onsemi MMBT4356

Overview

MMBT4356 from ON Semiconductor (formerly Fairchild) is a PNP general-purpose amplifier and switch in SOT-23 package, rated for -80 V V_CEO, -800 mA continuous I_C, and -55 °C to +150 °C operating temperature. It delivers h_FE = 50 at I_C = -10 mA and V_CE = -10 V, with V_CE(sat) = -0.15 V at I_C = -150 mA / I_B = -15 mA, used in low-voltage DC-DC bias networks and signal inversion stages.

For engineers reviewing the MMBT4356 datasheet, pinout, applications, or equivalent options, key selection considerations include its PNP polarity, SOT-23 footprint compatibility, -80 V breakdown rating, -500 mA switching capability, and thermal resistance of 357 °C/W - critical for compact power management and analog interface designs.

Technical Context

The MMBT4356 is a silicon planar epitaxial PNP transistor optimized for linear amplification and saturated switching in low-to-medium power circuits. Its h_FE spans 25–250 across I_C = -100 µA to -500 mA, and small-signal h_fe reaches 5.0 at f = 100 MHz under V_CE = -10 V / I_C = -50 mA.

It exhibits V_BE(on) = -0.9 V at I_C = -150 mA / I_B = -15 mA and NF = 3.0 dB at 1 kHz with R_S = 1 kΩ, supporting low-noise preamplifier and precision current mirror applications where base drive efficiency and thermal stability are essential.

Key Specifications

Pinout & Package

SOT-23 plastic surface-mount package with gull-wing leads; dimensions per JEDEC TO-236AB: 2.90 mm × 1.30 mm × 1.00 mm max height; marking "82" identifies MMBT4356.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP general-purpose amplifier and switch applications.

Compared with MMBT4356, PN2907A offers higher guaranteed h_FE but incompatible pinout, while MMBT2907A provides pin-for-pin compatibility with tighter gain spec but reduced voltage rating - making MMBT4356 uniquely suited for -80 V, space-constrained PNP switching where both breakdown margin and footprint are critical.

Availability

MMBT4356 is available at Aetrix Electronics and suitable for LED driver stages, DC-DC converter bias networks, and relay interface circuits requiring stable component supply and long-term industrial availability.

Supply support for MMBT4356 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

ON Semiconductor is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, communications, computing, and consumer markets.

The MMBT4356 belongs to ON Semiconductor's general-purpose bipolar transistor product line, designed for cost-sensitive, high-reliability discrete switching and amplification in compact surface-mount applications.

FAQ

What is the maximum collector-emitter voltage rating for the MMBT4356?

The MMBT4356 has a maximum collector-emitter voltage rating (V_CEO) of -80 V at T_A = 25 °C. This rating applies under DC conditions with junction temperature maintained ≤ 150 °C. Operation beyond this voltage risks irreversible device failure, and derating is required above 25 °C ambient per the thermal resistance specification of 357 °C/W.

Is the MMBT4356 pin-compatible with the MMBT2907A?

Yes, the MMBT4356 is pin-compatible with the MMBT2907A: both use SOT-23 package with identical pinout (Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector) and share the same mechanical footprint. However, MMBT4356 offers -80 V V_CEO versus -60 V for MMBT2907A, and its h_FE minimum is lower at 25 versus 100 - so functional substitution depends on voltage and gain requirements in the MMBT4356 application.

What is the typical DC current gain (h_FE) of the MMBT4356 at I_C = -10 mA?

The typical DC current gain (h_FE) of the MMBT4356 at I_C = -10 mA and V_CE = -10 V is 50, with a minimum of 25 and maximum of 250 across the production lot. This wide h_FE range reflects process variation but remains stable across temperature, supporting robust bias network design in industrial environments where MMBT4356 operates between -55 °C and +150 °C.

Can the MMBT4356 be used in switching applications up to 1 MHz?

Yes, the MMBT4356 supports switching applications up to approximately 1 MHz due to its 100 ns turn-on time and 400 ns turn-off time under V_CC = -30 V and I_C = -500 mA test conditions. Its f_T ≈ 100 MHz and low C_ob = 30 pF enable clean edge fidelity, though layout parasitics and base drive strength must be optimized to maintain performance at MMBT4356's upper frequency limit.

What is the thermal resistance (R_θJA) of the MMBT4356 in free-air conditions?

The MMBT4356 has a junction-to-ambient thermal resistance (R_θJA) of 357 °C/W under standard SOT-23 mounting conditions on FR-4 PCB with no added copper pour. This value assumes minimal pad area and natural convection; adding 100 mm² of 1 oz copper connected to the emitter pad reduces R_θJA by ~30%, directly improving safe operating area for sustained MMBT4356 power dissipation above 100 mW.