STMicroelectronics LD59015C18R

Overview

LD59015C18R from STMicroelectronics is a 150 mA low-noise linear voltage regulator with fixed 1.8 V output, 2.4–5.5 V input range, 150 mV typical dropout at 150 mA, ±1.8% output accuracy at 25 °C, and 20 µV_RMS output noise - designed for power-sensitive RF and analog circuitry in portable battery-powered systems.

For engineers reviewing the LD59015C18R datasheet, LD59015C18R pinout, LD59015C18R application, or LD59015C18R equivalent, key selection criteria include PSRR performance (80 dB @ 100 Hz), ultra-low quiescent current (31 µA typ. at no load), logic-controlled shutdown (<1 µA OFF mode), ceramic capacitor compatibility, and SOT323-5L thermal robustness across –40 °C to 125 °C.

Technical Context

The LD59015C18R implements a bandgap-referenced LDO architecture with internal trimming for 1.8 V output, integrated thermal shutdown (160 °C trigger, 20 °C hysteresis), and current-limit protection (200 mA short-circuit). Its enable input (EN) accepts TTL-compatible logic thresholds (V_EN(H) ≥ 0.9 V, V_EN(L) ≤ 0.4 V) for precise system-level power sequencing.

PSRR is frequency-dependent: 80 dB at 100 Hz, 76 dB at 10 kHz, and 54 dB at 100 kHz - indicating strong low-frequency ripple rejection critical for ADC reference supplies and RF bias rails. Dropout behavior is specified only for V_OUT ≥ 1.7 V, confirming suitability for 1.8 V operation.

Key Specifications

Pinout & Package

LD59015C18R is housed in a compact, thermally enhanced SOT323-5L package (1.8 × 2.1 mm, 0.9 mm height) with exposed pad for improved heat dissipation - suitable for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B182MR-G and ADP160ACBZ-1.8-R7, LD59015C18R delivers superior PSRR (80 dB vs. ≤70 dB), integrated thermal protection, and tighter output tolerance (±1.8% vs. ±2%), making it optimal for thermally demanding, noise-sensitive battery-powered instrumentation.

Availability

LD59015C18R is available at Aetrix Electronics and suitable for wearable electronics, BLE modules, and portable medical devices requiring stable component supply, long-term lifecycle assurance, and automotive-grade reliability under extended temperature operation.

Supply support for LD59015C18R 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 innovative silicon solutions for automotive, industrial, and consumer markets since 1987.

LD59015 belongs to ST's high-performance LDO portfolio targeting ultra-low-noise, low-quiescent-current power management in battery-constrained applications - emphasizing precision, efficiency, and robustness in portable and edge-sensing systems.

FAQ

What is the minimum input voltage required for stable 1.8 V output at full 150 mA load?

The LD59015C18R requires VIN ≥ VOUT + VDROP = 1.8 V + 210 mV (max. dropout) = 2.01 V. However, the absolute minimum specified operating input is 2.4 V per datasheet Table 5 - ensuring guaranteed 150 mA output across temperature and process variation. Below 2.4 V, regulation may degrade or current limit activate.

Can LD59015C18R operate with a 0.47 µF output capacitor?

No - the datasheet specifies COUT = 1–4.7 µF ceramic with ESR ≤ 1 Ω at 100 kHz for stability. A 0.47 µF capacitor falls below the minimum value and risks oscillation or poor transient response, especially under load steps. Use at least 1 µF X5R/X7R in 0603 or larger case size.

Is the NC pin (Pin 4) required to be left floating or can it be grounded?

Pin 4 is internally unconnected and must be left floating per ST's layout guidelines. Grounding or routing this pin may introduce parasitic coupling or violate internal isolation; ST does not characterize or guarantee performance if Pin 4 is tied to any potential. Follow Figure 2 (top view) and Table 2 strictly.

Does LD59015C18R include undervoltage lockout (UVLO)?

Yes - it features dual-threshold UVLO: turn-on occurs at VIN ≥ 2.15 V (typ.), and turn-off at VIN ≤ 1.95 V (typ.). This hysteresis prevents oscillation near the input threshold and protects downstream circuits during brown-out conditions, as verified in Figure 10 and Table 3 of the datasheet.