onsemi 2SA1331-4-TB-E

Overview

2SA1331-4-TB-E from SANYO is a PNP epitaxial planar silicon transistor designed for high-speed switching applications, with V_CEO = −50 V, I_C = −150 mA, h_FE rank 4 (100–200 at I_C = −1 mA), and f_T = 100 MHz at V_CE = −6 V. It operates in compact CP (SOT-323) package and is used in DC-DC converter control stages and low-power pulse generators.

For engineers reviewing the 2SA1331-4-TB-E datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE binning (rank 4), fast switching times (t_f = 160 ns), V_CE(sat) ≤ −0.8 V at I_C/I_B = 10, and CP package thermal performance up to 150 mW at T_a = 25°C.

Technical Context

This PNP transistor employs epitaxial planar construction for stable h_FE and low leakage, supporting high-speed switching with t_r = 140 ns and t_f = 160 ns under specified test conditions (V_CC = −20 V, I_C = −10 mA). Its breakdown ratings-V_CEO = −50 V, V_CBO = −60 V, and V_EBO = −5 V-enable use in medium-voltage logic-level interface and driver circuits.

The device is binned by DC current gain: h_FE = 100–200 at I_C = −1 mA, V_CE = −6 V (rank 4), and exhibits Cob = 3.5 pF at V_CB = −6 V, f = 1 MHz. Its f_T reaches 100 MHz at I_C = −1 mA, confirming suitability for sub-100 MHz signal switching.

Key Specifications

Pinout & Package

2SA1331-4-TB-E is housed in the CP (SOT-323) surface-mount package: 1.9 mm × 1.35 mm × 0.95 mm body, 0.65 mm lead pitch, gull-wing leads. Thermal resistance R_θJA ≈ 833°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2SA1331-4-TB-E, the 2SA1037AK-TP offers higher bandwidth but lacks h_FE binning, while BC807-40 delivers greater current capacity in a larger package with reduced voltage margin-making 2SA1331-4-TB-E optimal for space-constrained, medium-voltage, gain-predictable switching.

Availability

2SA1331-4-TB-E is available at Aetrix Electronics and suitable for DC-DC converter feedback, low-voltage relay drivers, and LED pulse modulators requiring stable component supply, consistent h_FE binning, and compact SOT-323 packaging.

Supply support for 2SA1331-4-TB-E 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, discrete, and power devices before its acquisition by Panasonic in 2011; its legacy product lines remain widely deployed in industrial and consumer systems.

The 2SA1331 series belongs to SANYO's high-speed PNP transistor family engineered for compact, reliable switching in power management and signal interface circuits-emphasizing gain consistency, voltage robustness, and thermal efficiency in miniature packages.

FAQ

What is the guaranteed h_FE range for 2SA1331-4-TB-E?

The 2SA1331-4-TB-E is binned to h_FE rank 4, specifying a DC current gain of 100–200 measured at I_C = −1 mA and V_CE = −6 V. This guaranteed range enables deterministic base resistor selection in saturated-switch designs without additional margin for gain variation. The "4" in the part number directly denotes this h_FE classification per SANYO's ordering system.

What is the maximum operating temperature for 2SA1331-4-TB-E?

The 2SA1331-4-TB-E has a junction temperature limit of +125°C and a storage temperature range of −55°C to +125°C. At ambient temperatures above 25°C, power dissipation must be derated linearly from 150 mW using R_θJA ≈ 833°C/W. Full-rated performance is only assured within the specified absolute maximum ratings; sustained operation near limits requires thermal analysis of the PCB layout.

Is 2SA1331-4-TB-E pin-compatible with other SOT-323 PNP transistors?

Yes, 2SA1331-4-TB-E uses the standard CP (SOT-323) package with pin 1 = Base, pin 2 = Emitter, pin 3 = Collector - matching JEDEC MO-203AA. However, electrical characteristics (e.g., V_CEO, h_FE, f_T) differ across manufacturers and families, so direct substitution requires validation of switching speed, gain, and voltage ratings in the target circuit.

What is the typical V_CE(sat) for 2SA1331-4-TB-E under standard switching conditions?

The typical V_CE(sat) for 2SA1331-4-TB-E is −0.6 V at I_C = −100 mA and I_B = −10 mA (I_C/I_B = 10), with a maximum of −0.8 V under those same conditions. This low saturation voltage reduces conduction losses in high-duty-cycle switching applications such as LED constant-current sinks or logic-level inverters.

Does 2SA1331-4-TB-E support high-frequency AC signal amplification?

No - the 2SA1331-4-TB-E is optimized for high-speed *switching*, not linear amplification. While its f_T = 100 MHz indicates potential RF utility, its datasheet specifies only switching parameters (t_r, t_f, V_CE(sat)) and DC gain; no small-signal parameters (e.g., h_fe, NF, or S-parameters) are provided. For amplification, purpose-built RF transistors with characterized gain flatness and noise figures should be selected instead of 2SA1331-4-TB-E.