NXP Semiconductors SSL21084T/1,118

Overview

SSL21084T/1,118 from NXP Semiconductors is a high-voltage LED driver IC with integrated 600 V MOSFET, designed for buck-mode boundary conduction mode (BCM) operation in mains-powered LED lamps. It delivers ±5% LED current accuracy, supports direct PWM dimming, and features internal overtemperature, overcurrent, brownout, and output short protection. Used in 100–230 V AC input lighting systems requiring compact, high-efficiency (up to 95%) constant-current drive.

For engineers reviewing the SSL21084T/1,118 datasheet, SSL21084T/1,118 pinout, SSL21084T/1,118 application, or SSL21084T/1,118 equivalent, this page provides verified technical context, SO12 package mapping, valley-detection timing, R_DS(on) at 25 °C and 125 °C, ton(high) = 15 μs typ., and confirmed thermal lead configuration for PCB heat sinking.

Technical Context

The SSL21084T/1,118 operates as a peak-current-controlled BCM buck converter with zero-current switching (ZCS) turn-on and valley detection on the DRAIN pin to minimize capacitive losses. Its internal 600 V MOSFET has R_DS(on) = 5.0 Ω (T_J = 25 °C) and 7.5 Ω (T_J = 125 °C), enabling robust operation across universal AC inputs.

Startup uses an internal HV current source from the HV pin; steady-state supply derives from dV/dt coupling via the DVDT pin. Brownout protection is implemented via the TONMAX pin, where an external capacitor sets adjustable maximum on-time (ton(high) = 12.5–17.5 μs), and thermal management leverages four dedicated GND thermal leads (pins 2, 6, 10, 11) in the SO12 package.

Key Specifications

Pinout & Package

SSL21084T/1,118 is housed in a plastic small outline package with 12 leads (SO12), body width 3.9 mm, outline SOT1196-1. Four pins (2, 6, 10, 11) serve as thermal GND leads to enhance PCB copper heat sinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SSL21083T/1,118, SSL21084T/1,118 adds configurable brownout protection via TONMAX-critical for universal-input luminaires subject to wide line-voltage variation. Versus MP4008GN-Z, it reduces component count by integrating the 600 V switch and dV/dt supply, cutting PCB area by ≥30%.

Availability

SSL21084T/1,118 is available at Aetrix Electronics and suitable for residential LED retrofits, commercial downlights, and industrial high-bay lighting requiring stable component supply, long-lifetime reliability, and universal AC input support.

Supply support for SSL21084T/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 leader focused on secure connectivity solutions for automotive, industrial, and IoT markets, with deep expertise in power management and lighting control ICs.

The SSL2108X family was designed specifically for cost-sensitive, high-efficiency LED lighting applications demanding minimal external components, integrated protection, and compatibility with standard wall dimmers and thermal management practices.

FAQ

What is the maximum drain voltage rating of the SSL21084T/1,118?

The SSL21084T/1,118 features an integrated 600 V MOSFET, with V_DRAIN rated up to +600 V. This allows direct connection to rectified 230 V AC mains (peak ~325 V) with sufficient margin for transients and line surges, eliminating the need for external HV switches in most general lighting applications.

How does the SSL21084T/1,118 implement thermal protection for LEDs?

The SSL21084T/1,118 uses its NTC pin to monitor LED temperature via an external NTC thermistor. When the sensed voltage falls below V_th(low)NTC (0.35 V typ.), output current is linearly reduced; below V_act(tmr)NTC (0.3 V typ.), a timer initiates thermal shutdown if the condition persists beyond 44 μs. This ensures precise, safe LED junction temperature control without external circuitry.

Can the SSL21084T/1,118 be used with 120 V AC input?

Yes, the SSL21084T/1,118 supports 100 V, 120 V, and 230 V AC inputs as specified in Table 3. Its boundary conduction mode operation, wide V_CC range (8.0–15.5 V), and adjustable brownout protection via the TONMAX pin ensure stable LED current regulation across all these mains voltages without hardware changes.

What is the purpose of the four GND pins in the SSL21084T/1,118 SO12 package?

Pins 2, 6, 10, and 11 of the SSL21084T/1,118 are dedicated thermal GND leads. They provide low-impedance paths from the die to the PCB copper plane, reducing thermal resistance from junction to ambient to 121 K/W (typ.). This enables higher continuous power dissipation (1 W) and extends operational lifetime in thermally constrained LED lamp housings.

Does the SSL21084T/1,118 require an external Zener diode on the VCC pin?

No. The SSL21084T/1,118 includes an internal active Zener clamp that limits V_CC to 14 V maximum. As long as the dV/dt supply current exceeds the IC's 1.3 mA operating consumption (plus gate drive load), no external Zener diode is needed-simplifying the bill of materials and improving reliability.