Semtech Corporation SC445TETRT-01

Overview

SC445TETRT-01 from Semtech is a high-efficiency integrated boost WLED driver IC for 4-string backlighting, supporting 4.5V–27V input, 42V max output, 150mA per string, ±2% string-to-string current matching, and 700kHz switching frequency - deployed in notebook and automotive navigation displays.

For engineers reviewing the SC445TETRT-01 datasheet, pinout, applications, or equivalent options, key selection considerations include programmable LED current, open/short LED fault tolerance per string, thermal auto-recovery, adjustable OVP, and compatibility with medium-size LCD panels requiring stable multi-string current regulation.

Technical Context

The SC445TETRT-01 integrates a 3.0A internal power switch and operates a fixed-frequency (700kHz) current-mode boost converter to regulate four independent LED strings. Its fast transient response sustains input voltage slew rates up to 5V/µs, enabling robust operation in automotive and portable systems with unstable rails.

It implements per-string current sensing via dedicated IO1–IO4 terminals, supports dual dimming (PWM + analog), and features autonomous fault handling: open-circuit or short-circuit detection disables only the affected string while maintaining others - critical for display visibility continuity.

Key Specifications

Pinout & Package

SC445TETRT-01 is housed in a thermally enhanced TSSOP-20 EDP package (4.4mm × 6.5mm, 0.65mm pitch) with exposed thermal pad for PCB heat sinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-string WLED driver applications.

Compared with LM3409QMY/NOPB and TPS61165DRVR, the SC445TETRT-01 uniquely delivers integrated 4-string control with autonomous fault containment, making it the only option among the three that maintains partial display operation under LED failure - critical for automotive and premium portable displays.

Availability

SC445TETRT-01 is available at Aetrix Electronics and suitable for notebook display, automotive navigation display, and tablet computer display applications requiring stable component supply, long-term lifecycle support, and AEC-Q200-aligned reliability validation.

Supply support for SC445TETRT-01 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

Semtech Corporation is a U.S.-based semiconductor company specializing in high-performance analog and mixed-signal ICs for power management, optical networking, and sensing.

The SC445 product line targets energy-efficient, fault-resilient LED backlighting for medium-format LCDs in automotive, computing, and portable electronics - emphasizing integration, thermal robustness, and display continuity under fault.

FAQ

What is the maximum number of LEDs the SC445TETRT-01 can drive per string?

The SC445TETRT-01 supports up to 10 white LEDs per string, based on its 42V maximum output voltage and typical forward voltage of 4.2V per LED. This assumes series connection within each of the four independent strings. Exceeding 10 LEDs risks violating the OVP limit and triggering shutdown unless OVPIN is adjusted downward.

Does the SC445TETRT-01 support analog dimming in addition to PWM?

Yes, the SC445TETRT-01 supports both PWM dimming (0.2%–100% range) and analog dimming via the IOSET pin. Applying a variable voltage (0.2V–1.2V) to IOSET scales the reference current linearly, enabling smooth brightness control without PWM-induced flicker - especially useful in portable media players.

How does the SC445TETRT-01 handle an open-circuit condition in one LED string?

When an open-circuit fault is detected on any string (e.g., IO1–IO4 current drops to zero), the SC445TETRT-01 disables only that string's regulation loop while continuing normal operation of the remaining three strings. The FFLAG pin asserts low to signal the fault, preserving partial display illumination without system reset.

What thermal protection mechanism does the SC445TETRT-01 implement?

The SC445TETRT-01 incorporates junction-temperature-based thermal shutdown at approximately 150°C, with automatic recovery once the die cools below ~135°C. This hysteresis prevents oscillation and enables self-recovery in thermally constrained enclosures - a key advantage over latch-off alternatives requiring external reset.

Is the SC445TETRT-01 RoHS and REACH compliant?

Yes, the SC445TETRT-01 is lead-free, halogen-free, and compliant with both RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. It meets WEEE recycling requirements and carries the "Pb-Free" and "Green" markings per Semtech's packaging standards.