onsemi 2SD1684S

Overview

2SD1684S from SANYO is a PNP epitaxial planar silicon transistor designed for high-voltage switching applications, with V_CEO = −100 V, I_C = −1.5 A, P_C = 1.5 W at T_C = 25 °C, and low saturation voltage V_CE(sat) = −0.3 V at I_C = −500 mA and I_B = −50 mA. It is used in power supply switching circuits and relay drivers.

For engineers reviewing the 2SD1684S datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE classification (Q/S/T grades), TO-126ML package thermal performance, switching time (t_on = 80 ns, t_off = 1000 ns), and safe operating area under pulsed conditions.

Technical Context

This device operates as a medium-power PNP bipolar junction transistor with FBET/MBIT process technology enabling high breakdown voltage and low V_CE(sat). Its rated collector-emitter voltage is −100 V, and it supports continuous collector current up to −1.5 A with derating above T_J = 150 °C.

Electrical behavior is characterized by h_FE = 100–400 at V_CE = −5 V and I_C = −100 mA, f_T = 120 MHz at V_CE = −10 V and I_C = −50 mA, and C_ob = 11 pF at V_CB = −10 V and f = 1 MHz - parameters confirmed for the 2SD1684S variant per SANYO specification sheet No.2041–2/4.

Key Specifications

Pinout & Package

2SD1684S is housed in the TO-126ML plastic package with integral heat sink tab, compliant with JEDEC TO-126 mechanical outline and optimized for surface-mount-compatible through-hole mounting on PCBs with thermal vias.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP switching transistor applications.

Compared with 2SD1684S, 2SB1144 offers identical performance in same TO-126ML package with matching pinout and grading, while MJD2955G trades voltage headroom and compactness for higher current capacity and thermal mass - requiring PCB layout change and voltage derating.

Availability

2SD1684S is available at Aetrix Electronics and suitable for industrial power supplies, relay interface modules, and motor control subsystems requiring stable component supply and long-term obsolescence management.

Supply support for 2SD1684S 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 and discrete power devices before its acquisition by Panasonic in 2012.

The 2SD1684S belongs to SANYO's legacy high-voltage PNP transistor product line, engineered for robust switching in industrial and automotive auxiliary power systems where reliability under thermal stress was prioritized.

FAQ

What is the maximum collector-emitter voltage rating for the 2SD1684S?

The 2SD1684S has a maximum collector-emitter voltage rating (V_CEO) of −100 V at T_A = 25 °C. This rating applies under open-base conditions and decreases with rising junction temperature. Operation beyond this voltage risks avalanche breakdown and permanent device failure. The 2SD1684S datasheet specifies that voltage transients exceeding −100 V - even momentarily - must be clamped externally using snubbers or TVS diodes to ensure reliability.

Does the 2SD1684S have a built-in heat sink, and how is it thermally managed?

Yes, the 2SD1684S uses the TO-126ML package with an integral metal heat sink tab that forms part of pin 2 (collector). This tab is electrically connected to the collector and must be isolated from other conductive surfaces unless the collector node is referenced to chassis ground. Thermal resistance from junction to case (R_θJC) is not explicitly published, but the 1.5 W power rating at T_C = 25 °C implies effective heat transfer when mounted to ≥ 10 cm² copper area with thermal vias. The 2SD1684S requires no additional heatsink for ≤ 1 W continuous dissipation in still air.

How is h_FE binned for the 2SD1684S, and why does it matter in circuit design?

The 2SD1684S is binned into three h_FE groups - Q (100–200), S (200–400), and T (400 min) - per SANYO specification sheet No.2041–2/4. This binning ensures predictable base drive requirements across production lots. For example, a design targeting I_C = −1 A must supply ≥ −10 mA base current for Q-grade or ≥ −2.5 mA for T-grade. Using un-binned transistors risks marginal saturation or excessive base drive losses. The 2SD1684S ordering code includes suffixes indicating grade, enabling consistent bias network validation.

Can the 2SD1684S replace the 2SB1144 in existing designs?

Yes, the 2SD1684S and 2SB1144 share identical die, package, pinout, absolute maximum ratings, and electrical characteristics per SANYO documentation. They differ only in h_FE bin labeling and minor marking conventions - both are covered under the same specification sheet (No.2041). No PCB or schematic changes are needed when substituting 2SD1684S for 2SB1144, provided the required h_FE grade is matched. The 2SD1684S maintains full functional equivalence in all documented switching applications.

What are the typical switching times for the 2SD1684S, and how do they affect PWM operation?

The 2SD1684S exhibits t_on = 80 ns and t_off = 1000 ns under standard test conditions (I_C = −500 mA, R_B = 100 Ω, V_CC = −20 V). These values define the minimum practical PWM period: for clean square-wave switching, recommended max frequency is ≤ 500 kHz to maintain >50% duty cycle margin. At higher frequencies, incomplete turn-off causes shoot-through risk in half-bridge configurations. The 2SD1684S datasheet confirms these timings apply directly to the 2SD1684S variant without derating.