NXP Semiconductors LD6816CX4/22P,315

Overview

LD6816CX4/22P,315 from NXP Semiconductors is a 2.2 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, enabling stable power for noise-sensitive analog rails in space-constrained mobile devices.

For engineers reviewing the LD6816CX4/22P,315 datasheet, LD6816CX4/22P,315 pinout, LD6816CX4/22P,315 application, or LD6816CX4/22P,315 equivalent, key selection criteria include its 2.2 V output accuracy (±0.5% at +25°C), sub-150 µs startup time, 0.1 µA shutdown quiescent current, and integrated thermal/current protection - all critical for battery-powered portable electronics requiring fast enable control and rapid output discharge.

Technical Context

The LD6816CX4/22P,315 implements a PMOS pass transistor architecture enabling ultra-low dropout operation down to 45 mV at 150 mA, minimizing input-to-output voltage overhead and maximizing efficiency in low-voltage systems. Its internal reference and error amplifier maintain tight output regulation across −40°C to +85°C ambient.

Unlike high-ohmic disable variants (e.g., /xxH), this /xxP version integrates a dedicated pull-down transistor on the OUT pin, ensuring active discharge of downstream capacitance during shutdown - a requirement for sequencing-critical subsystems like RF transceivers or camera modules where residual voltage must be cleared rapidly.

Key Specifications

Pinout & Package

LD6816CX4/22P,315 uses a 0.4 mm pitch Wafer-Level Chip-Scale Package (WLCSP4) measuring 0.76 mm × 0.76 mm × 0.47 mm, optimized for ultra-dense PCB layouts in smartphones and wearables.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B222MR-G and RT9013-22GB, LD6816CX4/22P,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 - making it optimal for miniaturized, sequencing-critical portable designs where board space and power-state transition fidelity are constrained.

Availability

LD6816CX4/22P,315 is available at Aetrix Electronics and suitable for smartphone baseband power, portable camera modules, wireless headset audio codecs, and wearable sensor hubs requiring stable component supply with guaranteed long-term availability.

Supply support for LD6816CX4/22P,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 leader focused on secure connectivity solutions for automotive, industrial, and consumer markets, with broad analog and power management IP.

The LD6816 series was designed specifically for ultra-miniaturized, battery-powered portable electronics - delivering ultra-low dropout, low noise, and integrated auto-discharge in wafer-level packaging to meet stringent size and power sequencing demands.

FAQ

What is the nominal output voltage and tolerance of LD6816CX4/22P,315?

The LD6816CX4/22P,315 provides a fixed 2.2 V output voltage with ±0.5% tolerance at +25°C and ±3% over −40°C to +85°C ambient. This accuracy is achieved through laser-trimmed internal resistor networks and is specified in Table 9 of the NXP datasheet under "ΔVO output voltage variation" for VOUT ≥1.8 V.

Does LD6816CX4/22P,315 support auto-discharge, and how does it work?

Yes, LD6816CX4/22P,315 includes an integrated pull-down transistor that activates when the EN pin is driven LOW, providing a low-ohmic path (typical R_pd = 100 Ω) from OUT to GND. This discharges external output capacitance in under 300 µs, as confirmed in Section 9.8 and Table 9 (t_sd(reg)) of the datasheet.

What is the minimum recommended output capacitor for stable operation of LD6816CX4/22P,315?

The LD6816CX4/22P,315 requires a minimum 0.7 µF X7R ceramic capacitor on the OUT pin, with recommended value of 1.0 µF and ESR between 5 mΩ and 500 mΩ. This is specified in Table 10 and Section 10.1 of the datasheet to ensure phase margin and transient response stability.

What is the thermal resistance (R_th(j-a)) of LD6816CX4/22P,315, and how does PCB layout affect it?

The typical junction-to-ambient thermal resistance of LD6816CX4/22P,315 is 130 K/W under standard two-layer PCB conditions (Table 8). Layout significantly impacts this value: connecting all pins - especially GND - to large copper areas and using vias to inner ground/power planes reduces effective R_th(j-a), as detailed in Section 7 footnote [1].

Is LD6816CX4/22P,315 RoHS-compliant and halogen-free?

Yes, LD6816CX4/22P,315 is Pb-free, RoHS-compliant, and fully halogen- and antimony-free (dark green compliant), as stated in Section 1.2 "Features and benefits" of the NXP product data sheet Rev. 1 (2012).