NXP Semiconductors LD6805K/18P,115

Overview

LD6805K/18P,115 from NXP Semiconductors is a 1.8 V fixed-output, 150 mA low-dropout (LDO) regulator with ultra-high PSRR (75 dB at 1 kHz), 250 mV dropout at full load, and auto-discharge functionality enabled via integrated pull-down transistor. It operates from 2.3 V to 5.5 V input and targets power-sensitive analog/digital interfaces in portable consumer electronics.

For engineers reviewing the LD6805K/18P,115 datasheet, LD6805K/18P,115 pinout, LD6805K/18P,115 application, or LD6805K/18P,115 equivalent, key selection criteria include its 1.8 V output accuracy (±2% over temperature), 40 µV_RMS output noise, 150 µs startup time, and DFN1010C-4 package compatibility with space-constrained mobile PCB layouts.

Technical Context

The LD6805K/18P,115 implements a CMOS-based LDO architecture with internal voltage reference, error amplifier, and pass transistor-optimized for high PSRR and low noise. Its enable input (active HIGH) controls both regulation and the integrated pull-down switch that actively discharges the output during shutdown.

This device uses monolithic silicon technology and features built-in overcurrent protection, thermal shutdown, and 6 kV HBM ESD protection. The 1 × 1 × 0.55 mm DFN1010C-4 (SOT1194-1) package includes an exposed thermal pad (TAB) connected to GND for enhanced thermal performance.

Key Specifications

Pinout & Package

LD6805K/18P,115 is housed in a 1 × 1 × 0.55 mm DFN1010C-4 (SOT1194-1) plastic package with wettable flanks and an exposed thermal pad (TAB) on the underside, electrically connected to GND. Thermal performance requires soldering the TAB to a GND copper plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B182MR-G and RT9013-18GB, the LD6805K/18P,115 uniquely combines 1.8 V precision, ultra-low noise, high PSRR, and integrated auto-discharge in a 1 mm² footprint-making it optimal for miniaturized, noise-critical, and fast-sequencing portable designs.

Availability

LD6805K/18P,115 is available at Aetrix Electronics and suitable for smartphone baseband power, digital camera sensor bias, portable media player audio codec, wearable health sensor hub, and other portable electronics requiring stable component supply with tight voltage tolerance and ultra-low noise.

Supply support for LD6805K/18P,115 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 headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and consumer markets.

The LD6805 series belongs to NXP's high-performance analog power management portfolio, designed specifically for ultra-compact, low-noise, and high-PSRR LDO applications in battery-powered portable devices.

FAQ

What is the output voltage tolerance of the LD6805K/18P,115 across temperature?

The LD6805K/18P,115 delivers a nominal 1.8 V output with ±2% tolerance over the full operating temperature range of −40 °C to +85 °C. At +25 °C, the variation tightens to ±0.5%, ensuring precise biasing for voltage-sensitive analog circuits and low-voltage logic interfaces in portable systems using the LD6805K/18P,115.

Does the LD6805K/18P,115 require an external output capacitor, and what value is recommended?

Yes, the LD6805K/18P,115 requires an external output capacitor for stability and transient response. The datasheet specifies a minimum of 0.7 µF and recommends 1.0 µF X7R ceramic with ESR between 5 mΩ and 500 mΩ. Using 1.0 µF ensures proper startup, shutdown timing, and PSRR performance-critical for reliable operation of the LD6805K/18P,115 in production designs.

How does the auto-discharge function work in the LD6805K/18P,115?

When the EN pin is driven LOW, the LD6805K/18P,115 disables regulation and activates an internal ~100 Ω pull-down transistor between OUT and GND. This rapidly discharges the output capacitance (tsd(reg) ≈ 300 µs with 1 µF CL), preventing floating voltages that could cause unintended behavior in downstream circuitry-a key advantage over high-ohmic LDOs like the LD6805K/18H variants. This feature is intrinsic to the LD6805K/18P,115 design.

What is the thermal resistance (R_th(j-a)) of the LD6805K/18P,115, and how can it be optimized?

The typical junction-to-ambient thermal resistance of the LD6805K/18P,115 in a standard two-layer PCB layout is 250 K/W. To optimize thermal performance, the exposed TAB (GND) must be soldered to a large copper pour connected to the system ground plane via multiple vias. Avoid solder mask under the device and ensure solid copper connections on all pins-practices essential for sustaining 150 mA continuous output in the LD6805K/18P,115.

Is the LD6805K/18P,115 compatible with lead-free reflow processes?

Yes, the LD6805K/18P,115 is qualified for lead-free reflow soldering per J-STD-020C. Its DFN1010C-4 package falls into the <1.6 mm thickness and <350 mm³ volume category, requiring a peak reflow temperature of 260 °C. The device is RoHS-compliant, Pb-free, and halogen-free-fully aligned with modern environmental compliance standards for the LD6805K/18P,115.