STMicroelectronics ST732M30R

Overview

ST732M30R from STMicroelectronics is a 300 mA, fixed 3.0 V 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 and supports low-ESR ceramic capacitors as small as 0.47 µF.

For engineers reviewing the ST732M30R datasheet, ST732M30R pinout, ST732M30R application, or ST732M30R equivalent, key selection criteria include dropout voltage at 300 mA (≤1.2 V), thermal shutdown threshold (160 °C), current limit behavior vs. (VIN–VOUT), PSRR at 1 kHz (75 dB), and compatibility with permanent-battery-connected smoke detectors and electronic meters.

Technical Context

The ST732M30R integrates a bandgap reference, error amplifier, and current-limit/thermal-protection circuitry in a single-stage LDO architecture. Its SOA-based current limit dynamically scales with (VIN–VOUT) to constrain power dissipation, while thermal shutdown activates at ~160 °C with 20 °C hysteresis.

Stability is ensured with ≥0.47 µF X5R/X7R ceramic output capacitors (ESR 5–500 mΩ); no external compensation is required. The device operates without load and maintains regulation under fast load transients up to 300 mA, supported by 70 µV_RMS output noise (10 Hz–100 kHz).

Key Specifications

Pinout & Package

SOT23-5L package: 5-pin surface-mount, 1.45 mm height, 2.95 mm × 1.60 mm footprint, thermal pad not present. Designed for high-density PCB layouts with minimal board area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B302MR-G and AP2204K-3.0TRG1, the ST732M30R uniquely balances ultra-low IQ (5 µA), 28 V input capability, and integrated thermal/current protection - making it the only choice for battery-backed industrial meters and safety-critical smoke alarms requiring both longevity and fault resilience.

Availability

ST732M30R is available at Aetrix Electronics and suitable for electronic meters, smoke detectors, and portable medical devices requiring stable component supply, long-term lifecycle support, and guaranteed parametric compliance across automotive-grade temperature ranges.

Supply support for ST732M30R 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, specializing in power management, microcontrollers, and analog/mixed-signal ICs for industrial, automotive, and consumer markets.

The ST732 series targets ultra-low-power, wide-input LDO applications in battery-permanent and harsh-environment systems - emphasizing longevity, reliability, and integrated protection over cost-minimized alternatives.

FAQ

What is the minimum output capacitance required for ST732M30R stability?

The ST732M30R requires a minimum 0.47 µF ceramic capacitor (X5R/X7R dielectric) on the VOUT pin with ESR between 5 mΩ and 500 mΩ across -40 °C to +125 °C. Capacitance must remain stable over temperature and voltage; larger values improve transient response but are not mandatory.

Does ST732M30R support adjustable output voltages?

No. ST732M30R is a fixed-output device delivering precisely 3.0 V. STMicroelectronics offers no adjustable variant in the ST732 family; alternative families like STLQ015 or LD3985 provide adjustable outputs but differ in IQ, current rating, and protection features.

Can ST732M30R be used with input voltages below 2.5 V?

No. Absolute minimum input voltage is 2.5 V per datasheet Table 2. Operation below this risks loss of regulation and potential damage. At VIN = 2.5 V and VOUT = 3.0 V, the device cannot maintain regulation due to insufficient headroom - dropout voltage is specified starting at VIN = VOUT + 0.1 V.

Is thermal shutdown reversible without power cycling?

Yes. Thermal shutdown is fully automatic and self-recovering: when junction temperature falls below ~140 °C (20 °C hysteresis), the device resumes normal regulation without external intervention. No reset pin or power cycle is needed, enabling robust operation in thermally constrained enclosures.