Persamaan Transistor D998 B778

Technical Report: D998 (NPN) and B778 (PNP) Transistor Pair

9. Manufacturer Datasheet Reference

For full original Sanken datasheet (in Japanese/English), search: "Sanken 2SD998 2SB778 datasheet" or download from archive sites like alldatasheet.com.

The D998 (2SD998) and B778 (2SB778) are a popular pair of complementary silicon power transistors, often found in the output stages of audio amplifiers and car audio systems. Key Specifications

These transistors are designed for high-power applications, typically recommended for 45–50W audio frequency amplifiers. 2SD998 (NPN) 2SB778 (PNP) Polarity Collector-Emitter Voltage ( VCEOcap V sub cap C cap E cap O end-sub ) Collector Current ( ICcap I sub cap C ) Power Dissipation ( PCcap P sub cap C ) 80W - 100W 80W - 100W Package Type TO-3PF / TO-3P TO-3PF / TO-3P DC Current Gain ( hFEh sub cap F cap E end-sub ) 80 – 160 80 – 160 Common Equivalents (Persamaan)

If you cannot find the exact D998/B778 pair, you can consider these substitutes, but always verify the pinout and physical package size (TO-3P/TO-3PF) before installation: Transistor D998 - Mercado Libre

Transistor 2SD998 (D998) and 2SB778 (B778) are complementary power transistors frequently used in the output stages of audio amplifiers. They are designed for high-power applications, typically in the 45–50W range. Core Specifications These transistors are almost always used as a matched pair: 2SD998 (NPN): High-power silicon transistor. 2SB778 (PNP): Complementary partner to the D998. Voltage ( VCEOcap V sub cap C cap E cap O end-sub ): 120V. Current ( ICcap I sub cap C ): 10A. Power Dissipation ( PCcap P sub cap C ): 80W to 100W, depending on the manufacturer.

Package: Typically TO-3PML or TO-3PF (large three-pin flat package). Persamaan (Equivalent Substitutes)

(full part numbers ) are a complementary pair of silicon power transistors primarily used in high-fidelity audio power amplifiers. They are designed for "push-pull" amplifier output stages, where the NPN 2SD998 handles the positive signal half-cycle and the PNP 2SB778 handles the negative half-cycle. Core Specifications These transistors are typically packaged in Persamaan Transistor D998 B778

cases, which include a metal tab for mounting to a heatsink to manage high power dissipation. Specification NPN (2SD998) / PNP (2SB778) Max Collector-Emitter Voltage ( cap V sub cap C cap E cap O end-sub Max Collector Current ( cap I sub cap C Collector Power Dissipation ( cap P sub cap C 80W - 100W DC Current Gain ( h sub cap F cap E end-sub 60 - 160 (High Linearity) Frequency ( f sub cap T Common Equivalents and Replacements

If you cannot find the original D998/B778, several equivalents offer similar or superior power handling. When replacing, it is critical to replace both (the pair) with the same model to maintain balance. 2SD718 / 2SB688

: A very common substitute for slightly lower power applications. 2SC5200 / 2SA1943

: A popular high-power alternative often found in heavier duty audio amplifiers. TIP35C / TIP36C

: Frequently used as rugged, general-purpose power equivalents. A1941 / C5198

: Another standard complementary pair often used in 50W–100W amplifier stages. Applications Audio Amplifiers Technical Report: D998 (NPN) and B778 (PNP) Transistor

: Specifically recommended for 45W–50W audio frequency output stages. Power Supplies

: Used in voltage regulator circuits due to their 120V breakdown rating. Motor Control

: Employed in DC motor driver circuits where high current (up to 10A) is required. Purchasing Information This pair is widely available from retailers such as . Prices typically range from

for a single pair, though buying in "matched lots" of 5 or 10 pairs is often more cost-effective for multi-channel amplifier repairs. or a recommendation for a specific heatsink to use with these transistors?

2.2 The PNP Transistor: 2SB778

  • Type: PNP Silicon Epitaxial Planar
  • Application: Power Amplifier, Switching
  • Collector-Base Voltage ($V_CBO$): -200 V
  • Collector-Emitter Voltage ($V_CEO$): -150 V
  • Emitter-Base Voltage ($V_EBO$): -6 V
  • Collector Current ($I_C$): -15 A
  • Power Dissipation ($P_C$): 150 W
  • DC Current Gain ($h_FE$): 40 to 100

2. Physical Packaging & Pin Configuration

Both transistors use the MT-200 (Sanyo’s large, insulated power package) or sometimes TO-3P/TO-247 variants, though the classic Sanyo MT-200 is most common.

  • Package: MT-200 (Fully encapsulated, metal-backed for heat transfer)
  • Pinout (face on, leads down):
    1. Base (B)
    2. Collector (C) – electrically connected to the metal tab/case
    3. Emitter (E)

Note: Because the case is the collector, an insulating mica washer and thermal paste are required when mounting to a common heatsink (unless using a non-conductive thermal pad). The D998 (2SD998) and B778 (2SB778) are a

Bagian 3: Daftar Lengkap Persamaan Transistor D998 B778

Berikut adalah tabel persamaan yang sudah terbukti di lapangan. Prinsipnya, D998 diganti dengan NPN, dan B778 diganti dengan PNP secara berpasangan.

A. Audio Power Amplifiers (Most common)

  • Output stage: Triple Darlington or quasi-complementary configuration.
  • Topology: Class AB with ±45V to ±65V DC rails.
  • Example: Sanyo’s own JA-Series amplifiers (e.g., JA-505, JA-885) used these as main outputs.

4. Equivalent / Substitution Data

If you are repairing a device and cannot find the original D998 or B778, you can use substitutes. When substituting, you must ensure the pinout matches.

2. Absolute Maximum Ratings (At 25°C)

Understanding the limits of these transistors is crucial for safe application and replacement.

| Parameter | Symbol | D998 (NPN) | B778 (PNP) | Unit | | :--- | :---: | :---: | :---: | :---: | | Collector-Base Voltage | $V_CBO$ | 150 | -150 | V | | Collector-Emitter Voltage | $V_CEO$ | 80 | -80 | V | | Emitter-Base Voltage | $V_EBO$ | 6 | -6 | V | | Collector Current | $I_C$ | 5 | -5 | A | | Base Current | $I_B$ | 1 | -1 | A | | Collector Power Dissipation | $P_C$ | 30 | 30 | W | | Junction Temperature | $T_j$ | 150 | 150 | °C |

Key Takeaway: These transistors can handle moderate voltage (up to 80V on the Collector-Emitter) and decent current (up to 5A), making them suitable for mid-range power output stages (approx. 20W-40W per channel).

5. Common Applications

  1. Audio Power Output Stages:
    • Used in Class-AB push-pull amplifiers. The NPN handles the positive side of the waveform, and the PNP handles the negative side.
  2. Power Supply Switching:
    • Occasionally found in the regulation circuits of older CRT televisions or linear power supplies.
  3. Motor Drivers:
    • Can be used to drive small DC motors (up to 5A) due to their decent current handling.