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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Bipolar Transistor Arrays

Toshiba Semiconductor and Storage 2SC4944-Y(TE85L,F)

Name: 2SC4944-Y(TE85L,F)
Brand: Toshiba Semiconductor and Storage
SKU: 2SC4944-Y(TE85L,F)
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SC4944-Y(TE85L,F)

Manufacturer:: Toshiba Semiconductor and Storage

Category:: Bipolar Transistor Arrays

Package:: 5-TSSOP, SC-70-5, SOT-353

Datasheet:: 2SC4944-Y(TE85L,F).pdf

Description:: TRANS 2NPN 50V 150MA USV

Quantity:: RFQ Add To RFQ list

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Inventory:2,998

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Product details

Overview

2SC4944-Y(TE85L,F) from Toshiba Electronic Devices & Storage Corporation is a silicon NPN epitaxial transistor in a small dual-package configuration, designed for audio frequency general-purpose amplifier applications. It delivers V_CEO = 50 V, I_C = 150 mA (max), h_FE = 120–240 (Y-class), V_CE(sat) = 0.1 V (typ.) at I_C = 100 mA/I_B = 10 mA, and f_T = 80 MHz - enabling compact, low-distortion preamp and driver stages in consumer audio equipment.

For engineers reviewing the 2SC4944-Y(TE85L,F) datasheet, 2SC4944-Y(TE85L,F) pinout, 2SC4944-Y(TE85L,F) application, or 2SC4944-Y(TE85L,F) equivalent, key selection considerations include its Y-class h_FE binning, dual-transistor topology in 2-2L1A package, complementary pairing with 2SA1873, and FR4-mount power dissipation rating of 200 mW.

Technical Context

This dual NPN transistor uses Toshiba's PCT (Planar Collector Technology) process to achieve high voltage/current capability alongside excellent h_FE linearity (h_FE(0.1 mA)/h_FE(2 mA) = 0.95 typ.). Its design targets linear amplification in low-power analog signal chains where gain stability across bias current is critical.

The device shares common emitter-base-collector terminals per transistor (Q1/Q2), operates up to T_j = 150°C (Note 1), and is rated for V_CBO = 60 V, V_EBO = 5 V, and I_B = 30 mA - supporting robust bias network design in Class-A and AB audio stages.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	50 V - supports rail voltages up to ±24 V in single-supply or split-rail audio preamplifiers
I_C (max)	150 mA - sufficient for driving low-impedance loads (e.g., 32 Ω headphones or small speaker drivers)
h_FE range	120–240 (Y-class) - enables predictable DC biasing without individual transistor matching
f_T	80 MHz - ensures stable operation beyond audible band (20 kHz) with margin for slew-rate-limited transients
V_CE(sat)	0.1 V (typ.) at I_C=100 mA/I_B=10 mA - minimizes voltage drop and thermal rise in saturated-switch or emitter-follower configurations
C_ob	2 pF (typ.) at V_CB=10 V - limits Miller-effect capacitance in high-gain CE stages
P_C	200 mW (FR4 board, 25.4×25.4×1.6 mm) - defines thermal design envelope for PCB copper pad layout

Pinout & Package

Package: 2-2L1A - small-outline dual-transistor package (JEITA-compliant), 6.2 mg typical weight, footprint optimized for space-constrained audio modules.

Pin/Terminal	Circuit Role	Design Meaning
1 (Q1 E)	Emitter of first transistor	Common reference node for Q1; connects to ground or local emitter degeneration resistor
2 (Q1 B)	Base of first transistor	Input node for Q1; requires current-limiting base resistor or active bias network
3 (Q1 C)	Collector of first transistor	Output node for Q1; connects to load resistor, next stage input, or feedback network
4 (Q2 C)	Collector of second transistor	Output node for Q2; enables push-pull or differential pair topologies with shared collector routing
5 (Q2 B)	Base of second transistor	Input node for Q2; allows independent or mirrored bias control relative to Q1
6 (Q2 E)	Emitter of second transistor	Reference node for Q2; may be tied to Q1 E for matched emitter-coupled pairs

Key Features

Feature	Design Value
High h_FE linearity	h_FE(0.1 mA)/h_FE(2 mA) = 0.95 (typ.) - preserves gain consistency across signal amplitude variations in preamp stages
Complementary pairing	Explicitly matched to 2SA1873 (PNP) - enables balanced differential amplifiers and quasi-complementary output stages
Dual-transistor integration	Two independent NPN units in single 2-2L1A package - reduces PCB area and inter-device parameter mismatch vs. discrete singles
Low V_CE(sat)	0.1 V (typ.) - lowers quiescent power loss and improves efficiency in emitter-follower buffers

