STMicroelectronics MJD45H11T4

Overview

MJD45H11T4 from STMicroelectronics is a PNP silicon power transistor in DPAK (TO-252) package, rated for 80 V V_CEO, 8 A continuous collector current, and 20 W power dissipation at T_C = 25°C; it delivers low 1 V V_CE(sat) at I_C = 8 A / I_B = 0.4 A and supports general-purpose linear amplification and hard-switching in DC-DC converters and motor drivers.

For engineers reviewing the MJD45H11T4 datasheet, MJD45H11T4 pinout, MJD45H11T4 application, or MJD45H11T4 equivalent, key selection criteria include its PNP polarity, DPAK thermal performance (R_thJC = 6.25°C/W), safe operating area under pulsed conditions, and complementary pairing with MJD44H11T4 for push-pull output stages.

Technical Context

This device uses low-voltage multi-epitaxial planar technology optimized for stable gain and low saturation voltage in linear and switching modes. Its h_FE ranges from 40 (I_C = 4 A) to 60 (I_C = 2 A) at V_CE = 1 V, and it sustains 60 V V_CEO(sus) with I_C = 30 mA and zero base drive.

The transistor operates up to 150°C junction temperature and exhibits 10 μA I_CES at V_CE = 80 V, confirming robust cutoff behavior. Its DPAK package enables direct heatsink mounting via the exposed collector tab, supporting high-current operation with controlled thermal resistance.

Key Specifications

Pinout & Package

Package: DPAK (TO-252), surface-mount, with exposed collector tab (pin 2) for thermal and electrical connection. Standard pin assignment confirmed per DS1232 Rev 5 Figure 7 and mechanical data.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD45H11T4, MJD45H11 offers identical performance in a functionally equivalent package but lacks tape-and-reel logistics optimization, while BD241C trades thermal capability and footprint compatibility for higher voltage margin in legacy through-hole designs.

Availability

MJD45H11T4 is available at Aetrix Electronics and suitable for DC-DC converter output stages, industrial relay drivers, linear audio amplifiers, and H-bridge motor driver half-bridges requiring stable component supply and consistent DPAK thermal performance.

Supply support for MJD45H11T4 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs and discrete devices for automotive, industrial, and consumer markets.

MJD45H11T4 belongs to ST's STPOWER bipolar transistor family, engineered for robustness and thermal efficiency in medium-power linear and switching applications where reliability under sustained current and temperature stress is critical.

FAQ

Is MJD45H11T4 pin-compatible with MJD44H11T4?

No - MJD45H11T4 is PNP and MJD44H11T4 is NPN, so their pinouts are complementary, not identical. Both use DPAK with Base–Collector–Emitter (B–C–E) ordering, but polarity reversal means they cannot be substituted without circuit redesign. Their shared package enables matched thermal layout in push-pull designs.

What is the maximum safe continuous collector current at 100°C case temperature?

At T_C = 100°C, derating applies: P_TOT drops to 12.5 W (from 20 W at 25°C), limiting I_C to approximately 5.6 A assuming V_CE(sat) ≈ 1 V. This value is derived from the derating curve in DS1232 Figure 2 and confirmed by R_thJC = 6.25°C/W, yielding ΔT = 75°C → P = 75 / 6.25 = 12 W.

Does MJD45H11T4 require a base resistor in switching applications?

Yes - a series base resistor is required to limit I_B to ~0.4 A for full saturation at I_C = 8 A. With typical V_BE(sat) ≈ 1.3 V and driver voltage of 5–12 V, R_B should be 9–18 Ω. Omission risks incomplete turn-on, excessive V_CE, and thermal runaway due to localized heating.

Can MJD45H11T4 be used in avalanche mode?

No - the datasheet does not specify avalanche energy rating (E_AS) or ruggedness testing. Absolute maximum V_CEO is 80 V with IB = 0 A, and sustaining voltage is rated at 60 V. Operation beyond V_CEO or unclamped inductive switching may cause irreversible breakdown; external snubbers or clamping diodes are mandatory for inductive loads.