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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

NXP Semiconductors LD6816CX4/28P,315

Name: LD6816CX4/28P,315
Brand: NXP Semiconductors
SKU: LD6816CX4/28P,315
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: LD6816CX4/28P,315

Manufacturer:: NXP Semiconductors

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: 4-XFBGA, WLCSP

Datasheet:: LD6816CX4/28P,315.pdf

Description:: IC REG LINEAR 2.8V 150MA 4WLCSP

Quantity:: RFQ Add To RFQ list

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Inventory:18,000

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Product details

Overview

LD6816CX4/28P,315 from NXP Semiconductors is a 2.8 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 auto-discharge functionality via integrated pull-down transistor. It operates from 2.3 V to 5.5 V input and delivers stable power to noise-sensitive analog/digital cores in space-constrained mobile devices.

For engineers reviewing the LD6816CX4/28P,315 datasheet, LD6816CX4/28P,315 pinout, LD6816CX4/28P,315 application, or LD6816CX4/28P,315 equivalent, key selection criteria include its 2.8 V fixed output, 0.76 mm × 0.76 mm WLCSP footprint, <150 µs startup time, 55 dB PSRR at 1 kHz, and guaranteed auto-discharge behavior during disable-critical for battery-powered systems requiring rapid rail collapse.

Technical Context

The LD6816CX4/28P,315 implements a PMOS pass transistor architecture enabling ultra-low dropout (45 mV @ 150 mA) and high PSRR (55 dB @ 1 kHz). Its enable input (active HIGH) controls both regulation and the integrated pull-down switch, ensuring low-ohmic output discharge when disabled-distinct from high-ohmic H-variants.

Designed for portable electronics, it integrates over-temperature shutdown (160 °C trigger, 20 K hysteresis), current limiting (600 mA short-circuit protection), and ESD robustness (±10 kV HBM). The 1 µF minimum output capacitor requirement and 5–500 mΩ ESR range ensure stability across temperature and load transients.

Key Specifications

Parameter	Value and Actual Design Meaning
Output voltage	Fixed 2.8 V ±2% over −40 °C to +85 °C ambient; enables direct replacement of 2.8 V logic rails without external feedback.
Dropout voltage	45 mV typical at 150 mA load; allows operation with VIN as low as 2.845 V, maximizing battery runtime in single-cell Li-ion systems.
PSRR	55 dB at 1 kHz; suppresses switching noise from upstream DC-DC converters feeding sensitive RF or audio circuitry.
Output noise	30 µV_RMS (10 Hz–100 kHz); supports low-noise analog sensors and precision ADC references without additional filtering.
Quiescent current	0.1 µA typical in shutdown (VEN ≤ 0.4 V); minimizes leakage current in always-on subsystems like real-time clocks.
Startup time	<150 µs to 95% of 2.8 V; meets fast wake-up requirements in mobile SoC power domains.
Pull-down resistance	100 Ω typical; actively discharges output capacitance to <10% VOUT within 300 µs, preventing floating states during sleep transitions.

Pinout & Package

LD6816CX4/28P,315 uses a 0.4 mm pitch Wafer-Level Chip-Scale Package (WLCSP4), measuring 0.76 mm × 0.76 mm × 0.47 mm, with four solder bumps arranged in a 2×2 grid. The package is Pb-free, RoHS-compliant, halogen- and antimony-free (dark green compliant).

Pin/Terminal	Circuit Role	Design Meaning
GND (A1)	Supply ground reference	Primary return path for regulator current; must connect to solid ground plane for thermal and noise performance.
EN (A2)	Enable control input	Active HIGH logic input (VIH ≥ 1.1 V); asserts internal pass transistor and pull-down switch simultaneously.
OUT (B1)	Regulated output voltage	2.8 V supply node; requires ≥1.0 µF X7R ceramic capacitor with 5–500 mΩ ESR for stability and fast discharge.
IN (B2)	Input voltage supply	Accepts 2.3–5.5 V; decoupling capacitor recommended close to pin to reduce input ripple coupling.

Key Features

Feature	Design Value
Auto-discharge function	Integrated 100 Ω pull-down transistor ensures rapid output collapse (<300 µs to 10% VOUT) upon disable-eliminates need for external bleed resistors in battery-critical designs.
Ultra-low noise regulation	30 µV_RMS output noise (10 Hz–100 kHz) enables clean power for RF transceivers, audio codecs, and high-resolution ADCs without post-regulation filtering.
High PSRR at low frequency	55 dB rejection at 1 kHz suppresses ripple from buck converter switching frequencies and their harmonics, improving signal integrity in mixed-signal SoCs.
Thermal and current protection	160 °C over-temperature shutdown with 20 K hysteresis and 600 mA short-circuit current limit prevent damage during fault conditions without external supervision.
Miniaturized WLCSP packaging	0.76 mm × 0.76 mm footprint saves >70% board area vs. SOT-23 packages-ideal for smartphones, wearables, and compact IoT modules.

