Active production — a current BOM fit
The TLC5947RHBR: This 24-channel constant-current sink LED driver delivers 30 mA per channel with a 30 V output compliance voltage, which covers the forward voltage stack of most backlight and sign LED strings without an external boost stage.
Shift-register interface and throughput
The internal shift-register topology clocks at 4 MHz, which sets the serial data update rate for daisy-chained multi-device panels — at 24 bits per device, a single TLC5947 updates in 6 µs, so a chain of 16 devices refreshes in under 100 µs, well within a 60 Hz frame period. The 3 V to 5.5 V supply range lets the logic interface run directly from a 3.3 V MCU or a 5 V system rail without an external level shifter.
Package and thermal path
The 32-VQFN (5x5 mm) exposed-pad package (supplier device package 32-VQFN) requires a thermal via array under the centre pad to pull heat from the die to the PCB ground plane — the -40 °C to 85 °C ambient operating range is achievable only when the pad is properly soldered to a copper island. Surface-mount assembly with the exposed pad means the reflow profile must follow the QFN solder-paste stencil aperture recommendations to avoid voiding under the die attach pad.
Regulatory and compliance
ROHS3 compliant, so it clears the EU RoHS directive without an exemption declaration — no additional paperwork for the BOM reviewer.