STMicroelectronics LDK120PU32R

Overview

LDK120PU32R from STMicroelectronics is a 3.2 V fixed-output, 200 mA low-dropout linear regulator with 100 mV typical dropout at 100 mA, 100 µA max quiescent current, ±2.0% output voltage tolerance at 25 °C, and operation from 1.9 V to 5.5 V input - designed for noise-sensitive power rails in portable battery-powered systems.

For engineers reviewing the LDK120PU32R datasheet, LDK120PU32R pinout, LDK120PU32R application, or LDK120PU32R equivalent, key selection criteria include ultra-low noise (51 µVRMS with 10 nF bypass), logic-controlled shutdown (<1 µA OFF-mode current), ceramic capacitor compatibility (1 µF COUT), thermal/short-circuit protection, and DFN6 (1.2 × 1.3 mm) package suitability for space-constrained PCB layouts.

Technical Context

The LDK120PU32R employs a PMOS pass transistor architecture enabling ultra-low dropout and stable regulation down to 1.9 V input while maintaining tight output accuracy across –40 °C to 125 °C. Its internal bandgap reference and error amplifier deliver ±2.0% initial tolerance and <0.006 %/mA load regulation.

It integrates a dedicated enable input (EN) with logic-level thresholds (0.4 V low / 1.2 V high), bypass/adjust pin configured as NC in fixed versions, and robust protection including thermal shutdown (160 °C) and constant-current short-circuit limiting (400 mA). Noise performance is enhanced via optional 10 nF bypass capacitor on the BYP pin.

Key Specifications

Pinout & Package

LDK120PU32R is packaged in DFN6 (1.2 × 1.3 mm, 0.4 mm height) with wettable flanks, optimized for automated optical inspection and thermal performance (R_thJC = 104 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, low-I_Q LDO applications.

Compared with XC6210B322MR-G and RT9013-32GB, the LDK120PU32R uniquely balances ultra-low noise (51 µVRMS), robust thermal protection, and DFN6 miniaturization - making it optimal for space-constrained, noise-critical battery systems where reliability across temperature is non-negotiable.

Availability

LDK120PU32R is available at Aetrix Electronics and suitable for mobile phones, digital still cameras, wearable health monitors, and industrial handheld terminals requiring stable component supply with full production lifecycle support through July 2026.

Supply support for LDK120PU32R 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 automotive, industrial, and consumer markets.

The LDK120 series belongs to ST's ultra-low-noise, low-I_Q LDO portfolio, engineered specifically for battery-powered portable electronics demanding extended runtime, high PSRR, and minimal electromagnetic interference in compact form factors.

FAQ

What is the recommended output capacitor for LDK120PU32R?

The datasheet specifies a minimum 1 µF X5R or X7R ceramic capacitor (C_OUT) with ESR <1 Ω for stable operation. A 2.2 µF capacitor is commonly used to improve transient response. The device remains stable with values up to 22 µF, but larger capacitors require verification of ESR range per Figure 25 in DS9378 Rev 9.

Can LDK120PU32R be used with a 1.8 V input supply?

No - the absolute minimum input voltage is 1.9 V per Table 2 (Absolute Maximum Ratings). At 1.8 V, the device falls outside its operational specification and cannot regulate 3.2 V output. For 1.8 V input, consider an LDO with lower V_IN(min) or a buck-boost solution.

Is the BYP/ADJ pin required to be terminated on LDK120PU32R?

No - for the fixed-output LDK120PU32R, the BYP/ADJ pin is internally not connected (NC) and must be left floating with no PCB trace or passive component attached. Connecting it to GND or V_OUT may cause instability or parametric deviation.

Does LDK120PU32R support reverse current protection?

Yes - the PMOS pass transistor architecture provides inherent reverse current blocking. When V_OUT > V_IN, the body diode is reverse-biased and no significant reverse current flows, protecting upstream sources such as batteries or USB ports during hot-swap or fault conditions.