Applications

Smartphone Application Processor Core Rail	Bluetooth Low Energy (BLE) SoC Power Domain
Use Scenario: Powers 2.8 V I/O or core voltage domain of application processors during active and low-power modes. IC Role / Device Role / Timing Role: Primary LDO delivering regulated 2.8 V with fast transient response and auto-discharge during deep-sleep entry. Use Value: Enables sub-100 µs wake-up latency and eliminates residual charge on processor I/O lines that could cause leakage or state corruption.	Use Scenario: Supplies 2.8 V to BLE radio transceiver and digital baseband in wearable sensors. IC Role / Device Role / Timing Role: Low-noise, low-quiescent LDO with integrated pull-down for controlled power sequencing during radio sleep/wake cycles. Use Value: 30 µV_RMS noise preserves RF sensitivity; 0.1 µA shutdown current extends coin-cell battery life beyond 2 years.
Digital Camera Image Sensor Bias Supply	Portable Medical Pulse Oximeter Analog Front-End
Use Scenario: Provides clean 2.8 V bias to CMOS image sensor analog circuits and ADC reference buffers. IC Role / Device Role / Timing Role: Ultra-low-noise LDO isolating sensor analog chain from noisy digital supply rails. Use Value: 55 dB PSRR and 30 µV_RMS noise directly reduce image fixed-pattern noise and improve dynamic range by ≥2 bits.	Use Scenario: Powers op-amps, photodiode transimpedance stages, and 24-bit sigma-delta ADC in battery-operated pulse oximeters. IC Role / Device Role / Timing Role: Precision LDO with tight output tolerance (±2%) and minimal drift over temperature. Use Value: Maintains measurement accuracy across −20 °C to +50 °C operating range without calibration drift; WLCSP footprint enables miniaturized PCB layout.

Smartphone Application Processor Core Rail

Bluetooth Low Energy (BLE) SoC Power Domain

Use Scenario: Powers 2.8 V I/O or core voltage domain of application processors during active and low-power modes.

IC Role / Device Role / Timing Role: Primary LDO delivering regulated 2.8 V with fast transient response and auto-discharge during deep-sleep entry.

Use Value: Enables sub-100 µs wake-up latency and eliminates residual charge on processor I/O lines that could cause leakage or state corruption.

Use Scenario: Supplies 2.8 V to BLE radio transceiver and digital baseband in wearable sensors.

IC Role / Device Role / Timing Role: Low-noise, low-quiescent LDO with integrated pull-down for controlled power sequencing during radio sleep/wake cycles.

Use Value: 30 µV_RMS noise preserves RF sensitivity; 0.1 µA shutdown current extends coin-cell battery life beyond 2 years.

Digital Camera Image Sensor Bias Supply

Portable Medical Pulse Oximeter Analog Front-End

Use Scenario: Provides clean 2.8 V bias to CMOS image sensor analog circuits and ADC reference buffers.

IC Role / Device Role / Timing Role: Ultra-low-noise LDO isolating sensor analog chain from noisy digital supply rails.

Use Value: 55 dB PSRR and 30 µV_RMS noise directly reduce image fixed-pattern noise and improve dynamic range by ≥2 bits.

Use Scenario: Powers op-amps, photodiode transimpedance stages, and 24-bit sigma-delta ADC in battery-operated pulse oximeters.

IC Role / Device Role / Timing Role: Precision LDO with tight output tolerance (±2%) and minimal drift over temperature.

Use Value: Maintains measurement accuracy across −20 °C to +50 °C operating range without calibration drift; WLCSP footprint enables miniaturized PCB layout.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
Torex XC6219B282MR-G	2.8 V fixed output, 150 mA, 65 mV dropout (typ), no auto-discharge; SOT-25 package (2.9 mm × 2.8 mm).	Lacks integrated pull-down; requires external resistor network for discharge, increasing BOM count and board area.	Select when cost sensitivity outweighs size constraints and auto-discharge is handled externally.
Richtek RT9013-28GB	2.8 V fixed output, 500 mA, 250 mV dropout (typ), 45 µV_RMS noise, no auto-discharge; DFN-6 (2.0 mm × 2.0 mm).	Higher current capability but higher dropout and noise; no integrated discharge switch.	Choose for higher load margin where 250 mV dropout is acceptable and discharge is managed by system-level control.

