Diodes Incorporated MMSTA56-7

Overview

MMSTA56-7 from Diodes Incorporated is a PNP small-signal surface-mount transistor in SOT-323 package, rated for -80 V V_CEO, -500 mA I_C, 200 mW P_D, with h_FE ≥ 100 at -10 mA, and f_T = 50 MHz - used in low-power switching and amplification stages of portable audio bias networks and LED driver current sinks.

For engineers reviewing the MMSTA56-7 datasheet, MMSTA56-7 pinout, MMSTA56-7 application, or MMSTA56-7 equivalent, key selection criteria include its -80 V breakdown rating, SOT-323 thermal resistance (625 °C/W), complementary NPN pairing (MMSTA06), and RoHS-compliant green molding compound construction.

Technical Context

This PNP bipolar junction transistor operates in active or saturation mode for signal amplification and digital switching. Its epitaxial planar die ensures stable h_FE across -55°C to +150°C and supports pulsed operation up to 100 mA with V_CE(SAT) ≤ -0.25 V at I_C = -100 mA / I_B = -10 mA.

Designed for ultra-small PCB footprints, it uses alloy-42 leadframe with matte tin plating and meets J-STD-020C Level 1 moisture sensitivity. The device's f_T = 50 MHz at V_CE = -1.0 V enables audio-frequency gain control without RF instability.

Key Specifications

Pinout & Package

Package: SOT-323 - ultra-compact 3-pin surface-mount plastic case, 2.2 mm × 1.35 mm × 0.9 mm, UL 94V-0 rated, lead-free, green molding compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC807-40,215 and MMBT5401, MMSTA56-7 offers superior voltage margin over BC807 while maintaining tighter h_FE consistency than MMBT5401, all in the smaller SOT-323 footprint with verified green compliance.

Availability

MMSTA56-7 is available at Aetrix Electronics and suitable for portable audio bias networks, LED driver current sinks, low-voltage logic-level switching, and complementary pair amplifiers requiring stable component supply and RoHS-compliant manufacturing.

Supply support for MMSTA56-7 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, headquartered in Plano, Texas, serving automotive, industrial, computing, and consumer markets with high-reliability components.

The MMSTA56-7 belongs to Diodes' small-signal transistor product line, engineered specifically for space-constrained, low-power linear and switching applications in portable and battery-operated equipment.

FAQ

What is the maximum collector current for continuous operation?

The MMSTA56-7 supports -500 mA I_C continuous at T_A = 25°C on FR-4 PCB with Diodes Inc.'s recommended pad layout (AP02001). Derating applies above 25°C ambient per Fig. 1, reaching zero at ~150°C due to its 625 °C/W R_θJA.

Is MMSTA56-7 pin-compatible with MMSTA55-7?

Yes - both share identical SOT-323 package and pinout (E-B-C), but differ in voltage ratings: MMSTA55-7 has -60 V V_CEO/V_CBO, while MMSTA56-7 is rated to -80 V. Substitution is permissible only if circuit stress remains within the lower-rated device's limits.

Does MMSTA56-7 require a base current limiting resistor in switching applications?

Yes - base drive must be current-limited to avoid exceeding I_B = -10 mA (typical for saturation at I_C = -100 mA). For example, with 3.3 V GPIO driving through 1 kΩ, I_B ≈ -2.5 mA, ensuring safe and reliable saturation without overstressing the base-emitter junction.

How does the "Green" molding compound affect reliability?

The halogen-free green compound (introduced post-2006 Date Code 0627) eliminates Sb₂O₃ and brominated flame retardants while maintaining UL 94V-0 flammability rating and long-term thermal stability up to +150°C - confirmed per Diodes Inc.'s AP02001 and AP02007 documentation.