STMicroelectronics LD57100J100R

Overview

LD57100J100R from STMicroelectronics is a 1 A ultra-low-dropout (LDO) linear voltage regulator with NMOS pass transistor, fixed 1.00 V output, ±1% accuracy over −40 °C to +85 °C, 40 mV typical dropout at full load, and integrated output active discharge. It delivers precision post-regulation for battery-powered mobile SoC cores in smartphones and imaging modules.

For engineers reviewing the LD57100J100R datasheet, LD57100J100R pinout, LD57100J100R application, or LD57100J100R equivalent, key selection criteria include bias-supply-enabled ultra-low dropout operation, 35 µA no-load ground current, thermal shutdown at 160 °C, and Flip Chip6 package compatibility with space-constrained PCB layouts.

Technical Context

The LD57100J100R uses a dedicated VBIAS pin (3.0–5.5 V) to drive the NMOS gate independently of VIN, enabling stable regulation down to VIN = VOUT + 40 mV. Its internal reference (0.5 V ±0.5%) feeds a high-gain error amplifier controlling the pass element.

It integrates logic-controlled shutdown (EN pin), thermal foldback limiting, short-circuit current limit (1.5–2.6 A), and an on-chip 150 Ω discharge MOSFET activated during disable. Supply rejection exceeds 75 dB (VIN) and 85 dB (VBIAS) at 1 kHz, with output noise as low as 27 µVRMS (10 Hz–100 kHz).

Key Specifications

Pinout & Package

LD57100J100R is housed in a Flip Chip6 package (0.8 mm × 1.2 mm, 0.4 mm pitch), optimized for minimal footprint and thermal performance on compact mobile PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B102MR-G and RT9080L-10PU5, LD57100J100R offers the smallest footprint (0.8 × 1.2 mm), lowest dropout (40 mV), and lowest no-load IQ (35 µA), making it optimal for next-gen smartphone and wearable designs where space and battery life are critical.

Availability

LD57100J100R is available at Aetrix Electronics and suitable for smartphone application processor cores, digital camera ISPs, wearable sensor hubs, and automotive ADAS camera ECUs requiring stable component supply with consistent parametric performance across production lots.

Supply support for LD57100J100R 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 components for industrial, automotive, and consumer markets.

LD57100 belongs to ST's high-accuracy, ultra-low-dropout LDO family targeting battery-powered portable electronics - engineered specifically for post-regulation of SoC core rails where minimal voltage headroom, low noise, and rapid enable/disable response are essential.

FAQ

What is the minimum input voltage required for LD57100J100R to regulate 1.00 V at 1 A?

The minimum input voltage is VOUT + VDROP = 1.00 V + 40 mV = 1.04 V (typical). Under worst-case conditions (max dropout of 80 mV per datasheet Table 7), VIN must be ≥1.08 V. This ultra-low headroom enables direct regulation from buck converter outputs or partially discharged Li-ion cells.

Can the VBIAS pin be tied to VIN?

Yes - if VIN meets both conditions: ≥3.0 V and ≥VOUT + 1.6 V (i.e., ≥2.6 V for 1.00 V output). Since 1.04–1.08 V VIN is insufficient, VBIAS must be supplied from a separate ≥3.0 V rail (e.g., PMIC LDO or battery monitor output) in most low-input applications.

Does LD57100J100R require an external discharge resistor?

No - it integrates an active 150 Ω discharge MOSFET between VOUT and GND, activated automatically when EN is pulled low. This eliminates the need for external resistors, reduces BOM count, and ensures faster discharge (<1 ms for 10 µF COUT) than passive solutions.

How does the SNS pin function in the fixed-output LD57100J100R?

In fixed versions, the SNS pin is a Kelvin sense connection routed separately from the main VOUT trace to the load. It improves load regulation by compensating for PCB trace resistance voltage drop - critical for maintaining ±1% accuracy under dynamic current changes up to 1 A.