onsemi 2SC3117T

Overview

2SC3117T from SANYO is an NPN epitaxial planar silicon transistor designed for high-voltage switching applications, with V_CEO = −160 V, I_C = −1.5 A, P_C = 1 W (T_c = 25°C), f_T = 120 MHz, and h_FE ≥ 100 at I_C = −100 mA - used in color TV sound output stages and DC-DC inverters.

For engineers reviewing the 2SC3117T datasheet, pinout, applications, or equivalent options, key selection criteria include breakdown voltage margin, saturation voltage under load, thermal derating behavior, h_FE grouping consistency, and TO-126 package mechanical compatibility in high-current linear/switching amplifier designs.

Technical Context

This device operates as a medium-power NPN bipolar junction transistor optimized for switching and linear amplification in high-voltage analog and power-conversion circuits. Its MBIT process enables stable h_FE across temperature and current ranges, with guaranteed minimum h_FE of 100 at −100 mA and −5 V.

It exhibits low V_CE(sat) (≤ −0.5 V at I_C = −1 A, I_B = −100 mA), fast switching times (t_on = 0.4 µs, t_off = 1.2 µs), and robust secondary breakdown immunity - critical for flyback converter switches and audio output drivers where voltage overshoot and thermal runaway must be avoided.

Key Specifications

Pinout & Package

2SC3117T uses the TO-126 molded plastic package (SANYO standard), with lead spacing and mounting hole compatible with JEDEC TO-126 footprint. The case is electrically connected to the collector terminal.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 2SC3117T, 2SC2625 offers lower cost but sacrifices 40 V breakdown margin and 0.5 A current headroom, while MJD122G trades voltage capability for current capacity - neither provides drop-in replacement without layout or bias network revision.

Availability

2SC3117T is available at Aetrix Electronics and suitable for color TV repair, industrial inverter refurbishment, relay interface modules, and legacy audio amplifier servicing requiring stable component supply and long-term obsolescence support.

Supply support for 2SC3117T 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 portfolio emphasized ruggedness and parameter consistency.

The 2SC3117T belongs to SANYO's high-voltage NPN switching transistor family developed for consumer video equipment and industrial power conversion - prioritizing breakdown safety margin, thermal stability, and group-binned h_FE for predictable bias design.

FAQ

What is the maximum safe operating voltage for 2SC3117T in a switching application?

The 2SC3117T has an absolute maximum V_CEO rating of −160 V at T_a = 25°C. For reliable long-term operation in switching applications, SANYO recommends limiting V_CE to ≤ 80% of this value (−128 V) to accommodate voltage spikes and temperature derating. Exceeding −160 V even momentarily risks avalanche failure. Always verify actual circuit peak voltages with oscilloscope measurements before finalizing 2SC3117T usage.

Does 2SC3117T require a heatsink in continuous 1.2 A operation?

Yes - at I_C = −1.2 A and V_CE(sat) ≈ −0.45 V, power dissipation reaches ~0.54 W. With a TO-126 package thermal resistance of ~120°C/W (junction-to-ambient, no heatsink), junction temperature would exceed 150°C at 25°C ambient. A minimum 10 cm² aluminum heatsink reduces θ_JA to ~40°C/W, keeping T_j < 110°C. Derate linearly above 25°C ambient per the PC–Ta curve in the 2SC3117T datasheet.

How is h_FE binned for 2SC3117T, and why does it matter?

2SC3117T is binned into h_FE groups (R: 100–200, S: 200–400) at I_C = −100 mA and V_CE = −5 V. This binning ensures predictable DC bias points in production assemblies - eliminating need for manual gain-matching or trim pots in audio output stages or relay drivers. The "T" suffix indicates tape-and-reel packaging but does not affect h_FE grouping; always verify group code on reel label or datasheet revision.

Can 2SC3117T replace 2SC2625 in an existing design?

2SC3117T can physically replace 2SC2625 (same TO-126 package and pinout), but its higher V_CEO (−160 V vs. −120 V) and I_C (−1.5 A vs. −1.0 A) provide additional margin - making it a robust upgrade if board layout and bias resistors remain unchanged. However, h_FE spread differs (100–400 vs. 60–120), so verify quiescent current and thermal stability in linear applications before substitution.

What is the safe operating area (SOA) limitation for 2SC3117T at 100 µs pulse width?

At 100 µs pulse width and T_c = 25°C, the 2SC3117T SOA limits I_C to −2.5 A maximum when V_CE ≤ −40 V, per the ITR03075 curve. Beyond that, secondary breakdown risk increases sharply. For 100 µs pulses, avoid simultaneous high V_CE and high I_C - e.g., do not operate above −1.8 A at −100 V. Always apply SOA derating for elevated case temperatures or repetitive pulsing.