 V and AUX power, such as certain USB-based peripherals. The device enters Standby mode if STBY is asserted, keeping AUXOUT active while disabling 3.3VOUT and 1.5VOUT.