Overview

The BAS21HMFHT116 from Rohm Semiconductor is a high-speed small-signal switching diode supplied in a compact surface-mount package. Devices in this class are optimized for fast switching, low junction capacitance, and low leakage, making them suitable for high-frequency and general-purpose signal routing. Typical characteristics for this type of diode include a relatively high reverse voltage rating for small-signal use, low forward current capability, and fast reverse recovery, which together support reliable operation in digital, RF, and analog front-end circuits. It is commonly used for level shifting, signal clamping, high-speed switching, and simple rectification functions in low-power circuits.

Applications

• High-speed switching and signal routing in digital logic and timing circuits
• Signal clamping, protection, and level shifting in mixed-signal designs
• RF and IF switching in communication modules and tuners
• Small-signal rectification in low-current power detection or sensing stages
• General-purpose diode functions in compact consumer and portable electronics
• Analog front-end circuits in measurement, sensor, and instrumentation boards

Alternatives & Replacement

Depending on stock availability, cost targets, or new design requirements, it may be necessary to consider alternative small-signal diodes with similar electrical and package characteristics. The suitability of a replacement will depend on parameters such as reverse voltage rating, forward current, switching speed, leakage, capacitance, and package footprint.

Recommended alternatives:

• RB520HS-30T15R – Rohm Semiconductor (Redesign Required; low compatibility score, manual review recommended)
• RB751SM-40T2R – Rohm Semiconductor (Redesign Required; package/pin compatibility not confirmed)
• MMSD4148T1 – ON Semiconductor (Redesign Required; classic small-signal switching diode)
• BAS21HE3-TP – Micro Commercial Co (Redesign Required; similar small-signal diode family)
• BAS21HT1 – ON Semiconductor (Redesign Required; same BAS21 family, check package details)

Before committing to any replacement, carefully verify pinout, package dimensions, reverse voltage and current ratings, forward voltage drop, and dynamic characteristics (reverse recovery time and capacitance). Ensure that worst-case operating conditions in your design remain within the new component’s absolute maximum ratings and that the PCB footprint matches or is updated accordingly.