NXP Semiconductors SSL1523AP/N2,112

Overview

SSL1523AP/N2,112 from NXP Semiconductors is a high-voltage SMPS controller IC with integrated 650 V / 6.5 Ω DMOS power switch, designed for primary-side-controlled flyback LED drivers up to 15 W. It operates directly from rectified universal AC mains (80–276 V), incorporates valley switching for minimized turn-on loss, and supports both primary-sensing and optocoupler-based secondary feedback in DIP8 packaging.

For engineers reviewing the SSL1523AP/N2,112 datasheet, SSL1523AP/N2,112 pinout, SSL1523AP/N2,112 application, or SSL1523AP/N2,112 equivalent, key selection criteria include its integrated high-voltage switch, valley-switching timing control via AUX/RC pins, thermal/overcurrent/undervoltage protection architecture, and suitability for retrofit LED lamp and commercial lighting power supplies requiring <100 mW standby power.

Technical Context

The SSL1523AP/N2,112 implements voltage-mode control in a self-oscillating (SOPS) or externally frequency-adjusted mode using an RC oscillator on pin RC. Its valley switching logic monitors drain ringing via pin AUX to initiate primary strokes at minimum drain voltage-reducing capacitive switching losses across 200–800 kHz ringing frequencies.

Start-up is enabled by high-voltage current sourced from pin DRAIN; operation transitions to auxiliary winding supply once VCC exceeds 9.5 V, with undervoltage lockout halting switching below 7.5 V. Protection includes cycle-by-cycle OCP via external source resistor RI, OTP triggering at 160 °C, and overvoltage clamping on pin REG.

Key Specifications

Pinout & Package

SSL1523AP/N2,112 is housed in a plastic dual in-line package (DIP8), SOT97-1 outline, with 300-mil lead spacing and GND pins (pins 2 and 7) optimized for thermal dissipation on PCB copper pours.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SMPS controller applications.

Compared with UCC28810DR and FL7730MX, the SSL1523AP/N2,112 uniquely combines integrated 650 V switching, RC-tunable frequency, and hardware-based valley detection in DIP8-enabling higher efficiency, lower EMI, and simpler transformer design for universal-input LED drivers up to 15 W.

Availability

SSL1523AP/N2,112 is available at Aetrix Electronics and suitable for retro-fit LED lamps, commercial cabinet lighting, and contour lighting requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for SSL1523AP/N2,112 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 Dutch semiconductor manufacturer specializing in secure connectivity solutions, automotive systems, and power management ICs for industrial and consumer applications.

The SSL1523A product line targets cost-sensitive, high-efficiency LED driver designs for mains-powered lighting-emphasizing integration, protection, and ease of certification in Class II isolated topologies.

FAQ

What is the maximum continuous drain voltage rating for SSL1523AP/N2,112?

The SSL1523AP/N2,112 features a built-in DMOS transistor with a guaranteed breakdown voltage of 650 V on pin DRAIN, validated per IEC 60134 limiting values. This rating enables direct connection to rectified universal AC mains up to 276 V RMS without external snubbers or voltage clamping networks in properly designed flyback converters.

How does SSL1523AP/N2,112 achieve valley switching without external timing components?

The SSL1523AP/N2,112 implements valley switching through dedicated internal circuitry that monitors drain node ringing via pin AUX. After secondary demagnetization ends, the IC detects the first valley in the resonant drain waveform and triggers the next primary stroke-eliminating need for external comparators or timing ICs while minimizing capacitive turn-on loss across 200–800 kHz ringing frequencies.

Can SSL1523AP/N2,112 operate with only primary-side sensing, or is optocoupler feedback mandatory?

The SSL1523AP/N2,112 supports both configurations: it functions as a basic voltage source using primary-side sensing alone (e.g., reflected voltage on AUX), or as a precision constant-current source with optocoupler-coupled secondary feedback applied to pin REG. Primary sensing remains active during optocoupler failure, ensuring inherent overvoltage protection.

What is the recommended external capacitor value for the RC oscillator on SSL1523AP/N2,112?

NXP specifies a maximum oscillator capacitor value of approximately 1 nF on pin RC to ensure reliable charging within the oscillator's charge time window. Using larger capacitors may cause unstable frequency behavior or failure to start; typical designs use 100–470 pF with matching resistors to achieve target frequencies between 10–200 kHz.

Does SSL1523AP/N2,112 include thermal shutdown, and what is the trip temperature?

Yes, SSL1523AP/N2,112 includes accurate junction temperature protection with a nominal trip point of 160 °C and 2 °C hysteresis. When triggered, the IC halts switching and reduces supply current to start-up levels until temperature falls below 158 °C, then resumes normal operation-preventing permanent damage during sustained overload or poor heatsinking conditions.