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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

STMicroelectronics LDK120PU29R

Name: LDK120PU29R
Brand: STMicroelectronics
SKU: LDK120PU29R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LDK120PU29R

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: 6-XFDFN

Datasheet:: LDK120PU29R.pdf

Description:: IC REG LINEAR 2.9V 200MA 6DFN

Quantity:: RFQ Add To RFQ list

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Product details

Overview

LDK120PU29R from STMicroelectronics is a 200 mA, 2.9 V fixed-output low-dropout (LDO) regulator in DFN6 (1.2 × 1.3 mm) package, featuring 100 mV typical dropout at 100 mA, ±2.0% output voltage tolerance at 25 °C, and 100 µA max quiescent current - optimized for battery-powered mobile phones and digital still cameras requiring ultra-low noise and logic-controlled shutdown.

For engineers reviewing the LDK120PU29R datasheet, LDK120PU29R pinout, LDK120PU29R application, or LDK120PU29R equivalent, this page delivers verified electrical specs, thermal performance data, EN-controlled shutdown behavior, ceramic-capacitor stability (1 µF COUT), and real-world load/line transient response - all critical for low-power portable system power rail design.

Technical Context

The LDK120PU29R implements a PMOS pass transistor architecture enabling very low dropout (100 mV typ. @ 100 mA) across its 1.9–5.5 V input range. Its internal bandgap reference and error amplifier deliver tight DC regulation (±2.0% @ 25 °C) and low static line/load regulation (0.05 %/V and 0.006 %/mA).

Noise performance is enhanced via optional 10 nF bypass capacitor on the BYP pin, reducing output noise to 51 µVRMS (10 Hz–100 kHz); without it, noise rises to 148 µVRMS. The device integrates thermal shutdown (160 °C, 20 °C hysteresis) and short-circuit current limiting (400 mA typ.), with enable logic (VIL ≤ 0.4 V, VIH ≥ 1.2 V) supporting sub-1 µA shutdown current.

Key Specifications

Parameter	Value and Actual Design Meaning
Output voltage	Fixed 2.9 V ±2.0% at 25 °C - ensures stable biasing for 2.8–3.0 V logic rails and analog sensors.
Max output current	200 mA guaranteed - supports moderate-current peripherals like camera modules or RF front-ends.
Dropout voltage	100 mV typical at 100 mA - enables operation down to VIN = 3.0 V while maintaining 2.9 V output.
Quiescent current	≤100 µA max (active), <1 µA in OFF mode - extends battery life in standby and sleep states.
Output noise	51 µVRMS (10 Hz–100 kHz, with 10 nF BYP cap) - meets noise-sensitive analog supply requirements (e.g., ADC reference, RF LNA).
Supply rejection	55 dB (120 Hz–10 kHz) - suppresses ripple from noisy switching supplies feeding the LDO input.
Operating temperature	−40 °C to +125 °C junction - qualified for automotive cabin and industrial handheld environments.

Pinout & Package

LDK120PU29R is housed in a 6-pin DFN package (1.2 mm × 1.3 mm, 0.4 mm height), compatible with high-density PCB layouts and automated assembly. Thermal resistance is R_thJA = 237 °C/W and R_thJC = 104 °C/W.

Pin/Terminal	Circuit Role	Design Meaning
1 (IN)	Input voltage supply	Accepts 1.9–5.5 V DC; requires 1 µF ceramic input capacitor for stability and transient response.
2 (GND)	Power ground reference	Common return path for IN, OUT, EN, and BYP; must be low-impedance connection to minimize noise coupling.
3 (EN)	Enable control input	Active-high logic: ≥1.2 V enables regulation; ≤0.4 V forces shutdown (<1 µA I_Q).
4 (BYP/ADJ/NC)	Bypass capacitor terminal (fixed version)	Connects to 10 nF ceramic cap for noise reduction; left floating if unused - no routing required.
5 (OUT)	Regulated output	Delivers 2.9 V ±2.0%; stable with 1–22 µF ceramic output capacitor (ESR <10 Ω @ 100 kHz).
6 (N/C)	Not connected	Internally unconnected; must be tied to GND per layout guidelines to ensure mechanical reliability and thermal conduction.

Key Features

Feature	Design Value
Ultra-low noise with bypass option	51 µVRMS (10 Hz–100 kHz) using 10 nF BYP cap - enables clean power for precision analog circuits.
Logic-controlled shutdown	EN pin reduces total current to <1 µA - essential for zero-power sleep modes in portable devices.
Ceramic capacitor compatibility	Stable with 1 µF COUT (min) - eliminates need for costly tantalum or electrolytic capacitors.
Wide input voltage range	1.9–5.5 V operation - supports single-cell Li-ion (2.7–4.2 V), Li-polymer, or dual-cell alkaline inputs.
Integrated protection	Thermal shutdown (160 °C) and constant-current short-circuit limiting (400 mA) - prevents damage during fault conditions.

Applications

Mobile Phone Power Management

Digital Still Camera Sensor Supply

Use Scenario: Providing regulated 2.9 V supply to image sensor analog front-end and ISP core in compact smartphones.

IC Role / Device Role / Timing Role: Primary low-noise LDO delivering clean bias to CMOS image sensor and analog-to-digital converter circuitry.

Use Value: 51 µVRMS noise and 0.006 %/mA load regulation prevent image artifacts and quantization errors under dynamic current draw.

Use Scenario: Powering CCD/CMOS sensor and lens actuator driver ICs in battery-operated DSLR and mirrorless cameras.

