STMicroelectronics LDK220PU50R

Overview

LDK220PU50R from STMicroelectronics is a 5.0 V fixed-output, 200 mA low-dropout linear regulator in DFN6-1.2×1.3 package, featuring 100 mV typical dropout at 100 mA, ±2.0% output voltage tolerance at 25 °C, and logic-controlled shutdown with <1 µA off-mode current. It supports ceramic output capacitors as low as 1 µF and operates across -40 °C to 125 °C for battery-powered and industrial power rail applications.

For engineers reviewing the LDK220PU50R datasheet, LDK220PU50R pinout, LDK220PU50R application, or LDK220PU50R equivalent, key selection criteria include dropout voltage under load, quiescent current vs. temperature, EN pin logic thresholds, thermal shutdown hysteresis, and compatibility with 1 µF ceramic COUT in space-constrained designs.

Technical Context

The LDK220PU50R implements a bandgap-referenced error amplifier driving a PMOS pass transistor, enabling ultra-low dropout and stable regulation with minimal external components. Its internal bias generator ensures consistent operation across the full input range (2.5 V to 13.2 V) and junction temperature (-40 °C to 125 °C).

Logic-controlled enable functionality interfaces directly with microcontroller GPIOs, while integrated output discharge (R_dis = 18 Ω) actively pulls VOUT to GND during shutdown - a critical feature for sequencing-sensitive systems. Thermal protection triggers at 160 °C with 20 °C hysteresis to prevent latch-up.

Key Specifications

Pinout & Package

LDK220PU50R is packaged in a 6-pin DFN (1.2 mm × 1.3 mm, 0.4 mm height) with wettable flanks, optimized for automated optical inspection and thermal performance (R_thJC = 104 °C/W). The package is ECOPACK® compliant and RoHS-certified.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6206P502MR and AP2204K-5.0TRG1, LDK220PU50R uniquely combines sub-100 mV dropout, <1 µA shutdown, and integrated output discharge in a 1.2×1.3 mm DFN - enabling compact, low-power, and sequenced power architectures unattainable with alternatives.

Availability

LDK220PU50R is available at Aetrix Electronics and suitable for portable medical sensors, industrial HMI panels, set-top box USB peripherals, and automotive infotainment accessories requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LDK220PU50R 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 LDK220 series belongs to ST's precision low-quiescent-current LDO portfolio, engineered specifically for battery-powered and thermally constrained applications demanding ultra-low noise, fast transient response, and robust enable-controlled sequencing.

FAQ

What is the minimum input voltage required for LDK220PU50R to maintain 5.0 V output at 200 mA?

The minimum input voltage is determined by dropout: at 200 mA, max dropout is 350 mV (per Table 6), so VIN must be ≥ 5.35 V to sustain 5.0 V output. At 100 mA, 100 mV typical dropout allows VIN ≥ 5.1 V. Input below 2.5 V is prohibited per absolute maximum ratings.

Can LDK220PU50R be used with a 10 µF ceramic output capacitor instead of the recommended 1 µF?

Yes - the stability region in Figure 22 confirms stable operation up to 22 µF C_OUT. A 10 µF X7R ceramic improves load transient response and reduces output ripple, especially under dynamic loads like microcontroller wake-up bursts, without compromising phase margin.

Is the ADJ pin on LDK220PU50R functional, and what happens if it is accidentally connected?

No - LDK220PU50R is a fixed-output variant; Pin 3 (ADJ/NC) is internally disconnected. Connecting it externally has no effect on regulation, but ST recommends leaving it floating or tying to GND per layout best practices to avoid parasitic coupling.

How does the output discharge function behave when EN is pulled low, and what design precautions apply?

When EN goes low, an internal 18 Ω resistor actively discharges VOUT to GND. To prevent damage, ST explicitly warns against applying external voltage to VOUT while EN is low - doing so forces reverse current through the discharge path, risking reliability degradation per DS10219 Section 2 note.