Holtek

Holtek Semiconductor is a Taiwan-based fabless maker whose parts anchor low-power consumer, metering and appliance designs. The profiles here cover two of its lines. The HT75xx-1 low-dropout regulators — the HT7533-1 fixed 3.3 V and HT7550-1 fixed 5.0 V codes in SOT-89 — pair a 30 V-tolerant input with a supply current of only a few microamps, the combination standby rails in battery meters are built around. The HT1621B is a RAM-mapping LCD driver that refreshes a 32 × 4 segment display pattern from a serial-written display memory, so a small host can drive glass without a parallel bus. Two reading habits matter with Holtek codes: the -1 suffix marks a distinct datasheet generation whose tables differ from the older HT75XX series, and clone vendors re-document several designations under extended codes — so the maker’s own selection table for the exact string is the reference an offer should be checked against.

Sourcing notes for Holtek parts. Always quote the complete manufacturer ordering code — package, temperature grade, speed or accuracy grade, and packing (reel, tube or tray) all change availability and price, and suffixes are where most mismatches happen. Check the lifecycle status on the manufacturer site before committing to a multi-year build; parts flagged not-recommended or obsolete need a last-time-buy plan or a verified alternate lined up early. With every offer, request traceability documents — date code, lot code and original packing — and confirm the inspection steps your supplier applies to high-risk lots.