STMicroelectronics ST732M50R

Overview

ST732M50R from STMicroelectronics is a 300 mA, 5.0 V fixed-output low-dropout (LDO) voltage regulator in SOT23-5L package, designed for post-regulation and battery-powered systems requiring ultra-low quiescent current (5 µA typ.), ±2% output accuracy, and operation across -40 °C to +125 °C. It delivers stable regulation from 2.5 V to 28 V input with dropout as low as 200 mV at 100 mA.

For engineers reviewing the ST732M50R datasheet, ST732M50R pinout, ST732M50R application, or ST732M50R equivalent, key selection criteria include its 5 µA no-load IQ, thermal shutdown (160 °C), current limit protection, stability with 0.47 µF ceramic output capacitors, and suitability for smoke detectors, electronic meters, and industrial sensors where standby power efficiency is critical.

Technical Context

The ST732M50R implements a bandgap-referenced error amplifier with internal bias generator and overtemperature/overcurrent protection logic. Its SOA-based current limit varies with (VIN–VOUT) to constrain power dissipation under overload, and thermal shutdown includes 20 °C hysteresis for reliable recovery.

It operates with low-ESR ceramic capacitors (≥0.47 µF, 5–500 mΩ ESR) and achieves 75 dB PSRR at 120 Hz and 1 kHz (VOUT = 5 V), while maintaining <0.05 %/V line regulation and <0.0001 %/mA load regulation across full temperature range.

Key Specifications

Pinout & Package

SOT23-5L package: 5-pin surface-mount, 1.45 mm height, 2.95 mm × 1.60 mm footprint, with exposed pad not electrically connected. Designed for high-density PCB layouts and compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6206P502MR and MIC5205-5.0YM5, the ST732M50R uniquely combines 300 mA output, 28 V input, and 5 µA IQ in SOT23-5L - enabling single-LDO solutions in high-voltage, ultra-low-power applications where alternatives require derating or supplemental regulation.

Availability

ST732M50R is available at Aetrix Electronics and suitable for smart utility meters, smoke detectors, and industrial sensor nodes requiring stable component supply, long-lifecycle support, and guaranteed parametric compliance across automotive-grade temperature ranges.

Supply support for ST732M50R 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, delivering silicon solutions for automotive, industrial, and power management applications since 1987.

The ST732 series belongs to ST's precision low-power LDO portfolio, engineered specifically for battery-critical and wide-input industrial systems where quiescent current, thermal resilience, and input voltage flexibility define system viability.

FAQ

What is the minimum output capacitance required for ST732M50R stability?

The ST732M50R requires a minimum 0.47 µF ceramic output capacitor with ESR between 5 mΩ and 500 mΩ for guaranteed loop stability. X5R or X7R dielectrics are recommended. Larger values improve transient response but must maintain ESR within spec across temperature and bias voltage.

Does ST732M50R support adjustable output voltage configurations?

No. The ST732M50R is a fixed 5.0 V output device. ST offers other members of the ST732 family (e.g., ST732M12R) with different fixed voltages, but no adjustable variant exists in this series. External feedback resistors cannot be added - pins 4 and 5 are NC and not internally connected.

Can ST732M50R operate safely at 28 V input continuously?

Yes - 28 V is the rated maximum continuous input voltage per datasheet Table 2. However, power dissipation (PD = (VIN − 5 V) × IOUT) must be managed: at 28 V and 300 mA, PD = 6.9 W, exceeding the SOT23-5L's thermal limits. Derating or PCB copper area enhancement is mandatory for high-VIN/high-IOUT operation.

Is there a recommended input capacitor value beyond the minimum 0.1 µF?

Yes. While 0.1 µF is the minimum, ST recommends ≥1 µF ceramic input capacitance for applications with fast load transients or high source impedance. A parallel combination (e.g., 0.1 µF + 1 µF) improves high-frequency decoupling and reduces input ripple propagation into the LDO control loop.