Texas Instruments TPS2231RGPR

Overview

TPS2231RGPR from Texas Instruments is a single-slot ExpressCard™ power interface switch IC that distributes and regulates 3.3 V, 1.5 V, and AUX power rails to ExpressCard|34/|54 sockets with integrated current limiting, thermal shutdown, and undervoltage lockout. It supports notebook and desktop host systems requiring compliant hot-plug power sequencing for PCI Express or USB-based ExpressCards.

For engineers reviewing the TPS2231RGPR datasheet, TPS2231RGPR pinout, TPS2231RGPR application, or TPS2231RGPR equivalent, key selection criteria include its 24-pin PowerPAD™ HTSSOP package, dual-rail current-limiting (1.3 A @ 3.3VOUT, 650 mA @ 1.5VOUT), PERST/RCLKEN timing coordination, and ExpressCard™ compliance per SLVS536A.

Technical Context

The TPS2231RGPR implements three independent MOSFET power switches - one each for 3.3VIN→3.3VOUT, 1.5VIN→1.5VOUT, and AUXIN→AUXOUT - each with internal current-sense circuitry, thermal foldback, and discharge FETs. Its control logic interprets CPPE/CPUSB card-present signals, SHDN/STBY mode inputs, and SYSRST to manage rail sequencing, standby states, and PERST assertion timing.

It integrates ExpressCard™-specific functions including RCLKEN as bidirectional reference clock enable, PERST generation with voltage-tolerance-based delay (500 ns–20 ms), and UVLO thresholds (2.6–2.9 V on 3.3VIN/AUXIN; 1.0–1.25 V on 1.5VIN). All outputs feature open-drain OC status reporting and are TTL-logic compatible.

Key Specifications

Pinout & Package

TPS2231RGPR uses a 24-pin PowerPAD™ HTSSOP (PWP) package with exposed thermal pad soldered to PCB ground plane for optimal thermal performance (θ_JA = 33.19 mW/°C; P_D = 3153 mW at T_A = 25°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS2231PWPR, the TPS2231RGPR offers 4.5× higher thermal power handling and optimized pinout for high-current routing; compared with TPS2236DAPR, it provides single-slot functionality in a smaller footprint with simpler control logic and lower system-level integration effort.

Availability

TPS2231RGPR is available at Aetrix Electronics and suitable for notebook computers, desktop computers, and industrial embedded systems requiring stable component supply, ExpressCard™ compliance, and long-term lifecycle support.

Supply support for TPS2231RGPR 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 power management technologies with over 50 years of innovation in high-reliability interface solutions.

The TPS2231RGPR belongs to TI's ExpressCard™ power interface product line, designed specifically to simplify host-side implementation of ExpressCard|34 and ExpressCard|54 slots while ensuring full specification compliance and robust fault protection.

FAQ

What is the primary function of the TPS2231RGPR in an ExpressCard host system?

The TPS2231RGPR serves as the dedicated power interface switch for single-slot ExpressCard|34 or ExpressCard|54 host systems. It manages distribution of 3.3 V, 1.5 V, and AUX power rails to the card socket, enforces current limits, sequences power-up/down, generates PERST and RCLKEN signals per ExpressCard™ specifications, and detects card presence via CPPE/CPUSB inputs. The TPS2231RGPR integrates all required protection and timing functions into one IC.

How does the TPS2231RGPR handle overcurrent and thermal faults?

The TPS2231RGPR monitors each output rail (3.3VOUT, 1.5VOUT, AUXOUT) with internal current-sense circuitry. Upon detecting overcurrent, it limits output current to a steady-state value (e.g., 1.3 A for 3.3VOUT) and asserts the open-drain OC pin after a 6–20 ms deglitch delay. Simultaneously, thermal shutdown activates at 155–165°C junction temperature with 10°C hysteresis, turning off all power switches until cooling occurs. The TPS2231RGPR combines both protections to prevent damage during shorts or overload conditions.

What is the role of RCLKEN in the TPS2231RGPR, and how does it interact with PERST?

RCLKEN in the TPS2231RGPR is a bidirectional pin that functions as both an output (power-good indicator to host clock driver) and an input (reset hold control). On power-up, RCLKEN remains low until all output rails stabilize within tolerance, then transitions high - triggering an internal timer that delays PERST de-assertion. If externally held low, RCLKEN prevents PERST de-assertion, enabling host-controlled reset timing. This precise hardware coordination between RCLKEN and PERST is essential for ExpressCard™ compliance and is implemented autonomously within the TPS2231RGPR.

Can the TPS2231RGPR support both USB and PCI Express ExpressCards in the same slot?

Yes, the TPS2231RGPR natively supports both USB and PCI Express ExpressCards through dedicated CPUSB and CPPE inputs. When either input is pulled low by an inserted card, the device enters Card Inserted mode and enables the appropriate rails: CPPE low activates 3.3 V and 1.5 V for PCIe operation; CPUSB low enables 3.3 V and AUX for USB operation. The TPS2231RGPR automatically configures rail states and timing without host software involvement, ensuring correct power delivery for either card type.

What are the critical voltage thresholds and timing parameters that define TPS2231RGPR ExpressCard™ compliance?

Key ExpressCard™-defined parameters for the TPS2231RGPR include: 3.3VIN and AUXIN UVLO thresholds (2.6–2.9 V), 1.5VIN UVLO (1.0–1.25 V), PERST assertion delay upon rail dropout (≤500 ns), PERST de-assertion delay after stabilization (4–20 ms), and output rise/fall times (0.05–6 ms) controlled by external capacitance. These values - verified in the SLVS536A datasheet - ensure interoperability with ExpressCard™ modules and are enforced entirely in hardware by the TPS2231RGPR.