onsemi 2SD1247T-AE

Overview

2SD1247T-AE from SANYO is a PNP epitaxial planar silicon transistor designed for large-current switching in power supplies and relay drivers, with V_CEO = −25 V, I_C = −2.5 A, V_CE(sat) = −0.4 V at I_C = −1.5 A / I_B = −75 mA, f_T = 150 MHz, and P_C = 1.0 W. It operates in industrial-grade ambient temperatures (−55°C to +150°C) and supports lamp driver and electrical equipment applications.

For engineers reviewing the 2SD1247T-AE datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, high h_FE range (100–320), low saturation voltage, wide SOA, and TO-220AB package compatibility for thermal management in high-current DC switching circuits.

Technical Context

This device uses FBET and MBIT fabrication processes to achieve stable high-current gain and low V_CE(sat) across its operating range. Its PNP configuration enables active-low control in high-side switch topologies, and its 150 MHz f_T supports moderate-speed switching up to ~100 kHz with minimal phase lag.

The transistor features a robust Safe Operating Area (SOA) rated for single-pulse currents up to 5 A (10 ms), enabling reliable surge handling in relay coil and lamp inrush scenarios. Junction temperature is rated to +150°C, supporting operation in enclosed or thermally constrained industrial enclosures without forced cooling.

Key Specifications

Pinout & Package

2SD1247T-AE is housed in a TO-220AB plastic package with insulated tab, featuring standard through-hole mounting and direct heatsink interface. Pin 1 is Emitter, Pin 2 is Collector, Pin 3 is Base - verified per SANYO PS No.1029–3/3 mechanical drawing and electrical test setup diagrams.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2SB927 and MJD2955G, the 2SD1247T-AE delivers optimal balance of current capacity, gain, and saturation voltage for 24 V industrial loads - offering lower drive complexity than MJD2955G and higher power headroom than 2SB927 without sacrificing thermal performance.

Availability

2SD1247T-AE is available at Aetrix Electronics and suitable for power supplies, relay drivers, and industrial equipment requiring stable component supply with long-term lifecycle visibility and traceable sourcing.

Supply support for 2SD1247T-AE 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 known for high-reliability discrete devices and analog ICs before its acquisition by Panasonic in 2012; its transistor product lines remain widely deployed in industrial infrastructure.

The 2SD1247T-AE belongs to SANYO's legacy high-current PNP transistor family engineered specifically for ruggedized DC switching in power conversion, electromechanical actuation, and control interface applications.

FAQ

What is the maximum continuous collector current for the 2SD1247T-AE?

The 2SD1247T-AE has a maximum continuous collector current (I_C) rating of −2.5 A at T_A = 25°C. Derating applies above 25°C ambient: approximately −15 mA/°C beyond 25°C per the PC–Ta curve in PS No.1029–3/3. At 70°C ambient, usable I_C drops to ~1.8 A with appropriate heatsinking. This rating assumes proper PCB copper area and thermal interface to maintain T_j ≤ +150°C.

Is the 2SD1247T-AE pin-compatible with the 2SB927?

Yes, the 2SD1247T-AE is pin-compatible with the 2SB927 - both use TO-220AB packages with identical pin 1 (Emitter), pin 2 (Collector), pin 3 (Base) assignments. However, the 2SD1247T-AE supports higher current (−2.5 A vs. −1.0 A) and higher f_T (150 MHz vs. 100 MHz), making it a functional upgrade where thermal and speed margins allow.

Does the 2SD1247T-AE require a heatsink in typical applications?

Yes, the 2SD1247T-AE requires a heatsink when dissipating >500 mW continuously. With P_C = 1.0 W at 25°C ambient and thermal resistance θ_JA ≈ 125°C/W (TO-220AB, 1 in² copper), junction temperature rises rapidly above 25°C. For example, at I_C = −2.0 A and V_CE(sat) = −0.4 V (0.8 W), a 10°C/W heatsink keeps T_j < 120°C at 50°C ambient - confirming necessity in most production designs.

What is the safe operating area (SOA) limit for pulsed operation of the 2SD1247T-AE?

The 2SD1247T-AE SOA supports single-pulse collector currents up to −5 A for durations of 1 ms to 100 ms, as shown in ITR08796. At 10 ms pulse width, the device safely switches loads with peak inrush >3× steady-state current - critical for driving relay coils and halogen lamps. Pulse operation must respect V_CE limits: e.g., −5 A at −10 V is within SOA, but −5 A at −20 V exceeds boundary and risks secondary breakdown.

Can the 2SD1247T-AE be used in linear regulator applications?

Yes, the 2SD1247T-AE is suitable for linear regulator pass transistor roles due to its high h_FE (100–320), low V_CE(sat), and stable SOA. In emitter-follower configurations, it delivers precise output tracking with minimal base drive overhead. However, thermal design is critical: at 2 A output and 5 V dropout, dissipation reaches 10 W - requiring substantial heatsinking and current limiting to avoid T_j exceedance.