onsemi 2SA1248S

Overview

2SA1248S from SANYO is a PNP epitaxial planar silicon transistor designed for high-voltage switching applications, featuring V_CEO = –160 V, I_C = –700 mA, P_C = 1 W at T_C = 25 °C, h_FE = 100–200 at I_C = –100 mA, and f_T = 110 MHz - used in color TV sound output stages and DC-DC converter switching circuits.

For engineers reviewing the 2SA1248S datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, TO-126 package mapping, terminal roles, real-world use cases in audio and power conversion, and two validated alternative transistors with documented differences in gain grouping and saturation voltage.

Technical Context

This PNP bipolar junction transistor employs SANYO's MBIT process to achieve high breakdown voltage and stable current handling under pulsed switching conditions. Its design supports common-emitter configurations with fixed-base drive, where V_CE(sat) ≤ –0.5 V at I_C = –300 mA and I_B = –30 mA ensures low conduction loss in medium-power switching.

The device operates within a junction temperature range of –55 °C to +150 °C and exhibits Cob = 11 pF at V_CB = –10 V (f = 1 MHz), supporting stable high-frequency switching up to 110 MHz in tuned or pulse-width modulated circuits.

Key Specifications

Pinout & Package

SANYO TO-126 plastic package (3-lead, vertical mounting, metal tab connected to collector). Dimensions: 15.5 mm × 10.0 mm × 4.8 mm (L × W × H); tab electrically tied to Pin 2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2SA1248S, 2SA1020 offers lower cost but sacrifices 10 V breakdown margin and 30 MHz bandwidth, while BCP53-16 trades through-hole robustness and voltage headroom for SMT compatibility and tighter h_FE spread - neither is pin-compatible, and both require layout revision.

Availability

2SA1248S is available at Aetrix Electronics and suitable for color TV repair, industrial DC-DC converter refurbishment, and fluorescent ballast replacement requiring stable component supply and long-lifecycle support.

Supply support for 2SA1248S 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 before its acquisition by Panasonic in 2012.

The 2SA1248S belongs to SANYO's legacy high-voltage PNP transistor family engineered for reliability in consumer audio and power conversion systems - emphasizing ruggedness, consistent gain, and thermal stability under pulsed loads.

FAQ

What is the maximum collector-emitter voltage rating for the 2SA1248S?

The 2SA1248S has a maximum collector-emitter voltage rating (V_CEO) of –160 V at T_A = 25 °C. This rating applies with the base open and defines the upper limit for safe blocking operation in switching circuits. Exceeding this voltage, even momentarily, risks avalanche breakdown and permanent device failure. The 2SA1248S datasheet specifies this value under absolute maximum ratings and confirms it across all h_FE variants (100–200 groupings).

Is the 2SA1248S pin-compatible with the 2SC3116?

No - the 2SA1248S (PNP) and 2SC3116 (NPN) are complementary devices sharing the same TO-126 package and pinout (Emitter–Collector–Base), but they are not functionally interchangeable. While both use identical mechanical layout (Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base), their polarity, biasing requirements, and circuit roles differ fundamentally. The 2SA1248S must be used in PNP-configured circuits; substituting it for 2SC3116 will prevent proper operation.

What is the typical DC current gain (h_FE) of the 2SA1248S at 100 mA collector current?

The 2SA1248S is binned into three h_FE groups per the official SANYO specification: 100–200, 140–280, and 200–400. At I_C = –100 mA and V_CE = –5 V, the standard-grade 2SA1248S (ordering number ENN1032B) exhibits h_FE = 100–200. This range ensures predictable base drive requirements in switching designs - for example, achieving saturation at I_C = –300 mA typically needs I_B ≈ –30 mA.

Does the 2SA1248S have a built-in base-emitter resistor?

No, the 2SA1248S is a standard discrete PNP bipolar transistor without any integrated resistors. It features three external terminals only (Emitter, Collector, Base) and requires external base biasing circuitry - such as a series resistor from a negative control voltage - to operate correctly. Unlike digital transistors (e.g., DTA/DTB series), the 2SA1248S does not incorporate internal base-resistor networks.

What is the thermal resistance from junction to case (R_θJC) for the 2SA1248S?

The 2SA1248S has a junction-to-case thermal resistance (R_θJC) of 5 °C/W, derived from its 1 W power dissipation rating at T_C = 25 °C and maximum junction temperature of +150 °C. This value assumes direct metal-tab contact with an ideal heatsink. In practice, R_θJA rises significantly without heatsinking - e.g., to ~120 °C/W in free-air conditions - making thermal interface design essential for sustained operation above 300 mA.