onsemi PZTA92T1

Overview

PZTA92T1 from onsemi is a PNP silicon high-voltage transistor in SOT-223 package, rated for −300 V_CEO, −50 mA I_C, and 1.5 W power dissipation at T_A = 25°C; used in high-voltage linear regulators, relay drivers, and industrial off-line switch-mode power supply (SMPS) bias supplies.

For engineers reviewing the PZTA92T1 datasheet, pinout, applications, or equivalent options, key selection criteria include verified −300 V breakdown rating, h_FE ≥ 25 at −1.0 mA I_C, V_CE(sat) ≤ −0.5 V at −20 mA I_C/−2 mA I_B, f_T ≥ 50 MHz, and SOT-223 thermal resistance of 83.3°C/W on FR-4 board.

Technical Context

This PNP bipolar junction transistor operates with emitter as input, collector as output, and base as control terminal in common-emitter configuration. It supports high-voltage switching up to −300 V with guaranteed V_(BR)CEO and V_(BR)CBO ratings, and exhibits f_T = 50 MHz for moderate-frequency amplification tasks.

Thermal performance is defined for mounting on 1.575″ × 1.575″ FR-4 PCB with 0.93 in² collector pad; R_JA = 83.3°C/W reflects this standardized layout. Cutoff currents are specified at high reverse bias: I_CBO ≤ −0.25 A at V_CB = −200 V, confirming low leakage under high-voltage blocking conditions.

Key Specifications

Pinout & Package

SOT-223 (TO-261) surface-mount package with exposed collector tab (pins 2 and 4 electrically tied), 4-pin configuration, and standardized thermal pad layout per CASE 318E-04.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD2955T4 and ZTX951, the PZTA92T1 uniquely balances −300 V capability, SMT scalability, and 1.5 W continuous dissipation without external heatsink-making it optimal for space-constrained, medium-power HV bias and driver functions.

Availability

PZTA92T1 is available at Aetrix Electronics and suitable for industrial SMPS bias supplies, high-voltage linear regulators, and relay driver circuits requiring stable component supply and long-term manufacturability.

Supply support for PZTA92T1 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 supplier focused on energy-efficient electronics, with leadership in power management, analog, sensors, and connectivity solutions.

The PZTA92T1 belongs to onsemi's high-voltage bipolar transistor product line, engineered specifically for robust, cost-effective switching and regulation in off-line power systems and industrial controls.

FAQ

What is the maximum collector-emitter voltage rating for the PZTA92T1?

The PZTA92T1 has a guaranteed minimum V_(BR)CEO of −300 V at I_C = −1.0 mA and T_A = 25°C. This rating is validated per JEDEC test conditions and applies to continuous DC operation under recommended thermal conditions. The PZTA92T1 maintains this rating across its full operating temperature range from −55°C to +150°C junction temperature, making it suitable for mains-referenced circuits where transient overvoltage margins are critical. Always verify layout thermal performance to sustain this rating in practice.

Does the PZTA92T1 have a Pb-free version, and how is it marked?

Yes, the Pb-free version is designated PZTA92T1G and carries identical electrical specifications and thermal performance as the PZTA92T1. It is marked with the same "PZTA92T1" top-side marking plus a microdot or "G" suffix depending on manufacturing lot. Both variants use the same SOT-223 package and share identical package dimensions and soldering profiles per ON Semiconductor's Soldering and Mounting Techniques Reference Manual. The PZTA92T1G complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level 1.

What is the typical DC current gain (hFE) of the PZTA92T1 at different collector currents?

The PZTA92T1 specifies h_FE minima of 25 at I_C = −1.0 mA, 40 at I_C = −10 mA, and 40 at I_C = −30 mA-all measured at V_CE = −10 V and T_A = 25°C. Gain remains stable across temperature: Figure 1 in the datasheet shows h_FE ≈ 25 at −55°C and ≈ 15 at +125°C for I_C = −10 mA. Designers should use the −55°C curve for worst-case base drive calculation in cold-environment applications. The PZTA92T1 does not guarantee h_FE above −30 mA I_C.

Can the PZTA92T1 be used in switching applications above 1 MHz?

The PZTA92T1 has an f_T of 50 MHz, indicating usable small-signal gain up to that frequency-but practical switching speed is limited by stored charge and saturation behavior. At I_C = −20 mA with I_B = −2 mA, V_CE(sat) ≤ −0.5 V and turn-off delay is dominated by minority-carrier recombination. For hard-switching above 500 kHz, consider gate-driven MOSFETs instead. The PZTA92T1 is best applied in <200 kHz switching or linear regulation where its high V_CEO and thermal efficiency outweigh speed limitations.

How is thermal performance characterized for the PZTA92T1 in real PCB layouts?

The PZTA92T1's R_JA = 83.3°C/W is measured on a standardized 1.575″ × 1.575″ FR-4 board with 0.93 in² copper area connected to pins 2 and 4 (collector). Real-world R_JA improves with larger copper pours, internal planes, or thermal vias-down to ~40°C/W with 4-layer board and 6 thermal vias under the tab. Derating curves in the datasheet show allowable power drops linearly above 25°C ambient; at 70°C ambient, max continuous P_D is ~0.9 W. Always validate thermal performance using IR imaging or thermocouple measurement on the actual PZTA92T1 application board.