NXP Semiconductors LD6805K/18H,115

Overview

LD6805K/18H,115 from NXP Semiconductors is a 1.8 V fixed-output, 150 mA low-dropout (LDO) regulator in a 1×1 mm DFN package, featuring 75 dB PSRR at 1 kHz, 250 mV dropout at full load, and high-ohmic (3-state) output during disable mode. It operates from 2.3 V to 5.5 V input and delivers ultra-low 40 µV_RMS output noise for powering noise-sensitive analog circuits in portable devices.

For engineers reviewing the LD6805K/18H,115 datasheet, LD6805K/18H,115 pinout, LD6805K/18H,115 application, or LD6805K/18H,115 equivalent, this page provides verified technical context, validated pin functions, confirmed LDO performance metrics (PSRR, dropout, noise), real-world use cases in mobile interface power rails, and two rigorously cross-checked alternative parts with documented functional and application-level differences.

Technical Context

The LD6805K/18H,115 integrates a precision voltage reference, error amplifier, and PMOS pass transistor in monolithic silicon, enabling stable 1.8 V regulation across −40 °C to +85 °C ambient. Its enable input (active HIGH) controls a shutdown circuit that places the OUT pin in a high-impedance state, eliminating leakage paths in battery-powered systems.

Designed for miniaturized portable electronics, it uses a DFN1010C-4 (SOT1194-1) thermal-enhanced package with exposed thermal pad (TAB connected to GND), supporting ≤250 K/W junction-to-ambient thermal resistance when properly mounted on multi-layer PCBs with vias to internal ground planes.

Key Specifications

Pinout & Package

LD6805K/18H,115 is housed in a DFN1010C-4 (SOT1194-1) plastic package measuring 1.0 × 1.0 × 0.55 mm with an exposed thermal pad (TAB) on the underside, electrically connected to GND. The package is Pb-free, RoHS-compliant, halogen- and antimony-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD6805K/18H,115, TPS7A0518PDBVR offers lower noise and dropout but sacrifices 3-state disable functionality, while MCP1700T-1802E/TT trades PSRR and package size for higher current and broader availability-making LD6805K/18H,115 optimal for space-constrained, noise-critical portable applications requiring true high-Z shutdown.

Availability

LD6805K/18H,115 is available at Aetrix Electronics and suitable for smartphone baseband power, digital camera sensor bias, portable media player audio codecs, and Bluetooth LE SoC core supply requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for LD6805K/18H,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 electronics.

The LD6805 series belongs to NXP's high-PSRR, miniature LDO product line, engineered specifically for ultra-compact portable devices where board space, power efficiency, and noise immunity are critical design constraints.

FAQ

What is the exact output voltage tolerance of LD6805K/18H,115 over temperature?

The LD6805K/18H,115 delivers 1.8 V output with ±2% tolerance over −30 °C to +85 °C ambient temperature and ±0.5% at +25 °C. This specification is guaranteed per Table 8 in the official NXP datasheet Rev. 2 (25 June 2012), ensuring compatibility with 1.8 V I/O standards such as SDIO, MIPI D-PHY, and low-voltage logic families. The LD6805K/18H,115 maintains this accuracy without external trimming components.

Does LD6805K/18H,115 require an external output capacitor, and what are its minimum specifications?

Yes, LD6805K/18H,115 requires an external output capacitor for stability: minimum 0.7 µF, recommended 1.0 µF X7R ceramic with ESR between 5 mΩ and 500 mΩ. Per Section 10.1 and Table 9 of the datasheet, using capacitors outside this range risks oscillation or degraded transient response. The LD6805K/18H,115 does not support ceramic capacitors with zero-ESR polymer or tantalum alternatives due to phase margin constraints.

How does the high-ohmic disable mode of LD6805K/18H,115 function during system sleep?

When the EN pin voltage drops below 0.4 V, LD6805K/18H,115 disables its pass transistor and places the OUT pin in a high-impedance (3-state) condition-no internal pull-up or pull-down is activated. This prevents back-current flow into the LDO from downstream loads, enabling true power domain isolation. The LD6805K/18H,115 achieves this without external components, unlike variants with auto-discharge (e.g., LD6805K/18P).

What thermal considerations apply to LD6805K/18H,115 in a 2-layer PCB layout?

On a 2-layer PCB, LD6805K/18H,115 achieves a typical R_th(j-a) of 250 K/W only when the exposed TAB is soldered to a ≥100 mm² solid copper pour connected to GND with ≥4 thermal vias (0.3 mm diameter). Without this, junction temperature can exceed 125 °C at 150 mA load. The LD6805K/18H,115 datasheet explicitly warns against solder-mask coverage under the TAB (Section 7, Note [1]).

Is LD6805K/18H,115 compatible with lead-free reflow processes, and what peak temperature is required?

Yes, LD6805K/18H,115 is qualified for lead-free reflow per J-STD-020C. As a DFN1010C-4 package (volume <350 mm³, thickness <1.6 mm), it requires a peak reflow temperature of 260 °C (Table 13). The device's moisture sensitivity level (MSL) is not specified in the provided datasheet, but standard handling per MSL-1 is recommended unless otherwise indicated by NXP packaging labels.