Diodes Incorporated MMST5401-7-F

Overview

MMST5401-7-F from Diodes Incorporated is a PNP small-signal surface-mount transistor in SOT-323 package, rated for V_CEO = −150 V, I_C = −200 mA, and P_D = 200 mW, optimized for medium-power switching and amplification in space-constrained DC-DC converters and load-switching circuits.

For engineers reviewing the MMST5401-7-F datasheet, MMST5401-7-F pinout, MMST5401-7-F application, or MMST5401-7-F equivalent, key selection criteria include its high V_CEO rating, low V_CE(SAT) (−0.2 V at −10 mA/−1 mA), wide operating temperature range (−55°C to +150°C), and RoHS-compliant matte tin plating on Alloy 42 leadframe.

Technical Context

This PNP bipolar junction transistor uses epitaxial planar die construction for stable gain and low leakage. Its complementary NPN counterpart is MMST5551, enabling matched pair design in differential amplifiers and push-pull stages.

It operates with base-emitter forward bias control, supports DC current gain (h_FE) from 50 to 240 across I_C = −1 mA to −50 mA, and delivers f_T up to 300 MHz at V_CE = −10 V and I_C = −10 mA - suitable for audio-frequency switching and low-noise preamplifier front-ends.

Key Specifications

Pinout & Package

Package: SOT-323 - ultra-small surface-mount plastic case (2.0–2.2 mm × 1.15–1.35 mm × 0.25–0.40 mm height), UL 94V-0 rated, moisture sensitivity Level 1, 0.006 g weight.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP small-signal transistor applications.

Compared with MMBT5401-7-F and PN2907A-TP, MMST5401-7-F uniquely balances ultra-compact SOT-323 size, −150 V ruggedness, and −200 mA capability-making it optimal for miniaturized, high-reliability switching where board space and transient immunity are critical.

Availability

MMST5401-7-F is available at Aetrix Electronics and suitable for automotive lighting control, industrial sensor signal conditioning, DC-DC converter bias circuits, and power supply enable switching requiring stable component supply and consistent RoHS-compliant sourcing.

Supply support for MMST5401-7-F 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, application-optimized components for power management, signal integrity, and protection.

MMST5401-7-F belongs to Diodes' small-signal transistor product line, designed specifically for space-constrained, medium-voltage switching and amplification in automotive, industrial, and computing applications.

FAQ

What is the maximum junction temperature for MMST5401-7-F?

The absolute maximum junction temperature is +150°C, matching its storage temperature limit. Derating begins above +25°C ambient per the 625°C/W R_JA curve in Figure 1 of the datasheet; at +85°C ambient, maximum usable power drops to ~120 mW on standard FR-4 layout.

Is MMST5401-7-F pin-compatible with MMST5551?

No - MMST5401-7-F is PNP and MMST5551 is NPN; they share identical SOT-323 pinout (E-B-C), but polarity reversal means direct substitution would invert circuit function. They are complementary, not interchangeable.

Does MMST5401-7-F require a heatsink in typical operation?

No heatsink is required for ≤100 mW dissipation at ≤+70°C ambient on standard FR-4 PCB with AP02001-recommended pads. At full 200 mW, ambient must stay below +25°C or board copper area must be increased per thermal guidelines in the datasheet.

What does the "-F" suffix signify in MMST5401-7-F?

The "-F" suffix denotes Diodes Incorporated's lead-free/RoHS-compliant version, featuring matte tin plating over Alloy 42 leadframe. It replaces traditional SnPb plating while maintaining identical electrical performance and solderability per J-STD-020C Level 1 moisture sensitivity.