STMicroelectronics LD57100J800R

Overview

LD57100J800R from STMicroelectronics is a fixed-output 0.8 V, 1 A ultra-low-dropout linear regulator (LDO) with NMOS pass transistor and dedicated VBIAS pin for sub-1 V operation. It delivers ±1% output accuracy over −40 °C to +85 °C, 40 mV dropout at 1 A load, and 35 μA ground current at no load-enabling high-efficiency post-regulation in space-constrained battery-powered systems such as smartphone core logic rails.

For engineers reviewing the LD57100J800R datasheet, LD57100J800R pinout, LD57100J800R application, or LD57100J800R equivalent, key selection criteria include bias-supply flexibility (3.0–5.5 V), active output discharge, thermal shutdown (160 °C), and Flip Chip6 package compatibility with low-noise ceramic output capacitors (≥1 µF, X5R/X7R).

Technical Context

The LD57100J800R employs an NMOS pass element driven by a separate VBIAS supply, decoupling control circuitry from VIN to sustain ultra-low dropout even when VIN approaches VOUT (e.g., 0.8 V). Its internal reference (0.5 V) and feedback network are optimized for fixed 0.8 V output with ±0.5% tolerance at 25 °C and ±1% across full temperature range.

It integrates logic-controlled enable (EN), thermal shutdown with 20 °C hysteresis, current limiting (1.5–2.6 A), and an internal discharge MOSFET (RON = 150 Ω) activated during shutdown. Supply rejection exceeds 75 dB (VIN) and 85 dB (VBIAS) at 1 kHz, while output noise is 27 µVRMS (10 Hz–100 kHz) for fixed versions.

Key Specifications

Pinout & Package

LD57100J800R is housed in a Flip Chip6 package (0.8 mm × 1.2 mm, 0.4 mm pitch), optimized for minimal PCB footprint and thermal performance (R_thJA = 60 °C/W on standard 4-layer JEDEC board). The die-down construction enables direct thermal coupling to inner copper planes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B082MR-G and RT9080L-08GJ5, LD57100J800R uniquely combines sub-50 mV dropout, VBIAS-enabled ultra-low-input operation, active discharge, and the smallest available footprint-making it optimal for next-gen mobile SoC power delivery where input headroom, board area, and rail sequencing are tightly constrained.

Availability

LD57100J800R is available at Aetrix Electronics and suitable for smartphone core rails, camera sensor power, wearable SoC I/O, and LPDDR memory interfaces requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for LD57100J800R 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 microcontrollers, power management ICs, sensors, and analog devices for automotive, industrial, and consumer markets.

LD57100J800R belongs to ST's high-accuracy, ultra-low-dropout LDO family engineered specifically for advanced mobile and portable electronics demanding minimal voltage headroom, nanoscale footprints, and robust protection features.

FAQ

Can LD57100J800R operate with VIN equal to VOUT?

No. Minimum VIN is VOUT + VDROP, which is 0.84 V (0.8 V + 40 mV typ.) at 1 A load. Below this, regulation fails and output collapses. The VBIAS pin must also be ≥3.0 V or ≥VOUT + 1.6 V (≥2.4 V), so practical minimum VIN is governed by whichever requirement is larger - typically VBIAS constraint dominates at very low VOUT.

What is the purpose of the separate SNS pin?

The SNS (sense) pin provides Kelvin feedback for the fixed-output version, allowing the regulator to monitor voltage directly at the load rather than at the VOUT pin. This compensates for IR drop across PCB traces, ensuring ±1% accuracy at the point-of-load - essential for precision core rails where even 10 mV error impacts timing margins.

Is an external capacitor required on the VBIAS pin?

Yes. A minimum 100 nF ceramic capacitor (X5R/X7R) must be placed between VBIAS and GND, located as close as possible to the pin. This stabilizes the bias supply for the internal gate driver and prevents oscillation or erratic enable behavior under dynamic load conditions.

Does LD57100J800R support reverse current blocking?

No. The NMOS pass transistor architecture does not provide inherent reverse current blocking. If reverse current flow from VOUT to VIN is possible in the system (e.g., during hot-swap or partial power-down), an external Schottky diode or ideal diode controller must be added in series with VIN.