Diodes Incorporated MMSTA64-7-F

Overview

MMSTA64-7-F from Diodes Incorporated is a PNP epitaxial planar Darlington transistor in SOT-323 package, rated for -30 V V_CEO, -500 mA I_C, 200 mW P_D, with h_FE = 10,000–20,000 at -100 mA, used in medium-power switching and amplification circuits in space-constrained consumer and industrial controls.

For engineers reviewing the MMSTA64-7-F datasheet, MMSTA64-7-F pinout, MMSTA64-7-F application, or MMSTA64-7-F equivalent, key selection criteria include its Darlington configuration for high current gain, SOT-323 footprint compatibility, -30 V breakdown rating, -1.5 V V_CE(SAT) at -100 mA, and RoHS-compliant green molding compound.

Technical Context

This device integrates two cascaded PNP transistors in a monolithic Darlington pair, delivering high DC current gain (h_FE ≥10,000) with low base drive requirements. It operates with V_EB ≤ -10 V and supports continuous collector currents up to -500 mA under derated thermal conditions.

The SOT-323 package enables surface-mount assembly on FR-4 PCBs with AP02001-recommended pad layout. Thermal resistance R_θJA is 625 °C/W, limiting usable power dissipation to ~100 mW at 75 °C ambient per Fig. 1.

Key Specifications

Pinout & Package

Package: SOT-323 - ultra-small plastic surface-mount package (2.00–2.20 mm length × 1.15–1.35 mm width × 0.25–0.40 mm height), UL 94V-0 rated, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP Darlington transistor applications.

Compared with MMSTA63-7-F, this part offers higher guaranteed h_FE for marginal base drive scenarios; versus DMT3005LFG-7, it provides predictable bipolar switching with no gate charge delay but requires base current design.

Availability

MMSTA64-7-F is available at Aetrix Electronics and suitable for LED driver circuits, relay interfaces, thermal sensor amplifiers, and pushbutton debounce circuits requiring stable component supply and long-term manufacturability.

Supply support for MMSTA64-7-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, headquartered in Plano, Texas, serving industrial, computing, communications, and consumer markets with focus on reliability and efficiency.

The MMSTA63/MMSTA64 series belongs to Diodes' general-purpose bipolar transistor portfolio, designed specifically for space-constrained medium-power switching and amplification where high current gain and SMT compatibility are essential.

FAQ

What is the maximum safe operating temperature for MMSTA64-7-F?

The junction temperature must not exceed +150 °C, and storage temperature range is -55 to +150 °C. At 75 °C ambient, maximum power dissipation drops to ~100 mW per Fig. 1 due to R_θJA = 625 °C/W. Derating is linear above 25 °C.

Can MMSTA64-7-F replace a standard PNP transistor like BC807 in existing designs?

Yes, but only if the circuit relies on high current gain and can accommodate its Darlington-specific V_BE(SAT) ≈ -2.0 V. Base resistor values must be reduced by ~10× compared to BC807 to achieve equivalent collector current, due to doubled base-emitter junctions.

Is MMSTA64-7-F suitable for PWM-driven loads?

It supports PWM operation up to ~10 kHz with proper base drive design. Switching speed is limited by stored charge in the Darlington structure; t_on/t_off data is not specified, but f_T = 125 MHz indicates adequate bandwidth for low-frequency power control.

Does MMSTA64-7-F require a heatsink in typical applications?

No heatsink is required. With P_D = 200 mW max and R_θJA = 625 °C/W, junction-to-ambient rise is 125 °C at full power - exceeding safe limits. In practice, it operates below 100 mW in most SOT-323-mounted applications, staying within thermal safety margins.