STMicroelectronics LD29080DT90R

Overview

LD29080DT90R from STMicroelectronics is a fixed-output 9.0 V, 800 mA low-dropout linear regulator in DPAK package, featuring 400 mV 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, low-noise 9 V rails.

For engineers reviewing the LD29080DT90R datasheet, LD29080DT90R pinout, LD29080DT90R application, or LD29080DT90R equivalent, this page provides verified electrical specs, thermal performance data, real-world use cases, and validated alternative options - all grounded in ST's production-grade documentation (DocID10918 Rev 9).

Technical Context

The LD29080DT90R implements a high-accuracy bandgap reference with internal current and thermal limiting, enabling robust operation across –40 °C to +125 °C ambient. Its fixed 9.0 V output is trimmed to ±1% at 25 °C and maintains ±1.25% tolerance over full temperature and load range (10–800 mA).

It features an inhibit input (INHIBIT pin) requiring ≥2 V to enable regulation; below 0.8 V it enters low-quiescent shutdown (130–180 µA). Dropout voltage remains ≤0.7 V up to 800 mA, supporting operation with only 9.7 V input at full load.

Key Specifications

Pinout & Package

DPAK (TO-252-3) package: surface-mount, exposed thermal pad, 3-pin configuration optimized for thermal performance and PCB assembly reliability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD29080DT90R, LD2980DT90R offers improved ESD immunity without trade-offs, while TLV1117-90CDT requires larger input headroom and delivers lower accuracy - making the ST part optimal for noise- and space-constrained 9 V systems.

Availability

LD29080DT90R is available at Aetrix Electronics and suitable for industrial control I/O modules, portable test equipment, power supply post-regulation, and legacy voltage translation requiring stable component supply and long-term manufacturability.

Supply support for LD29080DT90R 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 headquartered in Geneva, Switzerland, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.

The LD29080 series belongs to ST's high-accuracy, medium-current LDO portfolio, engineered specifically for post-regulation, battery-powered, and noise-sensitive applications where dropout, accuracy, and thermal efficiency are critical.

FAQ

What is the minimum input voltage required for LD29080DT90R to regulate at full 800 mA load?

The LD29080DT90R requires a minimum input voltage of 9.4 V to maintain regulation at 800 mA, based on its typical 0.4 V dropout voltage (9.0 V + 0.4 V). At worst-case 0.7 V dropout, 9.7 V input is needed. Input below 9 V risks dropout and unregulated output.

Does LD29080DT90R require an external pull-up resistor on the INHIBIT pin?

Yes - the INHIBIT pin is not internally pulled up. To ensure reliable ON-mode operation, it must be connected to a voltage ≥2 V (e.g., via a 10–100 kΩ resistor to VI). Leaving it floating may cause erratic enable/disable behavior or increased quiescent current.

Can LD29080DT90R be used without a minimum load current?

No - a minimum load of 2 mA is required across the operating temperature range to prevent output voltage rise caused by internal leakage current. This is specified in ST's datasheet (Note 4, Table 5–11); omitting the load may result in output exceeding 9.09 V.

How does thermal performance differ between DPAK and PPAK packages for LD29080DT90R?

Both DPAK and PPAK share identical R_thJC = 8 °C/W and R_thJA = 100 °C/W values per ST's datasheet. Their thermal performance is functionally equivalent under identical PCB layout conditions - differing only in leadframe geometry and tape/reel packaging, not thermal capability.