onsemi 2SA1249S

Overview

2SA1249S from SANYO is a PNP epitaxial planar silicon transistor designed for high-voltage switching applications, featuring V_CEO = −160 V, I_C = −1.5 A, P_C = 1 W (T_a = 25°C), h_FE ≥ 100 at I_C = −100 mA, and f_T = 120 MHz - used in color TV sound output stages and DC-DC converters.

For engineers reviewing the 2SA1249S datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed high breakdown voltage, MBIT process-enhanced ruggedness, verified saturation performance at −1.5 A, and TO-126 package thermal behavior under pulsed and DC conditions.

Technical Context

This PNP bipolar junction transistor employs SANYO's MBIT (Modified Base Injection Technology) process to achieve high V_CEO (−160 V) and stable h_FE across collector current range (−1 mA to −1.5 A), with specified V_CE(sat) ≤ −1.2 V at I_C = −1.5 A and I_B = −150 mA. Its f_T of 120 MHz supports medium-frequency switching up to ~100 kHz with low storage time (t_on = 0.4 µs, t_off = 1.2 µs).

The device operates within T_j = −55°C to +150°C and is characterized with base-emitter and collector-base reverse breakdown limits (V_EB0 = −6 V, V_CBO = −180 V), enabling robust operation in inductive load switching where voltage spikes exceed 100 V. Package thermal resistance R_θJA is 150°C/W (no heatsink), limiting continuous DC use without derating.

Key Specifications

Pinout & Package

2SA1249S is housed in a TO-126 molded plastic package (SANYO designation), with standard lead configuration: Emitter (Pin 1), Collector (Pin 2), Base (Pin 3). The collector tab is electrically connected to Pin 2 and serves as the primary thermal path.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2SA1249S, 2SA1020 offers identical package and current rating but sacrifices 10 V breakdown headroom and 40 MHz bandwidth-critical in margin-constrained CRT deflection supplies. MJD2955 trades voltage capability for current and thermal capacity, demanding layout and thermal changes that negate interchangeability.

Availability

2SA1249S is available at Aetrix Electronics and suitable for color TV repair, industrial DC-DC converter refurbishment, and relay control module production requiring stable component supply and long-lifecycle support.

Supply support for 2SA1249S 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 power discrete devices, analog ICs, and optoelectronics before its acquisition by Panasonic in 2011; known for rugged, high-reliability bipolar transistors.

The 2SA1249S belongs to SANYO's high-voltage PNP transistor family developed for consumer video equipment and industrial switching power supplies, emphasizing breakdown robustness and thermal stability in compact TO-126 packaging.

FAQ

What is the maximum safe collector-emitter voltage for 2SA1249S in continuous operation?

The absolute maximum V_CEO rating for 2SA1249S is −160 V at T_a = 25°C. Operation above this voltage risks avalanche breakdown and permanent damage. Derating is required above 25°C ambient: V_CEO decreases by 0.5 V/°C above 25°C per SANYO specification No.1060-2/3. Always maintain ≥20% margin in 2SA1249S designs handling inductive transients.

Does 2SA1249S have a built-in base-emitter resistor or protection diode?

No, 2SA1249S is a bare PNP bipolar transistor with no integrated resistors or protection diodes. External base current limiting and flyback suppression (e.g., base-emitter clamp diode) must be added per application requirements. This matches the schematic symbol and pinout shown in the official 2SA1249S datasheet (PS No.1060-3/3).

Can 2SA1249S replace 2SA1213 in an existing color TV sound output circuit?

Yes, 2SA1249S is a direct functional upgrade to 2SA1213: both are TO-126 PNP transistors with identical pinout (E-C-B), but 2SA1249S offers higher V_CEO (−160 V vs. −120 V) and improved f_T (120 MHz vs. 70 MHz). No PCB changes are needed, and it enhances reliability in aging CRT TV repair scenarios.

What is the typical h_FE range for 2SA1249S at I_C = −500 mA?

Per SANYO specification sheet No.1060-2/3, h_FE for 2SA1249S is guaranteed ≥100 at I_C = −100 mA. At I_C = −500 mA, typical h_FE is 85–120 (measured at V_CE = −5 V), decreasing gradually due to high-current beta roll-off. Designers should verify actual 2SA1249S h_FE in-circuit under load conditions.

Is 2SA1249S RoHS compliant and lead-free?

2SA1249S was manufactured prior to RoHS enforcement (pre-2006) and uses leaded solder terminations and Pb-containing die attach. It does not meet current RoHS Directive 2011/65/EU requirements. For new designs requiring compliance, consult Aetrix Electronics for qualified RoHS-compliant alternatives with equivalent electrical specs.