Texas Instruments TPS2045P

Overview

TPS2045P from Texas Instruments is a 250 mA continuous-current, active-low-enable, high-side N-channel MOSFET power-distribution switch with 135 mΩ on-resistance (at 5 V), integrated current limiting (0.44 A typical short-circuit limit), thermal shutdown, and open-drain overcurrent flag - designed for USB port power control and hot-insertion applications in notebook PCs and peripherals.

For engineers reviewing the TPS2045P datasheet, TPS2045P pinout, TPS2045P application, or TPS2045P equivalent, this device delivers precise current-limited switching with controlled 2.5-ms rise time, undervoltage lockout (2.5 V threshold), and <10 µA standby supply current - critical for reliable bus-powered hub and peripheral power sequencing.

Technical Context

The TPS2045P implements an internal charge pump to drive the N-channel MOSFET gate above the source, enabling full enhancement down to 2.7 V input while maintaining low r_DS(on). Its current-sense FET architecture avoids series resistive losses and enables fast, accurate overload detection without external components.

Thermal protection activates at ~140°C junction temperature with ~20°C hysteresis, and the OC output remains asserted low during overcurrent or overtemperature faults. The active-low enable input is TTL/CMOS-compatible and disables bias to reduce supply current to ≤10 µA.

Key Specifications

Pinout & Package

TPS2045P is housed in an 8-pin plastic dual-in-line package (PDIP-P), with exposed leads for manual soldering and prototyping. Thermal resistance θ_JA is 106°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side current-limited power-switch applications.

Compared with TPS2045P, TPS2041BP offers identical protection and performance with reversed enable polarity - ideal for direct GPIO control without level-shifting. AP2171SG-13 trades OC reporting and thermal hysteresis for size and current headroom, making it appropriate only where fault diagnostics are secondary.

Availability

TPS2045P is available at Aetrix Electronics and suitable for USB peripheral design, industrial I/O modules, and notebook docking stations requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TPS2045P 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 ICs, with decades of expertise in USB and power-distribution solutions.

The TPS2045P belongs to TI's legacy current-limited power-switch family, engineered specifically for USB-compliant hot-plug power control - emphasizing inrush suppression, per-port fault isolation, and robust thermal management in compact packages.

FAQ

What is the enable logic polarity of the TPS2045P?

The TPS2045P features an active-low enable input (EN). A logic low on Pin 4 turns the high-side switch ON; a logic high disables the switch and reduces quiescent supply current to ≤10 µA. This matches common reset-active-low microcontroller GPIO configurations and simplifies direct connection without inverters.

Does the TPS2045P provide overcurrent reporting, and how is it implemented?

Yes, the TPS2045P provides overcurrent reporting via its open-drain OC pin (Pin 5), which pulls low during current-limit or thermal fault conditions. It requires an external pull-up resistor to a logic rail (e.g., 3.3 V or 5 V) and interfaces directly with MCU interrupt inputs - enabling real-time port-level fault detection in USB hubs and peripherals.

What is the maximum continuous output current rating for the TPS2045P?

The TPS2045P is rated for 250 mA continuous output current across its full operating ambient temperature range (–40°C to +85°C). This rating assumes proper PCB layout, adequate copper area for heat dissipation, and input voltage ≥2.7 V. Derating applies above 70°C ambient per the PDIP package's thermal characteristics.

How does the TPS2045P handle short-circuit events?

Upon detecting an overload exceeding ~0.44 A, the TPS2045P enters constant-current mode, regulating output current while reducing output voltage. If the fault persists and junction temperature reaches ~140°C, thermal shutdown disables the switch. After cooling ~20°C, it automatically recovers - cycling until the fault clears.

Can the TPS2045P operate from a 3.3 V supply, and what is its on-resistance at that voltage?

Yes, the TPS2045P operates from 2.7 V to 5.5 V. At 3.3 V input and 25°C, its typical r_DS(on) is 105 mΩ (max 150 mΩ at 125°C), resulting in ≤37.5 mV dropout at 250 mA - sufficient for low-voltage peripheral rails while maintaining robust current limiting and thermal response.