onsemi 2SA1774

Overview

2SA1774 from onsemi is a PNP silicon general-purpose amplifier transistor in SC−75/SOT−416 package, rated for −50 V V(BR)CEO, −100 mA IC, 150 mW PD, and 140 MHz fT. It delivers high DC current gain (hFE = 120–560), low saturation voltage (VCE(sat) ≤ −0.5 V at IC = −50 mA), and operates across −55°C to +150°C junction temperature range. It is used in compact audio preamplifier stages and low-power signal switching circuits.

For engineers reviewing the 2SA1774 datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, SC−75 footprint constraints, VCE(sat) performance under −50 mA load, hFE consistency at 1 mA bias, and thermal derating behavior above 25°C ambient.

Technical Context

This device is a discrete bipolar junction transistor with fixed-emitter configuration and base-controlled current amplification. Its design emphasizes low-voltage, low-current analog amplification rather than switching speed or power handling-evidenced by fT = 140 MHz at IC = −2 mA and VCE = −12 V, and safe operating area limited to 100 mA/−50 V at single-pulse conditions.

Thermal performance is defined for FR−4 PCB mounting with minimum footprint; junction-to-ambient thermal resistance is not specified, but 150 mW power dissipation implies ~1000°C/W typical for SC−75. The −6.0 V V(BR)EBO rating confirms suitability for low-base-drive applications where emitter-base reverse stress must be constrained.

Key Specifications

Pinout & Package

2SA1774 is housed in the SC−75/SOT−416 surface-mount package (Case 463, Style 1), measuring 1.60 × 0.80 × 0.80 mm with 1.00 mm pitch. This ultra-compact outline minimizes PCB real estate in space-constrained portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC807-40 and MMBT2907A, the 2SA1774 offers optimal balance of voltage margin (−50 V), compact SC−75 footprint, and verified AEC−Q101 qualification-making it preferred for automotive-grade, space-constrained amplifier nodes where moderate current and high reliability are jointly required.

Availability

2SA1774 is available at Aetrix Electronics and suitable for audio preamplifier stages, low-power switching circuits, and sensor signal conditioning applications requiring stable component supply and long-term manufacturability.

Supply support for 2SA1774 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, delivering silicon solutions for automotive, industrial, cloud, and IoT markets.

The 2SA1774 belongs to onsemi's general-purpose bipolar transistor product line, engineered for reliable, low-cost amplification and switching in compact, thermally constrained environments.

FAQ

What is the maximum collector-emitter voltage rating for the 2SA1774?

The 2SA1774 has a maximum collector-emitter breakdown voltage V(BR)CEO of −50 V at IC = −1.0 mA. This rating defines the highest reverse voltage that can be applied between collector and emitter while keeping the transistor in active or cutoff mode without risking avalanche breakdown. Exceeding this value may cause irreversible damage. The 2SA1774 must be operated within this limit in all circuit configurations, including switching and linear amplifier applications.

Is the 2SA1774 suitable for automotive applications?

Yes, the 2SA1774 is AEC−Q101 qualified and PPAP capable, confirming its suitability for automotive applications such as body control modules, sensor interfaces, and lighting drivers. Its guaranteed operation from −55°C to +150°C junction temperature, Pb−free construction, and validated reliability testing make the 2SA1774 appropriate for under-hood and cabin-mounted electronics where thermal and environmental robustness are essential.

What package type does the 2SA1774 use, and what are its dimensions?

The 2SA1774 uses the SC−75/SOT−416 package (Case 463, Style 1), with physical dimensions of 1.60 mm × 0.80 mm × 0.80 mm and 1.00 mm lead pitch. This ultra-small outline supports high-density PCB layouts in portable and automotive electronics. Pin 1 is Base, Pin 2 is Emitter, and Pin 3 is Collector-verified in the official onsemi marking diagram and mechanical drawing.

How does the hFE range of the 2SA1774 affect circuit design?

The 2SA1774 exhibits a DC current gain (hFE) range of 120 to 560 at VCE = −6 V and IC = −1 mA. This wide spread necessitates bias network design that accommodates gain variation-typically achieved using emitter degeneration resistors or feedback loops. For stable Class-A amplifier operation, designers should verify quiescent point across the full hFE range using worst-case simulation. The 2SA1774's typical hFE of 210–460 simplifies initial prototyping but requires lot-level validation in production.

What is the transition frequency (fT) of the 2SA1774, and how is it measured?

The 2SA1774 has a typical transition frequency fT of 140 MHz, measured at VCE = −12 V, IC = −2.0 mA, and f = 30 MHz. This parameter indicates the frequency at which current gain drops to unity and reflects the device's high-frequency amplification capability. It is derived from small-signal AC analysis and assumes proper decoupling and layout practices. The 2SA1774's fT supports audio-band and low-MHz RF applications but is not intended for GHz-range operation.