STMicroelectronics LD57100J120R

Overview

LD57100J120R from STMicroelectronics is a 1.20 V fixed-output, ultra-low-dropout (LDO) linear voltage regulator with NMOS pass transistor architecture, 40 mV typical dropout at 1 A load, ±1% output voltage tolerance over −40 °C to +85 °C, and logic-controlled shutdown enabling <0.1 µA standby current. It delivers up to 1 A for low-noise post-regulation in space-constrained mobile power rails.

For engineers reviewing the LD57100J120R datasheet, LD57100J120R pinout, LD57100J120R application, or LD57100J120R equivalent, key selection criteria include bias-supply-dependent ultra-low dropout performance, active output discharge, thermal/short-circuit protection, and Flip Chip6 package integration into high-density smartphone and camera PMIC subsystems.

Technical Context

The LD57100J120R uses an NMOS pass element driven by a dedicated VBIAS pin (3.0–5.5 V), decoupling gate drive from VIN to sustain ultra-low dropout even when VIN approaches VOUT. Its internal reference (0.5 V typ.) and error amplifier enable ±1% output accuracy across temperature and load.

It integrates independent protection blocks: thermal shutdown at 160 °C with 20 °C hysteresis, current limiting (1.5–2.6 A), and an output-discharge MOSFET (RON = 150 Ω typ.) activated upon EN deassertion. Supply rejection exceeds 75 dB (VIN) and 85 dB (VBIAS) at 1 kHz.

Key Specifications

Pinout & Package

LD57100J120R is housed in a Flip Chip6 package (0.8 mm × 1.2 mm, 0.315 mm height), optimized for minimal PCB footprint and thermal resistance (R_thJA = 60 °C/W on standard 4-layer JEDEC board).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-dropout LDO applications.

Compared with XC6210B122MR-G and RT9080AL-12PU5, LD57100J120R uniquely combines sub-50 mV dropout, bias-supply isolation for superior PSRR, and integrated output discharge - making it optimal for high-density, multi-rail mobile designs requiring precise sequencing and noise immunity.

Availability

LD57100J120R is available at Aetrix Electronics and suitable for smartphone power management, camera module regulation, wearable sensor hubs, and low-power IoT MCU rails requiring stable component supply with guaranteed 1 A output and −40 °C to +85 °C operation.

Supply support for LD57100J120R 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 specializing in power management, microcontrollers, and analog ICs for automotive, industrial, and consumer markets.

The LD57100 series targets ultra-compact, high-efficiency post-regulation in battery-powered portable electronics - engineered to replace discrete bias solutions with integrated VBIAS-driven NMOS LDOs that maximize battery runtime and signal integrity.

FAQ

What is the minimum required VBIAS voltage for LD57100J120R?

The minimum VBIAS voltage is the greater of 3.0 V or VOUT + 1.6 V - for LD57100J120R (1.20 V output), this is 2.80 V, so the absolute minimum is 3.0 V. Operating below this disables internal gate drive, causing regulation failure or thermal shutdown. VBIAS must remain within 3.0–5.5 V per datasheet Table 6.

Can LD57100J120R operate without an external VBIAS supply?

No - VBIAS is mandatory. The NMOS pass transistor requires dedicated biasing independent of VIN. If VIN satisfies both VOUT + VDROP and the VBIAS requirement (≥3.0 V and ≥VOUT + 1.6 V), VBIAS may be tied to VIN; otherwise, a separate low-noise 3.3 V or 5 V rail is required. Omitting VBIAS causes immediate functional failure.

How does the SNS pin improve regulation accuracy in LD57100J120R?

The SNS pin provides remote sensing of VOUT at the load, compensating for voltage drop across PCB traces between the LDO and load. In fixed versions, connecting SNS directly to the load's VDD pin (via dedicated trace) ensures the error amplifier regulates based on actual load voltage - maintaining ±1% accuracy even with 100 mΩ trace resistance at 1 A.

Is LD57100J120R compatible with ceramic output capacitors smaller than 10 µF?

Yes - the control loop is stable with ≥1.0 µF X5R/X7R ceramic capacitors (ESR 3–300 mΩ). The 10 µF value in typical circuits is recommended for optimal transient response under 1 A load steps, but 2.2 µF suffices for static loads. Capacitor placement within 2 mm of VOUT/GND pins is critical to maintain stability.