Good-Ark Semiconductor MMBTA92

Overview

MMBTA92 from ON Semiconductor is a PNP bipolar junction transistor in SOT-23 package, rated for -300 V collector-base and collector-emitter breakdown voltage, -200 mA continuous collector current, and 300 mW power dissipation at 25°C ambient. It serves as a high-voltage switching or amplification device in flyback snubbers, relay drivers, and HV bias networks.

For engineers reviewing the MMBTA92 datasheet, MMBTA92 pinout, MMBTA92 application, or MMBTA92 equivalent, key selection criteria include its -300 V V_CBO/V_CEO, low V_CE(sat) of -0.25 V at I_C = -20 mA/I_B = -2 mA, f_T of 50 MHz, and SOT-23 thermal resistance of 410°C/W - critical for high-voltage discrete logic-level interfacing.

Technical Context

The MMBTA92 operates as a general-purpose PNP BJT with common-emitter configuration. Its high -300 V breakdown rating enables use in off-line auxiliary supplies and CRT deflection circuits where sustained reverse-biased collector operation is required.

DC current gain (h_FE) ranges from 60 to 200 across I_C = -1 mA to -30 mA at V_CE = -10 V, and transition frequency reaches 50 MHz at I_C = -10 mA, supporting moderate-speed switching up to ~100 kHz with controlled rise/fall times.

Key Specifications

Pinout & Package

SOT-23 surface-mount package: 3-pin, gull-wing leads, 1.3 mm height, JEDEC MO-178 compliant. Thermal pad not present; PCB copper area recommended for heat spreading.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPSA92 and MMBT2907A, the MMBTA92 uniquely balances SOT-23 miniaturization, -300 V blocking, and sufficient h_FE for robust biasing - making it optimal for space-constrained, high-voltage auxiliary supplies and snubbers where thermal mass is limited.

Availability

MMBTA92 is available at Aetrix Electronics and suitable for switch-mode power supply snubbers, high-voltage relay drivers, and CRT deflection bias networks requiring stable component supply across extended product lifecycles.

Supply support for MMBTA92 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 focused on energy-efficient electronics, delivering power management, analog, sensor, and discrete solutions for automotive, industrial, and cloud infrastructure markets.

The MMBTA92 belongs to ON Semiconductor's general-purpose bipolar transistor product line, engineered for high-voltage discrete switching and linear amplification in cost-sensitive, space-constrained power conversion and interface circuits.

FAQ

Is the MMBTA92 RoHS-compliant and halogen-free?

Yes, the MMBTA92 meets RoHS Directive 2011/65/EU and is certified halogen-free per J-STD-609. ON Semiconductor's official datasheet Rev. 2022A2 specifies "Pb-Free and Green" marking and confirms compliance with JEDEC JS709C requirements for bromine and chlorine content.

Can the MMBTA92 replace the MPSA92 in existing TO-92 designs?

No - the MMBTA92 uses SOT-23 packaging while the MPSA92 uses TO-92. Though electrically similar, their footprints, thermal paths, and mounting methods are incompatible without PCB redesign. Direct substitution is only viable in new SMT layouts.

What is the maximum safe operating area (SOA) limit at 100°C case temperature?

At T_C = 100°C, the MMBTA92's SOA is bounded by I_C ≤ 120 mA and V_CE ≤ 180 V for DC operation, derived from its 300 mW P_C rating and 410°C/W R_thJA. Pulse SOA extends further but requires duty-cycle derating per Figure 2 in the datasheet.

Does the MMBTA92 require a base resistor in switching applications?

Yes - a series base resistor is mandatory to limit I_B and prevent thermal runaway. For I_C = -20 mA with h_FE = 60, minimum I_B = 333 µA is needed; a 10 kΩ resistor from 5 V logic yields ~467 µA, ensuring saturation while avoiding excessive base drive loss.