Compared with XC6219B282MR-G and RT9013-28GB, LD6816CX4/28P,315 uniquely combines ultra-low dropout (45 mV), ultra-low noise (30 µV_RMS), and monolithic auto-discharge in a 0.76 mm² WLCSP-enabling smaller, quieter, and faster-waking portable systems without design compromises.

Availability

LD6816CX4/28P,315 is available at Aetrix Electronics and suitable for smartphone power management, BLE wearable subsystems, digital camera sensor biasing, and portable medical device analog front-ends requiring stable component supply and long-term lifecycle support.

Supply support for LD6816CX4/28P,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, RF, and embedded security.

The LD6816 series was designed specifically for ultra-miniaturized, battery-powered portable devices demanding ultra-low dropout, low noise, and fast, controlled power sequencing-targeting smartphones, wearables, and IoT edge nodes.

FAQ

What is the nominal output voltage of the LD6816CX4/28P,315?

The LD6816CX4/28P,315 provides a fixed 2.8 V output voltage with ±2% tolerance over −40 °C to +85 °C ambient temperature and 1 mA to 150 mA load current. This value is laser-marked as "Q" on the WLCSP die and confirmed in Table 4 of the NXP datasheet for /28P variants.

Does the LD6816CX4/28P,315 support auto-discharge, and how does it work?

Yes, the LD6816CX4/28P,315 includes an integrated pull-down transistor that activates when the EN pin is driven LOW, creating a low-ohmic path from OUT to GND. Its typical pull-down resistance is 100 Ω, collapsing the output voltage to 10% of 2.8 V within 300 µs-enabling rapid rail discharge without external components.

What is the minimum output capacitance required for stable operation of the LD6816CX4/28P,315?

The LD6816CX4/28P,315 requires a minimum 0.7 µF external ceramic output capacitor (X7R dielectric recommended), with a typical value of 1.0 µF specified in Table 10. Capacitor ESR must be between 5 mΩ and 500 mΩ to ensure phase margin and prevent oscillation across temperature and load conditions.

What is the thermal resistance (R_th(j-a)) of the LD6816CX4/28P,315, and how does PCB layout affect it?

The typical junction-to-ambient thermal resistance of the LD6816CX4/28P,315 is 130 K/W under standard two-layer PCB conditions. Layout significantly impacts this value: connecting all pins-especially GND-to large copper planes and using multiple vias to inner ground/power layers reduces effective R_th(j-a) and prevents thermal shutdown at 150 mA continuous load.

Is the LD6816CX4/28P,315 compatible with lead-free reflow soldering processes?

Yes, the LD6816CX4/28P,315 is qualified for lead-free reflow per J-STD-020C. Its WLCSP4 package (volume <350 mm³, thickness <1.6 mm) requires a peak reflow temperature of 260 °C. Moisture sensitivity level (MSL) compliance must be observed-baking per MSL rating is mandatory before reflow if exposed beyond floor life.

LD6816CX4/28P,315 Specifications

Product attributes: Attribute value

Manufacturer:: NXP Semiconductors

Series:: -

Package/Case:: 4-XFBGA, WLCSP

Packaging:: Bulk

Product Status:: Obsolete

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 5.5V

Voltage - Output (Min/Fixed):: 2.8V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.075V @ 150mA

Current - Output:: 150mA

Current - Quiescent (Iq):: 100 µA

Current - Supply (Max):: 250 µA

PSRR:: 55dB (1kHz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature, Transient Voltage

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 4-WLCSP (0.76x0.76)

LD6816CX4/28P,315 FAQ

1.How can I place an order for LD6816CX4/28P,315 through Aetrix?

Please submit a Request for Quotation (RFQ) for LD6816CX4/28P,315 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for LD6816CX4/28P,315 reliable?

The price and inventory of LD6816CX4/28P,315 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD6816CX4/28P,315 is usually 5 days.

3.What payment methods are accepted for LD6816CX4/28P,315?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD6816CX4/28P,315 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for LD6816CX4/28P,315?

LD6816CX4/28P,315 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your LD6816CX4/28P,315 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for LD6816CX4/28P,315?

For technical support, including LD6816CX4/28P,315 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD6816CX4/28P,315 requirements.

6.How does Aetrix verify that LD6816CX4/28P,315 is sourced from the original manufacturer or authorized distributors?

All LD6816CX4/28P,315 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LD6816CX4/28P,315 meets industry standards.

7.What is the process for return or replacement of LD6816CX4/28P,315?

All LD6816CX4/28P,315 units undergo pre-shipment inspection (PSI). If there is an issue with LD6816CX4/28P,315, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The LD6816CX4/28P,315 part is unused and in its original packaging.

Return procedure for LD6816CX4/28P,315:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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