Diodes Incorporated FZT757TC

Overview

FZT757TC from Diodes Incorporated is a 300V PNP high-voltage transistor in SOT223 package, designed for off-line switching and high-side switching applications requiring robust voltage blocking. It delivers -0.5A continuous collector current, -1A peak pulse current, and exhibits BV_CEO = -300V with V_CE(sat) = -0.5V at I_C = -100mA/I_B = -10mA, enabling efficient operation in flyback snubber circuits and industrial power supplies.

For engineers reviewing the FZT757TC datasheet, FZT757TC pinout, FZT757TC application, or FZT757TC equivalent, key selection criteria include verified high-voltage PNP capability, thermal resistance (R_θJA = 41.7°C/W on 50mm × 50mm 2oz copper), complementary pairing with FZT657, and AEC-Q101 readiness for automotive-grade reliability validation.

Technical Context

This PNP bipolar junction transistor operates with emitter-grounded configuration and supports high-voltage DC-DC conversion where negative rail control or high-side current sinking is required. Its -300V V_CEO rating and -7V V_EBO enable stable operation under transient overvoltage conditions common in AC/DC front-end stages.

The device features h_FE = 40–50 across I_C = -10mA to -100mA, f_T = 30MHz, and C_obo = 20pF at V_CB = -20V, supporting moderate-speed switching while maintaining low output capacitance for reduced turn-off losses in quasi-resonant topologies.

Key Specifications

Pinout & Package

Package: SOT223 (Type DN), surface-mount, 3-terminal molded plastic case with exposed collector tab for thermal enhancement. Weight: 0.112g. Moisture sensitivity level: J-STD-020 Level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage PNP transistor applications.

Compared with ZTX757 and MJD2955G, FZT757TC uniquely balances 300V blocking, SOT223 thermal efficiency (3W capability), and automotive-ready manufacturing-making it optimal for compact, high-reliability off-line power stages where voltage rating and package thermal performance are jointly critical.

Availability

FZT757TC is available at Aetrix Electronics and suitable for industrial power supply snubbers, AC/DC adapter auxiliary bias circuits, and high-side load switches requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for FZT757TC 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, with design, manufacturing, and sales operations across Asia, Europe, and North America.

FZT757TC belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for ruggedized power conversion in industrial, automotive, and consumer AC/DC applications demanding extended voltage range and thermal resilience.

FAQ

What is the maximum safe operating voltage for FZT757TC in continuous DC applications?

The FZT757TC is rated for V_CEO = -300V and V_CBO = -300V under DC conditions at T_A = +25°C. For reliable long-term operation, Diodes recommends limiting continuous V_CE to ≤240V to maintain ≥20% voltage margin against transients and temperature-induced degradation per JEDEC JESD78 guidelines.

Can FZT757TC replace an NPN transistor in the same circuit without redesign?

No - FZT757TC is a PNP device requiring reversed polarity biasing: base must be driven negative relative to emitter, and collector connects to the higher potential rail. Direct substitution for an NPN would invert logic polarity and likely cause circuit malfunction unless the entire drive network and power topology are reconfigured.

Is FZT757TC qualified to AEC-Q101 for automotive use?

FZT757TC is manufactured in IATF 16949 certified facilities and supports PPAP documentation. While not pre-qualified as standard, Diodes offers AEC-Q101 qualification upon request for specific lots - confirmation requires formal submission to Diodes' automotive team and completion of stress testing per Rev D requirements.

How does the SOT223 package affect thermal performance compared to TO-92 or SOT-23?

The SOT223's exposed collector tab provides significantly lower thermal resistance than TO-92 (R_θJA ≈ 200°C/W) or SOT-23 (R_θJA ≈ 250°C/W). With proper 50mm × 50mm 2oz copper, FZT757TC achieves R_θJA = 41.7°C/W - enabling 3W dissipation versus ≤0.5W for smaller packages - making it viable for medium-power linear and switching roles.