NXP Semiconductors SSL21082T/1,118

Overview

SSL21082T/1,118 from NXP Semiconductors is a high-voltage LED driver IC for mains-dimmable retrofit LED lamps operating in Boundary Conduction Mode (BCM). It integrates an internal HV switch, supports buck topology, delivers up to 90% efficiency, maintains power factor >0.9, and enables compact non-isolated designs using single inductor with internal demagnetization detection.

For engineers reviewing the SSL21082T/1,118 datasheet, SSL21082T/1,118 pinout, SSL21082T/1,118 application, or SSL21082T/1,118 equivalent, key selection considerations include its 300 V DRAIN breakdown voltage, 2.3 Ω typical R_DS(on) at 25 °C, 100 kHz conversion frequency, integrated valley detection, and support for both leading- and trailing-edge phase-cut dimmers in 100–120 V AC input systems.

Technical Context

The SSL21082T/1,118 implements a peak-current-controlled BCM buck converter with quasi-resonant valley switching-detecting minimum drain voltage to reduce capacitive switching losses. Its internal dV/dt supply draws power directly from the DRAIN node, eliminating auxiliary windings.

It features cycle-by-cycle current control for zero LED current overshoot/undershoot, dedicated thermal protection via NTC pin with dual-threshold response (0.35 V low threshold, 0.5 V high threshold), and brownout protection limiting maximum on-time to 15 µs when input voltage approaches output level.

Key Specifications

Pinout & Package

SSL21082T/1,118 is housed in SO12 (SOT1196-1) package: plastic small outline, 12-lead, 3.9 mm body width, with thermal GND pins (2, 6, 7, 10, 11) enhancing PCB heat sinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LED driver applications.

Compared with SSL21084T/1,118, the SSL21082T/1,118 provides optimized performance for 100–120 V AC systems with lower system cost and smaller footprint; versus UCC28810DR, it reduces component count and simplifies layout at the expense of external FET flexibility.

Availability

SSL21082T/1,118 is available at Aetrix Electronics and suitable for LED retrofit lamps, GU10 dimmable bulbs, and 100 V AC LED tubes requiring stable component supply, long-lifecycle support, and compliance with IEC 61000-3-2 harmonic standards.

Supply support for SSL21082T/1,118 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 applications.

The SSL21082T/1,118 belongs to NXP's SSL (Solid-State Lighting) family-designed specifically for cost-effective, high-efficiency, dimmable LED drivers in compact retrofit lamp form factors targeting residential and commercial lighting markets.

FAQ

What is the maximum input voltage the SSL21082T/1,118 can handle directly?

The SSL21082T/1,118 supports up to 300 V on its DRAIN pin and 600 V on its HV pin, making it suitable for direct connection to rectified 120 V AC mains (≈170 V DC peak). It is not rated for 230 V AC (≈325 V DC peak) without external clamping-use SSL21084T/1,118 for 230 V AC systems. The internal VCC clamp limits supply voltage to 20 V, protecting internal circuitry regardless of input transients.

Does the SSL21082T/1,118 require an external MOSFET?

No-the SSL21082T/1,118 integrates a high-voltage switch driver but does not include a power MOSFET. It drives an external high-side N-channel MOSFET connected to the DRAIN pin. The IC itself contains only control logic, valley detection, protection circuits, and gate drivers; the external MOSFET must be selected for 300 V V_DS, appropriate R_DS(on), and thermal capability per the application's power level.

How does the SSL21082T/1,118 achieve high power factor without active PFC?

The SSL21082T/1,118 achieves >0.9 power factor through Boundary Conduction Mode (BCM) operation combined with valley switching and optimized current shaping across the AC half-cycle. Its peak-current control and fixed-frequency timing ensure input current closely follows the sinusoidal input voltage waveform-meeting IEC 61000-3-2 Class C requirements for lighting without needing a separate boost PFC stage.

Can the SSL21082T/1,118 be used in isolated topologies?

Yes-the SSL21082T/1,118 supports both isolated (e.g., flyback) and non-isolated (buck, buck-boost) configurations. In isolated designs, it controls the primary-side switch while relying on secondary-side feedback via optocoupler or auxiliary winding sensing. Its valley detection and dV/dt supply remain functional, though DRAIN pin voltage swing characteristics differ due to transformer coupling.

What protection features are integrated into the SSL21082T/1,118?

The SSL21082T/1,118 integrates UnderVoltage LockOut (UVLO), Leading-Edge Blanking (LEB), OverCurrent Protection (OCP), Short-Winding Protection (SWP), Brownout protection, Internal OverTemperature Protection (OTP), Output Short Protection (OSP), and optional external OverVoltage Protection (OVP). All protections trigger latched or auto-restart behavior with defined thresholds-e.g., OTP activates at 170 °C and releases at 100 °C, ensuring robust thermal management in enclosed lamp housings.