STMicroelectronics LD29080PT90R

Overview

LD29080PT90R from STMicroelectronics is a fixed-output 9.0 V, 800 mA low-dropout linear regulator in PPAK package, featuring 0.4 V typical dropout at full load, ±1% output voltage accuracy over temperature, and logic-controlled electronic shutdown. It delivers stable power for post-regulation in switching supplies and battery-powered systems requiring precise 9 V rail with minimal headroom.

For engineers reviewing the LD29080PT90R datasheet, LD29080PT90R pinout, LD29080PT90R application, or LD29080PT90R equivalent, key selection criteria include dropout voltage at 800 mA, thermal resistance (RthJC = 8 °C/W), quiescent current vs. load, output noise (330 µVRMS), and inhibit input compatibility with 2 V logic-high threshold.

Technical Context

The LD29080PT90R implements a high-accuracy bandgap reference with internal current and thermal limiting, enabling robust operation up to 125 °C junction temperature. Its fixed 9.0 V output is trimmed at 25 °C to ±1%, with load regulation of ≤1.0% across 10–800 mA and line regulation of ≤0.5% over VI = 10–13 V.

It integrates an inhibit function requiring ≥2 V on the INHIBIT pin for ON-mode operation; the pin is not internally pulled up. Dropout voltage remains ≤0.7 V at 800 mA and −40 to 125 °C, while supply voltage rejection reaches 43–57 dB at 120 Hz under 400 mA load.

Key Specifications

Pinout & Package

LD29080PT90R uses the PPAK (Power Package) thermally enhanced surface-mount package (6-pin, 6.0 × 6.6 mm body, 9.35–10.1 mm height), optimized for high-current LDO applications with low thermal resistance (RthJC = 8 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6209B902MR-G and NCP1117ST90T3G, LD29080PT90R uniquely combines 800 mA capability, 0.4 V ultra-low dropout, and 8 °C/W junction-to-case thermal resistance in PPAK-enabling higher power density and lower thermal overhead in industrial and automotive systems.

Availability

LD29080PT90R is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive infotainment systems, and portable test equipment requiring stable component supply with guaranteed long-term production continuity.

Supply support for LD29080PT90R 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

STMicroelectronics is a global semiconductor leader designing and manufacturing silicon solutions for automotive, industrial, and consumer applications, with strong emphasis on power management and reliability.

LD29080PT90R belongs to ST's high-accuracy, medium-current LDO family engineered for post-regulation in noise-sensitive and thermally constrained systems-including automotive body electronics and industrial automation.

FAQ

What is the minimum input voltage required for regulation at 800 mA output?

The LD29080PT90R requires VI ≥ VO + VDROP = 9.0 V + 0.4 V = 9.4 V (typical) to maintain regulation at 800 mA. At worst case (0.7 V dropout), VI must be ≥9.7 V. Input voltage must stay within 10–13 V per datasheet operating range to avoid automatic shutdown above 14 V.

Can the INHIBIT pin be left unconnected?

No. The INHIBIT pin is not internally pulled up; leaving it floating risks undefined operation. To ensure ON mode, it must be actively driven to ≥2 V (e.g., via MCU GPIO or resistor to VI). For permanent enable, connect directly to VI through a 10 kΩ series resistor to limit current.

Is a minimum load current required, and why?

Yes - a minimum load of 2 mA is required across −40 to 125 °C to prevent output voltage rise caused by internal leakage current. This is not optional: without it, VO may exceed 9.09 V (spec max), risking overvoltage stress on downstream components.

How does thermal performance compare between PPAK and DPAK packages?

Both PPAK and DPAK share identical RthJC = 8 °C/W and RthJA = 100 °C/W per datasheet Table 4. However, PPAK's smaller footprint (6.0 × 6.6 mm vs. DPAK's 6.0 × 6.2 mm) and exposed thermal pad allow superior PCB copper pour integration, yielding lower practical board-level thermal resistance in real layouts.