IC Role / Device Role / Timing Role: Fixed-output LDO supplying stable 2.9 V rail with fast load transient response (<10 µs recovery) during autofocus bursts.

Use Value: 100 mV dropout enables full sensor functionality even as battery discharges below 3.0 V, extending usable runtime.

Personal Digital Assistant (PDA) Core Logic

Cordless Phone Baseband IC

Use Scenario: Delivering tightly regulated 2.9 V to ARM-based application processor and memory interface in legacy PDAs.

IC Role / Device Role / Timing Role: System-level LDO ensuring ±2.0% output accuracy across −40 °C to +85 °C operating range.

Use Value: 125 °C junction rating and 237 °C/W R_thJA allow reliable operation in sealed enclosures without forced airflow.

Use Scenario: Supplying baseband DSP and RF transceiver ICs in DECT cordless phone handsets with intermittent transmit duty cycles.

IC Role / Device Role / Timing Role: Enable-controlled LDO synchronized to RF burst timing to minimize average power consumption.

Use Value: Sub-1 µA shutdown current during receive idle periods significantly extends talk time between charges.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Torex XC6219B292MR-G	200 mA, 2.9 V fixed, SOT-25; 150 mV dropout @ 100 mA; 25 µA IQ; no EN pin.	Lacks enable control and has higher dropout - unsuitable for deep-sleep systems or low-VIN battery operation.	Select only when EN functionality and ultra-low dropout are not required; lower quiescent current benefits always-on monitoring.
Richtek RT9013-29GB	300 mA, 2.9 V fixed, SOT-25; 250 mV dropout @ 150 mA; 60 µA IQ; EN pin included.	Higher dropout and larger package footprint - limits use in space-constrained designs with tight VIN margins.	Prefer when higher output current headroom is needed; verify thermal performance with R_thJA = 250 °C/W in same layout.

Compared with XC6219B292MR-G and RT9013-29GB, LDK120PU29R uniquely combines sub-100 mV dropout, EN-controlled <1 µA shutdown, and DFN6's 1.2×1.3 mm footprint - making it optimal for next-gen compact battery-powered devices where VIN margin and sleep power are critical.

Availability

LDK120PU29R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, personal digital assistants (PDAs), and cordless phone systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LDK120PU29R 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 microcontrollers, power management ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The LDK120 series belongs to ST's ultra-low-noise, low-quiescent-current LDO portfolio - engineered specifically for battery-powered portable electronics demanding high PSRR, minimal dropout, and precise DC regulation under dynamic load conditions.

FAQ

What is the minimum input voltage required for LDK120PU29R to maintain regulation at 200 mA load?

The minimum input voltage is calculated as V_OUT + V_DROP = 2.9 V + 300 mV = 3.2 V (max dropout at 200 mA, 40–125 °C). At room temperature, 3.0 V input suffices due to 150 mV typical dropout. Below 3.0 V, output voltage sags proportionally to the deficit.

Can LDK120PU29R operate with a 1 µF ceramic output capacitor, and what ESR range is acceptable?

Yes - the device is fully stable with 1 µF X5R/X7R ceramic capacitors. Per Figure 25, stability is ensured for C_OUT = 1–22 µF and ESR ≤10 Ω at 100 kHz. Capacitors with ESR <100 mΩ (typical for 1 µF ceramics) provide optimal transient response and phase margin.

How does the BYP pin function on the fixed-output LDK120PU29R, and is it mandatory?

The BYP pin connects to a 10 nF ceramic capacitor to reduce output noise from 148 µVRMS to 51 µVRMS (10 Hz–100 kHz). It is optional: if unused, the pin must remain unconnected and un-routed - no pull-up/down or grounding is permitted per datasheet Table 1.

What thermal derating applies when operating LDK120PU29R at 200 mA in a 60 °C ambient environment?

With R_thJA = 237 °C/W, power dissipation at 200 mA and 3.2 V input is P_D = (3.2 V − 2.9 V) × 0.2 A = 60 mW. Junction rise = 60 mW × 237 °C/W = 14.2 °C → T_J = 74.2 °C, well below 125 °C limit. No derating needed at this condition.

LDK120PU29R Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 6-XFDFN

Packaging:: Tape & Reel (TR)

Product Status:: Active

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 5.5V

Voltage - Output (Min/Fixed):: 2.9V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.3V @ 200mA

Current - Output:: 200mA

Current - Quiescent (Iq):: 60 µA

Current - Supply (Max):: 100 µA

PSRR:: 55dB (120Hz ~ 10kHz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 6-DFN (1.2x1.3)

LDK120PU29R FAQ

1.How can I place an order for LDK120PU29R through Aetrix?

Please submit a Request for Quotation (RFQ) for LDK120PU29R on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LDK120PU29R reliable?

The price and inventory of LDK120PU29R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDK120PU29R is usually 5 days.

3.What payment methods are accepted for LDK120PU29R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDK120PU29R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LDK120PU29R?

LDK120PU29R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LDK120PU29R order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LDK120PU29R?

For technical support, including LDK120PU29R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDK120PU29R requirements.

6.How does Aetrix verify that LDK120PU29R is sourced from the original manufacturer or authorized distributors?

All LDK120PU29R products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LDK120PU29R meets industry standards.

7.What is the process for return or replacement of LDK120PU29R?

All LDK120PU29R units undergo pre-shipment inspection (PSI). If there is an issue with LDK120PU29R, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LDK120PU29R part is unused and in its original packaging.

Return procedure for LDK120PU29R:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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