Diodes Incorporated 2DA1971-7

Overview

2DA1971-7 from Diodes Incorporated is a PNP high-voltage switching transistor in SOT89 package, rated for -400V V_CEO, -0.5A continuous collector current, and 1.5W power dissipation. It delivers high DC current gain (h_FE ≥ 140 @ I_C = -100mA) and supports fast switching with t_s = 2165ns storage time, used in flyback converter primary-side switching and industrial HV relay drivers.

For engineers reviewing the 2DA1971-7 datasheet, 2DA1971-7 pinout, 2DA1971-7 application, or 2DA1971-7 equivalent, key selection criteria include verified -400V breakdown rating, SOT89 thermal performance (R_θJL = 10.4°C/W), pulsed switching timing (t_d/t_r/t_f), and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This PNP bipolar junction transistor operates in saturation/active regions for high-voltage DC switching, with base-emitter turn-on voltage V_BE(on) = -0.8V at I_C = -200mA and V_CE(sat) = -250mV at I_C = -100mA/I_B = -10mA. Its f_T = 75MHz enables stable operation up to mid-frequency switching.

The device uses an exposed-collector SOT89 thermal pad for low R_θJL (10.4°C/W), requiring 25mm × 25mm 1oz copper on FR4 for full 1.5W derating. Safe operating area (SOA) is defined up to -320V V_CE and -1A I_C under pulsed conditions (≤2% duty cycle).

Key Specifications

Pinout & Package

SOT89 package with exposed collector pad for thermal management; molded green compound, UL 94V-0 rated, 0.05g weight.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ZTX653 and MJD2955T4G, the 2DA1971-7 uniquely combines -400V rating, SOT89 thermal efficiency, and AEC-Q101 qualification-enabling single-device HV switching in space-constrained automotive and industrial designs without derating or auxiliary components.

Availability

2DA1971-7 is available at Aetrix Electronics and suitable for industrial flyback converters, automotive LED drivers, AC-DC auxiliary supplies, and high-voltage relay drivers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 2DA1971-7 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 centers across Asia and manufacturing in China, Taiwan, and the U.S.

The 2DA1971 belongs to Diodes' high-voltage bipolar transistor product line, engineered specifically for robust switching in industrial power conversion, automotive lighting, and appliance control systems where reliability under sustained HV stress is critical.

FAQ

What is the maximum safe operating voltage for 2DA1971-7 in continuous DC mode?

The absolute maximum V_CEO is -400V at T_A = +25°C, but derating is required above 25°C per the datasheet's thermal curve. At 100°C ambient, maximum continuous V_CE drops to approximately -320V to maintain junction temperature below 150°C with recommended PCB copper area.

Can 2DA1971-7 replace NPN transistors in existing circuits?

No-it is a PNP device with inverted polarity: emitter connects to higher potential, collector to load/ground. Direct substitution requires flipping biasing topology, reversing base drive polarity, and verifying SOA compatibility. It is not a drop-in replacement for NPN switches like MMBT2222A.

Does the SOT89 package require thermal vias for 1.5W operation?

No-thermal resistance to leads (R_θJL = 10.4°C/W) is specified with the exposed collector pad soldered to 25mm × 25mm 1oz copper on FR4, without thermal vias. Vias may improve performance but are not mandatory for rated power if the copper area and solder coverage meet spec.

Is 2DA1971-7 suitable for linear regulator applications?

Yes-its h_FE stability and low V_CE(sat) support linear pass element use, but power dissipation must stay within SOA limits. At 1A output and 5V dropout, it would dissipate 5W-exceeding its 1.5W rating. It is appropriate only for ≤300mA linear regulators with ≤5V differential.