onsemi 2SD734E-AA

Overview

2SD734E-AA from SANYO is a PNP epitaxial planar silicon transistor rated for 1 W continuous collector dissipation, −50 V V_CEO, −1.5 A I_C, with DC current gain (h_FE) of 60–120 at −100 mA and −2 V, optimized for audio frequency output stages, electronic governors, and DC-DC converter switching applications.

For engineers reviewing the 2SD734E-AA datasheet, pinout, applications, or equivalent options, key selection criteria include its −50 V V_CEO, −1.5 A I_C pulsed rating, low V_CE(sat) of −0.5 V at −1 A/−100 mA, f_T ≥ 25 MHz, and TO-92 (SC-43) package compatibility with legacy through-hole power amplifier designs.

Technical Context

The 2SD734E-AA operates as a medium-power PNP bipolar junction transistor with epitaxial base construction, enabling stable h_FE across −50 mA to −500 mA collector current range and reliable saturation performance in linear and switching modes. Its −50 V V_CEO and −20 V V_CB0 support operation in mid-voltage DC-DC feedback loops and audio driver rails up to ±24 V.

Thermal design is constrained by a 150 °C maximum junction temperature and 600 mW derated power at 25 °C ambient, requiring heatsinking above 50 °C ambient. The device exhibits f_T = 25 MHz at −100 mA/−10 V, confirming suitability for AF and low-frequency SMPS control-not RF or high-speed digital switching.

Key Specifications

Pinout & Package

2SD734E-AA is housed in a TO-92 (SC-43) plastic package with 3 leads, standardized for through-hole mounting and manual prototyping. Pin identification follows JEDEC TO-92 orientation: viewed from flat side with leads down, left-to-right is Emitter (1), Collector (2), Base (3).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2SB698 and BC557B, the 2SD734E-AA provides balanced trade-offs: sufficient h_FE for predictable base drive, −50 V rating for robustness in industrial supplies, and 1 W dissipation for real-world audio/governor loads-making it the default choice where both gain stability and power capability are required.

Availability

2SD734E-AA is available at Aetrix Electronics and suitable for audio power amplifiers, electronic governors, and DC-DC converter error amplifiers requiring stable component supply, long-term obsolescence management, and traceable sourcing for industrial control systems.

Supply support for 2SD734E-AA 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

SANYO Electric Co., Ltd. was a Japanese semiconductor manufacturer specializing in analog and power discrete devices, known for reliability in consumer, industrial, and automotive electronics before its acquisition by Panasonic in 2012.

The 2SD734E-AA belongs to SANYO's legacy general-purpose PNP transistor product line, designed specifically for cost-sensitive, medium-power linear and switching applications in audio, power regulation, and motor control systems.

FAQ

What is the maximum continuous collector current rating for the 2SD734E-AA?

The 2SD734E-AA has a maximum continuous collector current (I_C) rating of −700 mA at T_A = 25 °C. This value decreases linearly with rising ambient temperature, reaching zero at 150 °C junction temperature. For sustained operation above 50 °C ambient, PCB copper pour or external heatsinking is required to maintain safe junction temperature. The 2SD734E-AA also supports −1.5 A pulsed current for short durations, useful in motor startup or transient load conditions.

Is the 2SD734E-AA pin-compatible with the 2SB698?

Yes, the 2SD734E-AA is pin-compatible with the 2SB698 in the TO-92 (SC-43) package, sharing identical pinout: Emitter (1), Collector (2), Base (3) when viewed from the flat side with leads downward. Both devices share identical absolute maximum ratings and thermal specifications. However, their h_FE bins differ-2SD734E-AA is rated 60–120 while 2SB698 is 120–240-so circuit gain stability must be verified if substituting.

Can the 2SD734E-AA be used in a Class-A audio amplifier output stage?

Yes, the 2SD734E-AA is explicitly characterized for 1 W AF output applications and supports Class-A operation with proper biasing. At V_CE = −12 V and I_C = −80 mA, it delivers low-distortion 1 W into 8 Ω loads. Its −0.5 V V_CE(sat) and stable h_FE across temperature ensure consistent quiescent current and thermal behavior. The 2SD734E-AA's TO-92 package requires adequate PCB copper area to dissipate ~600 mW under continuous Class-A conditions.

What is the typical f_T of the 2SD734E-AA and how does it affect switching use?

The 2SD734E-AA has a minimum f_T of 25 MHz at I_C = −100 mA and V_CE = −10 V. This bandwidth supports reliable operation in DC-DC converter error amplifiers and low-frequency switching applications up to ~100 kHz. It is not suitable for MHz-range switching or RF circuits. In switching use, the 2SD734E-AA achieves turn-on/turn-off times consistent with its f_T, enabling clean square-wave response in electronic governor PWM stages without excessive ringing.

Does the 2SD734E-AA require a heatsink in a 1 W audio amplifier application?

In a 1 W continuous audio amplifier output stage, the 2SD734E-AA dissipates approximately 600 mW at typical Class-A/B bias points. Its TO-92 package has a junction-to-ambient thermal resistance (R_θJA) of ~200 °C/W. Without heatsinking, this results in ~120 °C junction rise above ambient-exceeding the 150 °C maximum. Therefore, a minimum 1 cm² copper pad (2 oz Cu) is recommended; for ambient >50 °C or continuous duty, a clip-on aluminum heatsink is advised to keep the 2SD734E-AA within safe thermal limits.