NXP Semiconductors LD6816CX4/36P,315

Overview

LD6816CX4/36P,315 from NXP Semiconductors is a 3.6 V fixed-output, 150 mA ultra-low-dropout linear regulator in WLCSP4 package with auto-discharge (pull-down) functionality. It delivers 45 mV dropout at full load, 30 µV_RMS output noise (10 Hz–100 kHz), and 55 dB PSRR at 1 kHz-designed for powering noise-sensitive analog/digital cores in space-constrained portable devices.

For engineers reviewing the LD6816CX4/36P,315 datasheet, LD6816CX4/36P,315 pinout, LD6816CX4/36P,315 application, or LD6816CX4/36P,315 equivalent, key selection criteria include its 3.6 V output accuracy (±2% over −30°C to +85°C), sub-150 µs startup time, 0.1 µA shutdown quiescent current, and integrated thermal/overcurrent protection-critical for battery-powered mobile interface rails.

Technical Context

The LD6816CX4/36P,315 employs a PMOS pass transistor architecture enabling ultra-low dropout and high PSRR across 1 kHz–100 kHz. Its enable input (active HIGH) controls both regulation and the integrated pull-down switch, ensuring rapid output discharge during disable-eliminating floating voltage on downstream circuitry.

Designed for stability with 1.0 µF X7R ceramic output capacitance (ESR 5–500 mΩ), it operates across 2.3 V–5.5 V input while maintaining ±0.5% output tolerance at 25°C and ±3% over temperature. The device integrates ESD protection (10 kV HBM) and thermal shutdown (160°C with 20 K hysteresis).

Key Specifications

Pinout & Package

Package: Wafer-Level Chip-Scale Package (WLCSP4), 0.76 mm × 0.76 mm × 0.47 mm, 0.4 mm pitch, 4 solder bumps (2×2), Pb-free/RoHS/halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B362MR-G and RT9013-36GB, the LD6816CX4/36P,315 uniquely combines ultra-low dropout (45 mV), low noise (30 µV_RMS), and integrated auto-discharge in a 0.76 mm × 0.76 mm WLCSP-enabling superior power efficiency, EMI resilience, and system-level simplification in miniaturized portable designs.

Availability

LD6816CX4/36P,315 is available at Aetrix Electronics and suitable for smartphone application processor core rails, digital still camera image sensor bias, and portable media player audio codec supplies requiring stable component supply with guaranteed long-term availability.

Supply support for LD6816CX4/36P,315 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

NXP Semiconductors is a global semiconductor company specializing in secure connectivity solutions for automotive, industrial, and consumer applications, with leadership in power management and RF technologies.

The LD6816 series was designed specifically for ultra-miniaturized, low-noise power delivery in portable electronics-targeting applications where board space, battery life, and signal integrity are primary constraints.

FAQ

What is the nominal output voltage and tolerance of the LD6816CX4/36P,315?

The LD6816CX4/36P,315 provides a fixed 3.6 V output with ±0.5% tolerance at +25°C and ±2% over the full operating temperature range of −30°C to +85°C. This accuracy is specified under 1 mA load and ensures reliable operation of 3.3 V–3.6 V logic interfaces without external trimming. The LD6816CX4/36P,315 achieves this via laser-trimmed internal resistor network and monolithic silicon process control.

Does the LD6816CX4/36P,315 include an auto-discharge feature, and how does it operate?

Yes, the LD6816CX4/36P,315 integrates an active pull-down transistor that places the OUT pin in a low-ohmic state (typical 100 Ω) when the EN pin is driven LOW. This auto-discharge function pulls the output voltage to <10% of nominal within 300 µs, preventing floating voltages that could cause latch-up or false wake-up in downstream circuitry. The LD6816CX4/36P,315 implements this without external components, distinguishing it from "H" variants which enter high-ohmic state.

What output capacitor is required for stable operation of the LD6816CX4/36P,315?

The LD6816CX4/36P,315 requires a minimum 0.7 µF ceramic output capacitor, with 1.0 µF recommended (X7R dielectric, ±30% tolerance). Equivalent Series Resistance (ESR) must be between 5 mΩ and 500 mΩ. This capacitor ensures loop stability, controls startup/shutdown transients, and maintains PSRR performance. Using less than 0.7 µF risks oscillation; exceeding 500 mΩ ESR degrades transient response. The LD6816CX4/36P,315 datasheet specifies these values for all operating conditions.

How does the LD6816CX4/36P,315 compare to standard LDOs in terms of dropout voltage and efficiency?

The LD6816CX4/36P,315 achieves a typical dropout voltage of 45 mV at 150 mA-significantly lower than conventional LDOs (often >200 mV). This enables operation with VIN as low as 3.645 V while maintaining 3.6 V output, extending usable battery voltage range by up to 120 mV in single-cell Li-ion systems. Its PMOS pass element contributes to this efficiency gain, and the LD6816CX4/36P,315 sustains this performance across −40°C to +85°C ambient.

Is the LD6816CX4/36P,315 RoHS-compliant and suitable for consumer-grade applications?

Yes, the LD6816CX4/36P,315 is Pb-free, RoHS-compliant, halogen- and antimony-free (dark green compliant), and qualified per NXP's NX1-00023 specification for consumer applications. It features 10 kV HBM ESD protection and operates reliably from −40°C to +85°C ambient temperature. The LD6816CX4/36P,315 is rated for continuous use in smartphones, cameras, and portable media players per its product data sheet Rev. 1 (2012).