onsemi 2SB1131T

Overview

2SB1131T from SANYO is a PNP epitaxial planar silicon transistor designed for high-current switching in strobe circuits, relay drivers, and lamp drivers. It delivers −5 A continuous collector current, −20 V collector–emitter breakdown voltage (V_CEO), −25 V collector–base voltage (V_CBO), 1 W power dissipation at T_a = 25°C, and features low saturation voltages of −0.5 V (V_CE(sat)) and −1.0 V (V_BE(sat)) at I_C = −3 A, I_B = −60 mA.

For engineers reviewing the 2SB1131T datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, TO-220AB package with emitter-collector-base terminal order, −5 A DC current capability, fast switching times (t_on = 40 ns, t_off = 200 ns), and suitability for pulsed high-power loads in industrial lighting and flash systems.

Technical Context

The 2SB1131T operates as a medium-power PNP bipolar junction transistor optimized for saturated switching rather than linear amplification. Its FBET/MBIT process enables low V_CE(sat) and high h_FE (100–400 at I_C = −500 mA, V_CE = −2 V), supporting robust base drive efficiency in discrete switch topologies.

It exhibits a gain-bandwidth product f_T of 30 MHz at I_C = −200 mA, V_CE = −5 V, confirming usable frequency response for kHz-range switching applications. Thermal design must account for its 150°C maximum junction temperature and 1.45°C/W junction-to-case thermal resistance in TO-220AB mounting.

Key Specifications

Pinout & Package

2SB1131T is housed in a TO-220AB plastic package with integral metal tab (electrically connected to collector), standardized for through-hole mounting and heatsinking. Pin identification is viewed from the front (flat side) with leads down: Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MJD2955G and 2SA1943, the 2SB1131T offers the optimal balance of TO-220AB mechanical compatibility, −20 V blocking, −5 A current, and −0.5 V V_CE(sat) for cost-sensitive, medium-voltage, high-pulse-current industrial switching-without over-spec'ing voltage or sacrificing thermal efficiency.

Availability

2SB1131T is available at Aetrix Electronics and suitable for strobe flash systems, DC relay driver modules, and lamp dimming circuits requiring stable component supply, long-term obsolescence management, and traceable sourcing for industrial OEM programs.

Supply support for 2SB1131T 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 2012; its transistor portfolio emphasized reliability and manufacturability for industrial applications.

The 2SB1131T belongs to SANYO's legacy high-current PNP transistor family engineered specifically for pulsed power switching in photographic strobes, industrial controls, and DC load drivers-prioritizing saturation efficiency, ruggedness, and TO-220 compatibility.

FAQ

What is the maximum continuous collector current rating for the 2SB1131T?

The 2SB1131T has a maximum continuous collector current (I_C) rating of −5 A at T_a = 25°C with adequate heatsinking. Derating is required above 25°C ambient per its thermal resistance profile; at 75°C ambient, the usable I_C drops to approximately −3.2 A to maintain T_j ≤ 150°C. This rating is validated under DC or low-duty-cycle pulsed conditions as specified in the original SANYO datasheet No.2420.

Is the 2SB1131T pin-compatible with other TO-220 PNP transistors like the 2N2907?

No, the 2SB1131T is not pin-compatible with the 2N2907. While both use TO-220 packages, the 2SB1131T pinout is Emitter (1), Collector (2), Base (3) when viewed from the front with leads down, whereas the 2N2907 uses Emitter (1), Base (2), Collector (3). Swapping them without verifying pin assignment risks circuit failure. Always confirm pinout using the official 2SB1131T datasheet before PCB layout or replacement.

Does the 2SB1131T support switching at frequencies above 100 kHz?

The 2SB1131T can operate reliably up to ~500 kHz in pulsed switching applications, supported by its 30 MHz f_T and measured t_on/t_off of 40 ns/200 ns. However, practical frequency limits depend on load, drive strength, and thermal management; at 100 kHz with 50% duty cycle and I_C = −3 A, junction temperature must be monitored to avoid exceeding 150°C. It is not intended for RF or MHz-class switching.

What is the typical h_FE range for the 2SB1131T at −500 mA collector current?

The 2SB1131T is binned for h_FE = 100–400 at I_C = −500 mA and V_CE = −2 V, per the "Continued on next page" h_FE classification table in the official datasheet. Units marked "A" (200–400), "B" (100–200), or "C" (40–100) exist, but the standard 2SB1131T grade corresponds to the 100–400 bin. Designers should use h_FE(min) = 100 for worst-case base drive calculations.

Can the 2SB1131T be used in linear regulator applications?

Yes, the 2SB1131T can be used in linear regulator configurations-such as emitter-follower pass elements-due to its high h_FE, low V_CE(sat), and 1 W power rating. However, it is not optimized for low-noise or precision reference applications. For stable operation, ensure junction temperature remains below 150°C under worst-case dropout and load conditions, and include adequate base current limiting to prevent thermal runaway.