STMicroelectronics ST715C50R

Overview

ST715C50R from STMicroelectronics is a fixed-output 5.0 V, high-input-voltage (2.5–24 V), ultra-low-quiescent-current (3.8 µA typ. at full load) LDO linear regulator delivering up to 85 mA output current with 500 mV typical dropout voltage at full load. It operates across –40 °C to +125 °C and supports ceramic output capacitors as low as 0.47 µF - deployed in battery-powered portable electronics requiring long runtime and wide supply tolerance.

For engineers reviewing the ST715C50R datasheet, ST715C50R pinout, ST715C50R application, or ST715C50R equivalent, key selection criteria include input voltage range compatibility, quiescent current under load, thermal performance in SOT23-5L/SOT323-5L/DFN8 packages, and stability with low-ESR ceramic capacitors in space-constrained designs.

Technical Context

The ST715C50R implements a bandgap reference-based error amplifier with internal current limiting and thermal shutdown. Its feedback loop is internally configured for fixed 5.0 V output, eliminating external resistors - unlike the adjustable ST715 variants that require FB-pin resistor dividers.

It features a dedicated bias generator and low-noise architecture enabling 210 µV_RMS output noise (200 Hz–100 kHz) and 38 dB PSRR at 1 kHz, optimized for powering sensitive analog or RF subsystems in mixed-signal portable devices.

Key Specifications

Pinout & Package

ST715C50R is available in SOT23-5L, SOT323-5L, and DFN8 (3×3 mm) packages. Pin functions are identical across all variants per Table 3 (SOT23-5L/SOT323-5L) and Table 2 (DFN8) of DS5704 Rev 16.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B502MR-G and AP7361-C5-33, ST715C50R uniquely balances 24 V input tolerance, 5.0 V precision, and sub-6 µA quiescent current - making it irreplaceable in wide-input, battery-sensitive 5 V applications where voltage accuracy and longevity are co-prioritized.

Availability

ST715C50R is available at Aetrix Electronics and suitable for wearable health monitors, industrial sensor nodes, smart home hubs, and portable diagnostic tools requiring stable component supply across extended temperature and voltage ranges.

Supply support for ST715C50R 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 ST715 series was developed specifically for ultra-low-power, high-input-voltage LDO regulation in space- and energy-constrained portable and industrial electronics - emphasizing long battery life, wide supply flexibility, and robust thermal behavior.

FAQ

What is the minimum input voltage required for ST715C50R to regulate 5.0 V output?

The ST715C50R requires a minimum input voltage of 5.5 V to maintain regulation at full 85 mA load, based on its 500 mV typical dropout voltage. At lighter loads, regulation begins as low as 2.5 V input, but output will drop below 5.0 V if VIN falls below V_OUT + V_DROP - verified in Table 7 electrical characteristics under I_OUT = 85 mA conditions.

Can ST715C50R be used with a 10 µF ceramic output capacitor?

Yes - the ST715C50R is explicitly characterized and stable with ceramic output capacitors ranging from 0.47 µF to 10 µF, as confirmed in the "Features" section and Table 7 notes. No series resistance or special dielectric type is required; standard X5R or X7R 10 µF ceramics are fully supported.

Does ST715C50R include enable or shutdown functionality?

No - the ST715C50R has no enable (EN) pin or shutdown mode. It operates continuously when input voltage is applied within specification. For controlled power sequencing, an external MOSFET switch on the IN rail or a separate enable-capable LDO (e.g., ST715MR) must be used.

How does thermal performance differ between SOT23-5L and DFN8 packages?

The DFN8 (3×3 mm) package has a junction-to-ambient thermal resistance (R_thJA) of 52 °C/W versus 195 °C/W for SOT23-5L - enabling ~3.7× higher continuous power dissipation at the same ambient temperature. This allows the DFN8 variant to sustain 85 mA at higher input voltages (e.g., 12 V → 5 V) without thermal derating, while SOT23-5L requires careful layout or reduced load.