Panasonic ERJ-2RKF4990X 499 ohm 1% 0402 SMD Thick Film Resistor 20 PCS

Panasonic ERJ-2RKF4990X surface-mount thick-film resistor rated 499 ohms with ±1% tolerance in the compact 0402 / 1005 metric package.

The 499-ohm value is useful in precision signal networks, bias circuits, amplifier feedback, current limiting, LED support circuitry, digital interfaces, voltage dividers, and general board-level repair where a tighter tolerance than standard 5% resistor stock is required.

Original Mouser packaging identifies Panasonic ERJ-2RKF4990X, 0402 size, 499 ohms, thick-film construction, and country of origin China. The label shows date code 1746.

Lifecycle: ACTIVE.

HISTORICAL BACKGROUND: Panasonic traces its origins to 1918, when Konosuke Matsushita founded the business that later became one of Japan’s largest electronics manufacturers. Panasonic developed major product lines not only in consumer electronics but also in resistors, capacitors, relays, switches, sensors, batteries, semiconductors, and industrial electronic components.

The ERJ family became one of Panasonic’s widely used surface-mount resistor lines as electronic manufacturing moved toward automated PCB assembly. Thick-film construction uses a resistive material deposited onto a ceramic substrate and trimmed to the required resistance value, producing a compact and reliable component suitable for high-volume electronics.

The 0402 package became increasingly important as electronic systems moved toward smaller and denser circuit boards. At approximately 1.0 x 0.5 mm, this package allows high component density while maintaining reliable electrical performance in compact assemblies.

A 499-ohm value is a standard precision E-series value commonly used where designers need a controlled resistance close to 500 ohms but with tighter matching and repeatability. Applications include feedback networks, biasing, line termination, signal conditioning, sensor circuits, and precision analog support circuitry.

The ±1% tolerance makes this device more accurate than traditional ±5% general-purpose resistors and useful in circuits where resistor value directly influences gain, current, logic thresholds, or voltage ratios.