onsemi 2SB817D

Overview

2SB817D from SANYO Semiconductor is a PNP epitaxial planar silicon power transistor designed for high-current AF and audio output stages, featuring V_CEO = −140 V, I_C = −12 A, P_C = 60 W at T_C = 25 °C, and h_FE ≥ 60 at I_C = −1 A, used in complementary push-pull amplifier circuits with 2SD1047.

For engineers reviewing the 2SB817D datasheet, pinout, applications, or equivalent options, key selection criteria include safe operating area (ASO) under pulsed conditions, V_CE(sat) ≤ −1.6 V at I_C = −12 A, f_T ≥ 15 MHz at V_CE = −5 V, and TO-3PB mechanical compatibility with legacy TO-3 heatsink mounts.

Technical Context

The 2SB817D operates as a high-voltage, high-current PNP switching and linear amplifier device with on-chip ballast resistance enabling wide ASO and stable parallel operation. Its epitaxial planar structure ensures consistent f_T vs. I_C behavior and low V_BE(sat) across temperature.

It is specified for complementary use with the NPN 2SD1047 in Class AB audio output stages, requiring matched h_FE bins (120–200), symmetrical V_CE(sat), and identical thermal resistance profiles to minimize crossover distortion and thermal runaway risk.

Key Specifications

Pinout & Package

2SB817D uses the SANYO TO-3PB package: a 3-terminal, one-point fixing plastic molded case interchangeable with standard TO-3 mounts, with base-collector-emitter terminal layout optimized for vertical heatsink mounting and thermal symmetry.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP high-power transistor applications.

Compared with MJD47 and BD912, the 2SB817D uniquely combines −140 V rating, TO-3PB mechanical compatibility, and on-chip ballast resistance-enabling drop-in replacement in legacy TO-3 audio amplifier designs without circuit or layout modification.

Availability

2SB817D is available at Aetrix Electronics and suitable for high-fidelity audio amplifiers, industrial DC motor drives, uninterruptible power supplies, and precision linear regulator designs requiring stable component supply and long-term obsolescence management.

Supply support for 2SB817D 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 Semiconductor was a Japanese semiconductor manufacturer specializing in analog, power, and audio ICs and discrete devices before its acquisition by ON Semiconductor in 2013.

The 2SB817D belongs to SANYO's high-reliability power transistor family engineered specifically for complementary audio output stages and industrial switching applications demanding robust SOA and thermal stability.

FAQ

What is the maximum junction temperature rating for the 2SB817D?

The 2SB817D has a maximum junction temperature (T_j) of +150 °C, as specified in its Absolute Maximum Ratings table. This rating assumes proper heatsinking and derated power dissipation above case temperatures of 25 °C. Operation beyond this limit risks permanent degradation of h_FE and increased leakage current. Thermal design must maintain T_j ≤ +150 °C under worst-case ambient and load conditions to ensure reliability of the 2SB817D.

Is the 2SB817D pin-compatible with the 2SD1047 NPN transistor?

No-the 2SB817D (PNP) and 2SD1047 (NPN) share identical TO-3PB package dimensions and terminal numbering (Base=1, Collector=2, Emitter=3), but their polarity and biasing requirements are complementary, not interchangeable. While they mount identically on heatsinks and occupy the same PCB footprint, substituting one for the other without circuit redesign will cause immediate reverse-bias failure. The 2SB817D is intended for use *with*, not *instead of*, the 2SD1047 in push-pull topologies.

Does the 2SB817D require external emitter resistors for parallel operation?

No-the 2SB817D incorporates on-chip ballast resistance, explicitly stated in its datasheet features, which provides inherent current sharing between paralleled devices. This eliminates the need for discrete emitter resistors in multi-transistor output stages, reducing component count and PCB area while improving thermal coupling uniformity. External resistors are unnecessary unless specific gain-matching or fine-tuning is required beyond the factory-binned h_FE tolerance of the 2SB817D.

What is the typical f_T value of the 2SB817D at I_C = −6 A?

Per the f_T vs. I_C graph (ITR08423) in the official datasheet, the 2SB817D maintains f_T ≥ 10 MHz at I_C = −6 A and V_CE = −5 V. This performance ensures usable small-signal gain and phase margin in driver-stage applications up to mid-power levels, supporting stable feedback loop design in wideband amplifiers without additional compensation. The 2SB817D's f_T roll-off is gradual, preserving bandwidth integrity across its rated current range.

Can the 2SB817D be used in switching power supplies above 100 kHz?

The 2SB817D is not optimized for high-frequency SMPS operation above 100 kHz due to its relatively high storage time (t_s = 0.62 µs) and fall time (t_f = 0.86 µs), which increase switching losses. It is best suited for audio-frequency switching (≤20 kHz) and linear applications. For >100 kHz DC-DC converters, MOSFETs or RF-optimized BJTs with sub-100 ns switching times are preferred. The 2SB817D's design prioritizes SOA and linearity-not speed-making it inappropriate for modern high-frequency power supplies.