Diodes Incorporated BSR33TA

Overview

BSR33TA from Diodes Incorporated is an 80V PNP medium-power transistor in SOT89 package, rated for -1A continuous collector current, with V_CE(sat) < -250mV at -150mA and BV_CEO = -80V. It serves as a high-reliability switching device in automotive load management and solenoid/relay drivers.

For engineers reviewing the BSR33TA datasheet, BSR33TA pinout, BSR33TA application, or BSR33TA equivalent, key selection criteria include its AEC-Q101 qualification, thermal resistance of 60°C/W on 50mm² copper, complementary pairing with BSR43, and low saturation voltage enabling efficient DC–DC module switching.

Technical Context

The BSR33TA is a silicon PNP bipolar junction transistor optimized for medium-power linear and switching applications. Its structure supports stable DC current gain (h_FE = 30–300 across -100µA to -500mA) and fast switching (T_on = 500ns, T_off = 650ns) under pulsed conditions with ≤2% duty cycle.

Thermally, it features an exposed collector pad with R_ΘJL = 13°C/W to lead, enabling effective heat transfer when mounted on PCB copper areas ≥15mm². Its JEDEC Class 3A HBM ESD rating (4kV) and halogen/antimony-free "Green" construction support automotive-grade robustness.

Key Specifications

Pinout & Package

Package: SOT89 - Surface-mount plastic package with exposed collector pad for thermal enhancement; dimensions per AP02002 (4.5mm × 2.45mm × 1.5mm), moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BSR43TA and MJD2955T4G, the BSR33TA uniquely balances AEC-Q101 compliance, SOT89 surface-mount compatibility, and sub-1µs switching in automotive and industrial load switching-making it optimal where space, reliability, and speed intersect.

Availability

BSR33TA is available at Aetrix Electronics and suitable for automotive load switching, industrial solenoid control, and DC–DC converter feedback requiring stable component supply and AEC-Q101 traceability.

Supply support for BSR33TA 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the US.

The BSR33TA belongs to Diodes' automotive-qualified bipolar transistor product line, engineered specifically for high-reliability load switching and actuator control in harsh-temperature environments.

FAQ

What is the maximum operating temperature for BSR33TA?

The BSR33TA has an operating junction temperature range of -65°C to +150°C, validated per AEC-Q101 stress testing. Its storage temperature matches this range, and thermal derating begins above 25°C ambient - e.g., max power drops to 1.5W at 70°C ambient with 25mm² copper.

Is BSR33TA pin-compatible with other SOT89 transistors?

BSR33TA uses standard SOT89 pinout (C-E-B left-to-right top view), matching industry convention. However, electrical parameters differ significantly from non-Diodes SOT89 PNP transistors - always verify V_CEO, h_FE, and saturation voltage before substitution.

Does BSR33TA require a base resistor in switching applications?

Yes - a series base resistor is required to limit I_B and ensure saturation. For I_C = -500mA, h_FE(min) = 30 implies minimum I_B = -16.7mA; with V_BE(sat) ≈ -1.2V and 3.3V GPIO, R_B ≈ 125Ω is typical.

Can BSR33TA replace older BSR33 variants like BSR33QTA?

BSR33TA and BSR33QTA share identical electrical and thermal specifications; the "Q" suffix denotes automotive PPAP documentation support. Both are AEC-Q101 qualified and interchangeable in circuit design, though BSR33QTA includes additional automotive traceability records.