Applications

Audio Preamp Stage	Headphone Driver
Use Scenario: Low-noise voltage amplification of line-level signals (e.g., DAC output or phono preamp) before power amplification. IC Role / Device Role / Timing Role: NPN transistor configured in common-emitter topology providing 20–40 dB gain with minimal harmonic distortion. Use Value: High h_FE linearity and 80 MHz f_T ensure flat frequency response and low THD across 20 Hz–20 kHz.	Use Scenario: Direct drive of 16–32 Ω dynamic headphones from portable audio sources. IC Role / Device Role / Timing Role: Emitter-follower buffer delivering low-output-impedance current gain while preserving signal integrity. Use Value: 150 mA I_C rating and 0.1 V V_CE(sat) enable >100 mW into 32 Ω with <1% clipping at 1 kHz.
Differential Pair Amplifier	Complementary Output Stage
Use Scenario: Input stage of op-amp or discrete instrumentation amplifier requiring matched gain and offset. IC Role / Device Role / Timing Role: Dual NPN unit operating as emitter-coupled pair with shared emitter resistor and separate base inputs. Use Value: Integrated dual topology minimizes inter-transistor thermal and parametric drift versus discrete placement.	Use Scenario: Quasi-complementary output stage paired with 2SA1873 PNP transistors in Class-AB amplifier designs. IC Role / Device Role / Timing Role: NPN half of push-pull output pair handling positive half-cycle current delivery. Use Value: Complementary specification alignment with 2SA1873 ensures symmetrical slew rate and crossover distortion reduction.

Audio Preamp Stage

Headphone Driver

Use Scenario: Low-noise voltage amplification of line-level signals (e.g., DAC output or phono preamp) before power amplification.

IC Role / Device Role / Timing Role: NPN transistor configured in common-emitter topology providing 20–40 dB gain with minimal harmonic distortion.

Use Value: High h_FE linearity and 80 MHz f_T ensure flat frequency response and low THD across 20 Hz–20 kHz.

Use Scenario: Direct drive of 16–32 Ω dynamic headphones from portable audio sources.

IC Role / Device Role / Timing Role: Emitter-follower buffer delivering low-output-impedance current gain while preserving signal integrity.

Use Value: 150 mA I_C rating and 0.1 V V_CE(sat) enable >100 mW into 32 Ω with <1% clipping at 1 kHz.

Differential Pair Amplifier

Complementary Output Stage

Use Scenario: Input stage of op-amp or discrete instrumentation amplifier requiring matched gain and offset.

IC Role / Device Role / Timing Role: Dual NPN unit operating as emitter-coupled pair with shared emitter resistor and separate base inputs.

Use Value: Integrated dual topology minimizes inter-transistor thermal and parametric drift versus discrete placement.

Use Scenario: Quasi-complementary output stage paired with 2SA1873 PNP transistors in Class-AB amplifier designs.

IC Role / Device Role / Timing Role: NPN half of push-pull output pair handling positive half-cycle current delivery.

Use Value: Complementary specification alignment with 2SA1873 ensures symmetrical slew rate and crossover distortion reduction.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SC4738-Y(TE85L,F)	Same 2-2L1A package; lower f_T = 50 MHz; h_FE = 120–240 (same Y-bin); V_CEO = 50 V; I_C = 100 mA (vs. 150 mA)	Not suitable for headphone drivers >50 mW or high-slew-rate preamps above 100 kHz	Select when lower power consumption and reduced bandwidth are acceptable trade-offs for cost-sensitive designs
MMBT4401LT1G	SOT-23 single NPN; h_FE = 100–300; V_CEO = 40 V; I_C = 600 mA; no dual topology; f_T = 250 MHz	Requires two devices and additional layout area; higher f_T increases risk of RF oscillation without careful compensation	Choose for high-current switching or RF-adjacent applications where dual integration is unnecessary

Compared with 2SC4944-Y(TE85L,F), 2SC4738-Y offers identical packaging and gain binning but reduced current and bandwidth, while MMBT4401LT1G provides higher current and frequency at the cost of discrete implementation and no complementary pairing support.

Availability

2SC4944-Y(TE85L,F) is available at Aetrix Electronics and suitable for audio preamplifier stages, headphone driver circuits, differential pair amplifiers, and complementary output stages requiring stable component supply and consistent Y-class h_FE performance.

Supply support for 2SC4944-Y(TE85L,F) 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

Toshiba Electronic Devices & Storage Corporation is a Japanese semiconductor manufacturer specializing in power devices, logic ICs, and discrete components with over 30 years of analog transistor development expertise.

The 2SC4944 belongs to Toshiba's legacy audio-frequency bipolar transistor product line, engineered specifically for high-linearity, low-distortion amplification in consumer and professional audio equipment.

FAQ

What is the h_FE classification for 2SC4944-Y(TE85L,F)?

