Texas Instruments TPS70451PWP

Overview

TPS70451PWP from Texas Instruments is a dual-output, low-dropout voltage regulator IC delivering fixed 3.3 V (1 A) and 1.8 V (2 A) outputs with integrated power-on reset (RESET), manual reset (MR), and dual open-drain power-good (PG1/PG2) indicators. It uses PMOS pass elements for ultralow quiescent current (185 µA typ) and operates across –40°C to +125°C in split-voltage systems such as DSP/FPGA core-I/O power domains.

For engineers reviewing the TPS70451PWP datasheet, TPS70451PWP pinout, TPS70451PWP application, or TPS70451PWP equivalent, key selection considerations include independent enable control (EN1/EN2), 120-ms RESET delay, 95% output voltage trip threshold for PG signals, dropout voltage of 160 mV at 1 A (regulator 1), and compatibility with 47-µF low-ESR ceramic output capacitors.

Technical Context

The TPS70451PWP integrates two independent LDO regulators with separate input pins (VIN1/VIN2), enabling flexible power sequencing and source isolation. Regulator 1 (3.3 V/1 A) and regulator 2 (1.8 V/2 A) each feature dedicated feedback sense inputs (VSENSE1/VSENSE2), undervoltage lockout (UVLO), and thermal shutdown protection.

Its supervisory circuitry includes an active-low open-drain RESET output with 120-ms delay after VIN1 exceeds 2.65 V and MR is high-impedance, plus dual PG outputs asserting low when respective outputs fall below 95% of nominal voltage. The device draws only 2 mA total in sleep mode when both EN1 and EN2 are high.

Key Specifications

Pinout & Package

TPS70451PWP is housed in a 24-pin HTSSOP package (PWP) with exposed thermal pad (PowerPAD™) for enhanced heat dissipation. Pin numbering follows top-view orientation with pin 1 at bottom-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output LDO regulator applications.

Compared with TPS70458PWP and TPS70448PWP, the TPS70451PWP provides optimal voltage pairing for modern 1.8-V digital logic cores while maintaining identical sequencing, supervision, and thermal performance - making it the preferred choice for FPGA, DSP, and application processor designs.

Availability

TPS70451PWP is available at Aetrix Electronics and suitable for industrial automation, embedded computing, and programmable logic applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TPS70451PWP 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 and embedded processing technologies, with over 90 years of innovation in power management ICs.

The TPS704xx family was designed specifically for split-rail digital systems requiring tightly regulated, independently controlled dual outputs with integrated power supervision - targeting DSP, FPGA, and microprocessor applications.

FAQ

What are the output voltage options supported by the TPS70451PWP?

The TPS70451PWP provides fixed dual outputs: 3.3 V ±2% at up to 1 A (regulator 1) and 1.8 V ±2% at up to 2 A (regulator 2). These voltages are factory-trimmed and do not require external feedback resistors. The device belongs to the TPS704xx family, which also includes variants with 3.3-V/1.2-V, 3.3-V/1.5-V, and 3.3-V/2.5-V output combinations - but the TPS70451PWP itself is strictly 3.3 V / 1.8 V.

How does the TPS70451PWP achieve ultralow quiescent current?

The TPS70451PWP achieves 185 µA typical quiescent current using PMOS pass transistors instead of conventional PNP elements. Because the PMOS gate is voltage-driven, its bias current remains nearly constant across the full 0–1 A and 0–2 A output load ranges - unlike bipolar-based LDOs whose base current scales with load. This architecture also enables 2 mA total standby current when both EN1 and EN2 are high.

What is the function of the VSENSE1 and VSENSE2 pins on the TPS70451PWP?

On the TPS70451PWP, VSENSE1 (pin 21) and VSENSE2 (pin 16) are high-impedance feedback inputs that monitor the regulated output voltages. For fixed-output operation, they must be connected directly to VOUT1 and VOUT2 respectively - ideally with short, low-noise traces. These pins feed internal error amplifiers that maintain regulation accuracy; improper routing (e.g., long traces or shared return paths) can introduce noise and cause instability.

Can the TPS70451PWP be used with ceramic output capacitors?

Yes, the TPS70451PWP is explicitly designed to be stable with 47-µF low-ESR ceramic output capacitors on both VOUT1 and VOUT2. Its internal compensation eliminates the need for high-ESR tantalum or aluminum electrolytic capacitors. Using ceramics improves reliability, reduces size, and enhances transient response - critical for FPGA and DSP applications where rapid load steps occur.

What is the purpose of the GND/HEATSINK pins on the TPS70451PWP package?

TPS70451PWP features four dedicated GND/HEATSINK pins (1, 12, 13, 24) that electrically connect to the exposed thermal pad on the underside of the HTSSOP-24 (PWP) package. These pins serve dual roles: providing low-impedance ground return paths for both regulators and conducting heat from the die into the PCB copper thermal plane. Proper soldering of all four pins to a minimum 4-layer PCB with 1 oz. copper and a 4-in × 4-in ground plane is required to achieve rated 3.067 W power dissipation at TA = +25°C.