NXP Semiconductors LD6816CX4/22H,315

Overview

LD6816CX4/22H,315 from NXP Semiconductors is a 2.2 V fixed-output, 150 mA ultra-low-dropout linear regulator in WLCSP4 package, featuring 45 mV dropout at full load, 30 µV_RMS output noise (10 Hz–100 kHz), and high-ohmic (3-state) output during disable-designed for power-sensitive mobile interfaces in smartphones and portable media players.

For engineers reviewing the LD6816CX4/22H,315 datasheet, LD6816CX4/22H,315 pinout, LD6816CX4/22H,315 application, or LD6816CX4/22H,315 equivalent, key selection criteria include dropout voltage under 150 mA load, enable threshold compatibility with 1.1 V logic, thermal performance in 0.76 mm × 0.76 mm footprint, and stability with 1.0 µF X7R output capacitor.

Technical Context

The LD6816CX4/22H,315 uses a PMOS pass transistor architecture enabling ultra-low dropout operation down to 45 mV at 150 mA, with internal reference generator and feedback loop optimized for fast transient response (<150 µs startup). Its enable input (VEN) operates independently of VIN, supporting active-HIGH control with VIH ≥1.1 V and VIL ≤0.4 V.

Thermal protection triggers at 160 °C junction temperature with 20 K hysteresis; overcurrent limiting caps peak output at 300 mA (for VO(nom) ≥1.8 V) and short-circuit current at 600 mA. The device maintains ±0.5% output accuracy at 25 °C and ±3% over −40 °C to +85 °C ambient.

Key Specifications

Pinout & Package

Package: Wafer-Level Chip-Scale Package (WLCSP4), 2×2 bump array, 0.4 mm pitch, dimensions 0.76 mm × 0.76 mm × 0.47 mm, Pb-free/RoHS/halogen-free compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD6816CX4/22H,315, the XC6210B222MR-G trades miniaturization for assembly flexibility, while the RT9013-22GB sacrifices 205 mV in dropout and 20 µV_RMS noise margin-making LD6816CX4/22H,315 optimal for space-constrained, noise-critical, battery-optimized designs.

Availability

LD6816CX4/22H,315 is available at Aetrix Electronics and suitable for smartphone baseband power, portable media player audio codecs, Bluetooth LE SoC core supply, and digital camera sensor bias requiring stable component supply with guaranteed long-term availability.

Supply support for LD6816CX4/22H,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 electronics, with leadership in power management and RF technologies.

The LD6816 series was designed specifically for ultra-miniaturized, low-noise power delivery in portable consumer devices-emphasizing wafer-level packaging, sub-50 mV dropout, and integrated protection for high-reliability mobile applications.

FAQ

What is the maximum input voltage rating for LD6816CX4/22H,315?

The LD6816CX4/22H,315 supports a continuous input voltage range of 2.3 V to 5.5 V. Its absolute maximum transient rating is +6.0 V for durations up to 4 ms, as specified in Table 6 of the datasheet. Exceeding this limit risks permanent damage to the internal pass transistor and reference circuitry. Always verify input rail transients in your system using oscilloscope measurements before finalizing the LD6816CX4/22H,315 design-in.

Does LD6816CX4/22H,315 require an external output capacitor, and what type is recommended?

Yes, LD6816CX4/22H,315 requires an external 1.0 µF X7R ceramic capacitor on the OUT pin for stability and correct transient response. The datasheet specifies a minimum capacitance of 0.7 µF (±30% tolerance) and ESR between 5 mΩ and 500 mΩ. Using lower capacitance or inappropriate dielectric (e.g., Y5V) may cause oscillation or extended shutdown time. The LD6816CX4/22H,315's stability is validated only with X7R-grade capacitors meeting these parameters.

How does the high-ohmic disable mode of LD6816CX4/22H,315 function in system-level power sequencing?

When the EN pin of LD6816CX4/22H,315 is driven LOW (≤0.4 V), the output enters a true high-impedance (3-state) condition-neither sourcing nor sinking current. This prevents backfeeding into downstream circuits powered by other regulators, enabling safe multi-rail sequencing in complex portable devices. Unlike pull-down variants (e.g., LD6816CX4/22P), LD6816CX4/22H,315 does not auto-discharge the output node, so external bleed resistors may be needed if rapid voltage decay is required.

What is the thermal resistance (R_th(j-a)) of LD6816CX4/22H,315, and how can it be minimized in PCB layout?

The typical junction-to-ambient thermal resistance of LD6816CX4/22H,315 is 130 K/W under standard test conditions (2-layer PCB, 25 °C ambient). To minimize R_th(j-a), all four solder bumps must connect to large copper areas-preferably dedicated inner-layer thermal planes tied via multiple vias. Avoid solder-mask over the WLCSP4 footprint, and ensure GND (A1) has the largest copper pour. Layout optimization can reduce effective R_th(j-a) by up to 35%, directly extending safe operating current at elevated ambient temperatures.

Is LD6816CX4/22H,315 compatible with lead-free reflow processes, and what peak temperature is required?

Yes, LD6816CX4/22H,315 is qualified for lead-free reflow per J-STD-020C. As a small-volume WLCSP4 package (<350 mm³), its required peak reflow temperature is 260 °C (Table 18). The device has Moisture Sensitivity Level (MSL) 1, meaning it can be stored indefinitely at ≤30 °C/60% RH without baking. Always follow NXP's recommended reflow profile-including preheat, soak, and ramp rates-to prevent solder voiding or delamination in the LD6816CX4/22H,315 assembly process.