STMicroelectronics LDK220M33R

Overview

LDK220M33R from STMicroelectronics is a fixed-output 3.3 V, 200 mA low-dropout linear regulator in SOT23-5L 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 use in space-constrained battery-powered systems.

For engineers reviewing the LDK220M33R datasheet, LDK220M33R pinout, LDK220M33R application, or LDK220M33R equivalent, key selection criteria include dropout performance at 200 mA load, enable threshold compatibility with 1.8 V/3.3 V logic, thermal derating in SOT23-5L, and stability with ultra-low-ESR ceramic capacitors.

Technical Context

The LDK220M33R implements a bandgap-referenced error amplifier driving a PMOS pass transistor, enabling ultra-low dropout and high PSRR (55 dB @ 120 Hz–1 kHz). Its internal bias generator and thermal shutdown circuit (160 °C trip, 20 °C hysteresis) ensure safe operation under overload or ambient extremes.

Logic-controlled enable input (V_IL ≤ 0.4 V, V_IH ≥ 1.2 V) directly interfaces with standard CMOS I/O, while integrated output discharge (R_dis = 18 Ω) actively pulls VOUT to GND during shutdown - a critical feature for sequencing-sensitive power domains.

Key Specifications

Pinout & Package

LDK220M33R is supplied in SOT23-5L package (2.95 mm × 1.60 mm × 1.45 mm), optimized for high thermal resistance (R_thJA = 160 °C/W) in compact PCB layouts. Pin assignment matches JEDEC MO-178AB standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B332MR-G and AP2204K-3.3TRG1, LDK220M33R delivers superior dropout performance (100 mV), integrated thermal shutdown, and active output discharge - making it uniquely suited for battery-constrained, safety-aware, and sequencing-sensitive designs.

Availability

LDK220M33R is available at Aetrix Electronics and suitable for battery-powered equipment, set-top box subsystems, and industrial PLC I/O modules requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for LDK220M33R 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 analog LDO portfolio, engineered specifically for ultra-low-power, low-noise, and thermally demanding applications in portable and industrial electronics.

FAQ

What is the minimum input voltage required for regulation at full 200 mA load?

The LDK220M33R maintains regulation down to VIN = VOUT + VDROP. At 200 mA and TJ = 125 °C, maximum dropout is 350 mV per datasheet Table 6, so minimum input is 3.3 V + 0.35 V = 3.65 V. Below this, output voltage drops linearly with input.

Can the LDK220M33R be used with a 0.47 µF output capacitor?

No - the datasheet specifies 1 µF minimum COUT for stability (Section 6, Figure 22). Using 0.47 µF risks oscillation or poor transient response due to insufficient phase margin; 1 µF X5R ceramic is the validated minimum.

Is the EN pin 5 V tolerant when VIN = 13.2 V?

Yes - absolute maximum rating for VEN is VI + 0.3 V (Table 4), so at VIN = 13.2 V, EN accepts up to 13.5 V. However, logic compatibility is defined only for 0.4 V (low) and ≥1.2 V (high) thresholds across -40 °C to 125 °C.

Does the LDK220M33R require an input capacitor, and if so, what value?

Yes - a 1 µF ceramic capacitor (CIN) is mandatory between IN and GND, placed within 2 mm of the package, to suppress high-frequency noise and ensure loop stability. Larger values (e.g., 10 µF) may improve line transient response but are not required.