5-channel Zener array — 24V rail protection in a small SC-88
The SMF24CT1G is a 5-channel unidirectional Zener diode array from onsemi designed for general-purpose circuit protection on a 24V rail. It clamps transients to 44V maximum at 2.5A peak pulse current (8/20µs waveform) and handles 100W peak pulse power.
onsemi lists the SMF24CT1G as Obsolete. The last-time-buy date has passed; available stock is limited to surplus and independent-distribution channels. For a BOM line that cannot spin the board, the functional alternative is a different Zener array in a similar package — expect a different pinout and layout change. Confirm the replacement's breakdown voltage and clamping spec against the 24V rail before committing.
Package and footprint — SC-88/SC70-6/SOT-363
The SMF24CT1G comes in a 6-lead SC-88 (also designated SC70-6 or SOT-363) surface-mount package. The 21pF capacitance at 1MHz per channel is low enough for most data-line protection applications — it adds minimal loading to a 24V control bus or sensor input.