The "Y" suffix in 2SC4944-Y(TE85L,F) denotes the h_FE bin: 120–240 at V_CE = 6 V and I_C = 2 mA. This classification ensures predictable DC biasing without post-manufacture sorting. The 2SC4944-Y(TE85L,F) maintains this gain range across its specified operating temperature and voltage conditions, making it suitable for production-grade audio amplifier designs where gain consistency matters.

Is 2SC4944-Y(TE85L,F) pin-compatible with other Toshiba dual transistors?

Yes - 2SC4944-Y(TE85L,F) uses the standardized 2-2L1A package with fixed pinout (E-B-C-C-B-E). It shares mechanical and electrical pin compatibility with other Toshiba dual NPN transistors in the same footprint, including 2SC4738-Y and 2SC5001-Y. However, electrical parameters such as f_T, I_C, and V_CEO differ, so functional substitution requires verification against circuit requirements. The 2SC4944-Y(TE85L,F) remains the only Toshiba dual NPN rated for 150 mA continuous collector current in this package family.

What is the maximum power dissipation for 2SC4944-Y(TE85L,F) on a standard PCB?

The 2SC4944-Y(TE85L,F) has a total collector power dissipation (P_C) of 200 mW when mounted on a standard FR4 board (25.4 mm × 25.4 mm × 1.6 mm) with five 0.32 mm² copper pads. This rating assumes ambient temperature ≤25°C and natural convection cooling. Derating is required above 25°C at 2.0 mW/°C. The 2SC4944-Y(TE85L,F) must not exceed this limit in sustained operation to maintain junction temperature below 150°C (Note 1).

How does 2SC4944-Y(TE85L,F) support complementary amplifier design?

The 2SC4944-Y(TE85L,F) is explicitly designated as complementary to the PNP transistor 2SA1873, sharing matched V_CEO, h_FE range, and thermal characteristics. This pairing enables symmetrical Class-AB output stages with minimized crossover distortion. The 2SC4944-Y(TE85L,F) handles positive half-cycles while 2SA1873 handles negative half-cycles - a relationship confirmed in Toshiba's official documentation and widely adopted in discrete audio amplifier reference designs.

Can 2SC4944-Y(TE85L,F) be used in RF applications?

No - although the 2SC4944-Y(TE85L,F) has an f_T of 80 MHz, it is characterized and qualified exclusively for audio-frequency general-purpose amplifier applications. Its transition frequency is specified under small-signal conditions (I_C = 1 mA), and its Cob = 2 pF (typ.) and package parasitics are not optimized for RF impedance matching or stability. Toshiba's datasheet restricts usage to audio bands; using 2SC4944-Y(TE85L,F) in RF circuits may result in unpredictable gain compression or oscillation.

2SC4944-Y(TE85L,F) Specifications

Product attributes: Attribute value

Manufacturer:: Toshiba Semiconductor and Storage

Series:: -

Package/Case:: 5-TSSOP, SC-70-5, SOT-353

Packaging:: Tape & Reel (TR)

Product Status:: Active

Transistor Type:: 2 NPN (Dual) Matched Pair, Common Emitter

Current - Collector (Ic) (Max):: 150mA

Voltage - Collector Emitter Breakdown (Max):: 50V

Vce Saturation (Max) @ Ib, Ic:: 250mV @ 10mA, 100mA

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 120 @ 2mA, 6V

Power - Max:: 200mW

Frequency - Transition:: 80MHz

Operating Temperature:: 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: USV

2SC4944-Y(TE85L,F) FAQ

1.How can I place an order for 2SC4944-Y(TE85L,F) through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SC4944-Y(TE85L,F) on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for 2SC4944-Y(TE85L,F) reliable?

The price and inventory of 2SC4944-Y(TE85L,F) are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SC4944-Y(TE85L,F) is usually 5 days.

3.What payment methods are accepted for 2SC4944-Y(TE85L,F)?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SC4944-Y(TE85L,F) transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SC4944-Y(TE85L,F)?

2SC4944-Y(TE85L,F) orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SC4944-Y(TE85L,F) order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for 2SC4944-Y(TE85L,F)?

For technical support, including 2SC4944-Y(TE85L,F) datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SC4944-Y(TE85L,F) requirements.

6.How does Aetrix verify that 2SC4944-Y(TE85L,F) is sourced from the original manufacturer or authorized distributors?

All 2SC4944-Y(TE85L,F) products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 2SC4944-Y(TE85L,F) meets industry standards.

7.What is the process for return or replacement of 2SC4944-Y(TE85L,F)?

All 2SC4944-Y(TE85L,F) units undergo pre-shipment inspection (PSI). If there is an issue with 2SC4944-Y(TE85L,F), returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The 2SC4944-Y(TE85L,F) part is unused and in its original packaging.

Return procedure for 2SC4944-Y(TE85L,F):

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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