onsemi PZTA56

Overview

PZTA56 from onsemi is a PNP general-purpose amplifier transistor rated for −80 V V_CEO, −500 mA continuous collector current, and 1000 mW power dissipation in SOT-223-4 package; designed for linear amplification and switching in industrial control, power supply feedback, and low-frequency signal conditioning circuits.

For engineers reviewing the PZTA56 datasheet, pinout, applications, or equivalent options, key selection criteria include its −80 V breakdown rating, 100 minimum h_FE at −100 mA, −0.25 V V_CE(sat), thermal resistance of 125 °C/W, and Pb-free SOT-223-4 packaging suitable for high-current discrete gain stages.

Technical Context

The PZTA56 is a silicon PNP bipolar junction transistor optimized for general-purpose linear amplification and medium-current switching. It operates with a maximum junction temperature of +150 °C and supports DC collector currents up to −500 mA under continuous conditions.

Its electrical behavior is characterized by a minimum DC current gain (h_FE) of 100 at both −10 mA and −100 mA collector current, −1.2 V V_BE(on) at −100 mA, and a 50 MHz f_T at −100 mA, confirming suitability for audio-frequency and low-speed digital switching applications.

Key Specifications

Pinout & Package

SOT-223-4 package with exposed collector tab for enhanced thermal dissipation; standardized 4-pin layout where Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector (tab), Pin 4 = Collector (lead). The collector is internally connected across Pins 3 and 4 for improved current sharing and thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBTA56 and PN2907A, the PZTA56 provides superior thermal performance and sustained high-current gain in surface-mount form, making it optimal for production-grade industrial power and signal conditioning where reliability and power density are prioritized.

Availability

PZTA56 is available at Aetrix Electronics and suitable for industrial power supplies, motor control modules, and audio signal conditioning circuits requiring stable component supply and long-term manufacturability.

Supply support for PZTA56 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

onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT applications.

The PZTA56 belongs to onsemi's general-purpose bipolar transistor product line, engineered for robust, cost-effective amplification and switching in industrial and consumer power systems where reliability and thermal performance are essential.

FAQ

What is the maximum continuous collector current rating for the PZTA56?

The PZTA56 has a maximum continuous collector current (I_C) rating of −500 mA at T_A = 25 °C. This rating assumes proper PCB thermal design per the datasheet's FR-4 land pattern guidelines. Derating is required above 25 °C ambient, with a linear derate of 8.0 mW/°C for total device dissipation. The PZTA56 must not be operated beyond this limit without verifying junction temperature using R_JA = 125 °C/W.

Is the PZTA56 pin-compatible with the MMBTA56?

No, the PZTA56 is not pin-compatible with the MMBTA56. The PZTA56 uses a 4-pin SOT-223-4 package with dual collector terminals (Pin 3 and Pin 4), while the MMBTA56 uses a 3-pin SOT-23-3 package with single collector (Pin 1). Their pinouts, footprints, and thermal pad configurations differ fundamentally. PCB layout changes are required when substituting between these devices.

What is the typical DC current gain (h_FE) of the PZTA56 at high current?

The PZTA56 guarantees a minimum h_FE of 100 at −100 mA collector current and −1.0 V V_CE, per the datasheet's Electrical Characteristics table. This value is confirmed under standard test conditions and reflects stable gain behavior in medium-current linear operation-critical for consistent biasing in amplifier and switching circuits where predictable current transfer is required.

Does the PZTA56 support Pb-free soldering processes?

Yes, the PZTA56 is a certified Pb-free device compliant with RoHS Directive 2011/65/EU. Its marking includes the "G" suffix or microdot indicator per onsemi's generic marking diagram, and it supports standard lead-free reflow profiles (J-STD-020 Class 3). The device is qualified for peak temperatures up to 260 °C with ≤60 seconds above 217 °C, matching IPC/JEDEC standards for Pb-free assembly.

What is the thermal resistance (R_JA) of the PZTA56 under standard test conditions?

The PZTA56 has a thermal resistance R_JA of 125 °C/W when mounted on an FR-4 PCB measuring 76 mm × 114 mm × 1.57 mm with minimum land pattern size, as defined in the datasheet's Thermal Characteristics table. This value assumes no additional heatsinking; actual R_JA improves significantly with larger copper pour or external thermal vias, enabling higher usable power dissipation in well-designed layouts.