STMicroelectronics LDK715PU33R

Overview

LDK715PU33R from STMicroelectronics is a high-input-voltage, ultra-low-quiescent-current LDO linear regulator delivering 3.3 V at up to 85 mA output current, with 4.3–24 V input range, 500 mV typical dropout at full load, and −40 °C to 125 °C operating temperature-designed for battery-powered industrial sensors and mobile power rails.

For engineers reviewing the LDK715PU33R datasheet, LDK715PU33R pinout, LDK715PU33R application, or LDK715PU33R equivalent, this page provides verified package mapping (DFN8 3×3), confirmed thermal performance (R_thJA = 52 °C/W), real-world capacitor compatibility (0.47–10 µF ceramic), and validated fault protection (internal current limit, short-circuit safe).

Technical Context

The LDK715PU33R implements a bandgap reference-based control loop with internal current limiting and thermal shutdown, enabling stable regulation across wide input voltage swings without external compensation. Its low-dropout architecture maintains regulation down to 500 mV headroom at 85 mA, while the 5 µA quiescent current supports multi-year battery life in always-on monitoring nodes.

It operates with minimal external components: only input bypass (≥0.1 µF) and output stabilization (0.47–10 µF ceramic) capacitors are required. The DFN8 3×3 package's exposed thermal pad improves power dissipation capability (2 W max at T_A = 25 °C), supporting sustained 85 mA loads in compact industrial enclosures.

Key Specifications

Pinout & Package

LDK715PU33R is packaged in a thermally enhanced DFN8 3×3 mm, 0.4 mm pitch, with an exposed thermal pad (Exp. pad) that must be left floating or connected to GND for optimal thermal performance and EMI reduction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B332MR-G and ADM7172ACPZ-3.3-R7, the LDK715PU33R uniquely balances 24 V input tolerance, 5 µA quiescent current, and DFN8 thermal performance-making it the optimal choice for space-constrained, battery- or bus-powered industrial regulators where input voltage variability and long service life are critical.

Availability

LDK715PU33R is available at Aetrix Electronics and suitable for industrial sensor nodes, portable medical monitors, smart meter auxiliary rails, and automotive body control modules requiring stable component supply across extended temperature and input voltage ranges.

Supply support for LDK715PU33R 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 devices for industrial, automotive, and consumer markets.

The LDK715 series belongs to ST's high-voltage, ultra-low-I_Q LDO portfolio-engineered specifically for battery longevity and robustness in harsh industrial and mobile environments where input voltage fluctuation and thermal constraints dominate design decisions.

FAQ

What is the maximum allowable input voltage for LDK715PU33R?

The absolute maximum DC input voltage is 26 V, but the recommended operating range is 4.3 V to 24 V per datasheet specifications. Operation above 24 V risks exceeding thermal limits even at light loads due to increased power dissipation (P_D = (V_IN − 3.3 V) × I_OUT), especially in the DFN8 package at elevated ambient temperatures.

Can LDK715PU33R be used with a 0.47 µF ceramic output capacitor?

Yes-the datasheet explicitly guarantees stability with ceramic output capacitors ranging from 0.47 µF to 10 µF, provided ESR remains below 100 mΩ. A 0.47 µF X7R 0603 capacitor meets this requirement and is commonly used to minimize board area in space-constrained designs like wearables and sensor tags.

Does LDK715PU33R include enable or shutdown functionality?

No-the LDK715PU33R has no enable pin or shutdown mode. It operates continuously whenever valid input voltage is applied. For applications requiring controlled power sequencing, an external MOSFET switch or a variant like LDK715PU33R-TR (if offered with EN) must be used-this specific part number is always-on.

How does thermal performance differ between SOT23-5L and DFN8 packages?

The DFN8 3×3 package has R_thJA = 52 °C/W versus 195 °C/W for SOT23-5L, enabling ~3.7× higher power dissipation at the same ambient temperature. With 85 mA load and 24 V input, the DFN8 dissipates ~1.76 W and stays within safe junction limits (T_J ≈ 115 °C at 25 °C ambient), whereas the SOT23-5L would exceed 125 °C junction limit under identical conditions.