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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi 2SD1191

Name: 2SD1191
Brand: onsemi
SKU: 2SD1191
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2SD1191

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: 2SD1191.pdf

Description:: TRANS NPN 60V 7A TO-220AB

Quantity:: RFQ Add To RFQ list

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Inventory:19,400

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Product details

Overview

2SD1191 from SANYO is an NPN epitaxial planar silicon Darlington transistor in TO-220AB package, rated for V_CEO = −60 V, I_C = −3.5 A (DC), P_C = 1.57 W at T_c = 25 °C, with low V_CE(sat) = −1.0 V at I_C = −3.5 A and I_B = −7 mA, used in relay drivers and printer hammer drivers.

For engineers reviewing the 2SD1191 datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed h_FE ≥ 2000 at I_C = −3.5 A, wide Active Safe Operating Area (ASO), switching time t_ON = 0.6 µs, and thermal derating to 0 W at T_c = 150 °C.

Technical Context

The 2SD1191 operates as a high-gain, medium-power NPN Darlington pair with integrated base-emitter shunt resistor network enabling direct TTL/CMOS drive. Its structure delivers high current gain (h_FE up to 10,000) while maintaining low saturation voltage under heavy load conditions.

Designed for discrete switching applications, it features a maximum collector-emitter breakdown voltage of −60 V, safe operating area validated up to I_C = 10 A (pulse), and specified switching performance with t_ON = 0.6 µs, t_OFF = 3.0 µs, and t_f = 1.7 µs under defined test conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−60 V - Maximum allowable collector-to-emitter voltage before avalanche breakdown
I_C (DC)	−3.5 A - Continuous collector current rating defining steady-state power handling capability
P_C	1.57 W at T_c = 25 °C - Thermal power dissipation limit requiring heatsink for >1 W operation
h_FE	2000–10000 at V_CE = −2 V, I_C = −3.5 A - High DC current gain enabling low-base-drive requirements
V_CE(sat)	−1.0 V max at I_C = −3.5 A, I_B = −7 mA - Low saturation voltage minimizing conduction loss in switching mode
t_ON/t_OFF	0.6 µs / 3.0 µs - Fast switching times supporting pulse-width modulation up to ~300 kHz

Pinout & Package

SANYO TO-220AB package: 3-pin through-hole, vertical mounting, metal tab electrically connected to collector, JEDEC-standard outline with 10.2 mm × 5.1 mm footprint and 18.0 mm height.

Pin/Terminal	Circuit Role	Design Meaning
1 (Base)	Control input node	Accepts low-current drive signal; internal Darlington configuration requires only ~7 mA for full turn-on
2 (Collector)	Main current output terminal	Connected to metal tab; must be isolated from heatsink unless electrically referenced to same potential
3 (Emitter)	Current return path	Common reference for load; polarity reversed vs. PNP counterpart 2SB881

Key Features

Feature	Design Value
High DC current gain	h_FE ≥ 2000 at I_C = −3.5 A enables direct logic-level drive without external pre-driver stage
Wide Active Safe Operating Area (ASO)	Validated up to I_C = 10 A (1 ms pulse) and V_CE = −40 V supports robust transient load handling
Low saturation voltage	V_CE(sat) ≤ −1.0 V at rated current reduces power loss and thermal stress in high-duty-cycle switching
Fast switching speed	t_ON = 0.6 µs and t_OFF = 3.0 µs allow efficient PWM control in motor and solenoid drivers

Applications

Printer Hammer Driver	Relay Driver
Use Scenario: Driving electromagnetic print hammers in dot-matrix printers requiring fast, high-current pulses. IC Role / Device Role / Timing Role: NPN Darlington switch delivering 3.5 A peak current per hammer coil with <1 µs turn-on for precise dot placement. Use Value: Low V_CE(sat) minimizes coil heating during rapid actuation; ASO ensures reliability across mechanical wear cycles.	Use Scenario: Controlling industrial 24 VDC relays with coil currents up to 3 A in PLC I/O modules. IC Role / Device Role / Timing Role: High-gain switching element interfacing microcontroller GPIO to relay coil, eliminating need for buffer transistors. Use Value: h_FE ≥ 2000 allows direct 5 V TTL drive; TO-220AB package provides mechanical stability in vibration-prone environments.
Voltage Regulator Control	Motor Driver Stage
Use Scenario: Pass transistor in linear voltage regulators supplying 3–5 A to analog subsystems. IC Role / Device Role / Timing Role: Series pass element operating in active region, regulated by error amplifier feedback loop. Use Value: Low V_BE(sat) and stable h_FE over temperature ensure tight output voltage regulation under varying load.	Use Scenario: Half-bridge low-side switch in brushed DC motor controllers for office automation equipment. IC Role / Device Role / Timing Role: Power stage transistor commutating motor current with PWM frequency up to 20 kHz. Use Value: Fast t_ON/t_OFF reduces switching losses; TO-220AB facilitates heatsinking for continuous 2 A operation.

Printer Hammer Driver

Relay Driver

Use Scenario: Driving electromagnetic print hammers in dot-matrix printers requiring fast, high-current pulses.

IC Role / Device Role / Timing Role: NPN Darlington switch delivering 3.5 A peak current per hammer coil with <1 µs turn-on for precise dot placement.

Use Value: Low V_CE(sat) minimizes coil heating during rapid actuation; ASO ensures reliability across mechanical wear cycles.

Use Scenario: Controlling industrial 24 VDC relays with coil currents up to 3 A in PLC I/O modules.

IC Role / Device Role / Timing Role: High-gain switching element interfacing microcontroller GPIO to relay coil, eliminating need for buffer transistors.

Use Value: h_FE ≥ 2000 allows direct 5 V TTL drive; TO-220AB package provides mechanical stability in vibration-prone environments.

Voltage Regulator Control

Motor Driver Stage

Use Scenario: Pass transistor in linear voltage regulators supplying 3–5 A to analog subsystems.

IC Role / Device Role / Timing Role: Series pass element operating in active region, regulated by error amplifier feedback loop.

Use Value: Low V_BE(sat) and stable h_FE over temperature ensure tight output voltage regulation under varying load.

Use Scenario: Half-bridge low-side switch in brushed DC motor controllers for office automation equipment.

IC Role / Device Role / Timing Role: Power stage transistor commutating motor current with PWM frequency up to 20 kHz.

Use Value: Fast t_ON/t_OFF reduces switching losses; TO-220AB facilitates heatsinking for continuous 2 A operation.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN Darlington transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
2SD1221	V_CEO = −100 V, I_C = −3 A, P_C = 1.5 W, h_FE ≥ 1000 - higher voltage rating but lower current and gain	Better suited for higher-voltage relay loads (>60 V); less optimal for high-gain, low-drive scenarios	Select when system requires >60 V blocking capability and can accept reduced h_FE and pulse current margin
BD679	V_CEO = −80 V, I_C = −4 A, P_C = 1.25 W, h_FE ≥ 750 - higher current but lower gain and power dissipation	Preferred for cost-sensitive industrial controls where gain >2000 is not required	Choose when board space permits TO-126 and design tolerates higher base drive current

Compared with 2SD1191, 2SD1221 offers superior voltage headroom but sacrifices current gain and ASO margin, while BD679 provides higher peak current but demands more base drive and has lower thermal capacity - both require layout review due to differing packages and electrical boundaries.

Availability

2SD1191 is available at Aetrix Electronics and suitable for relay drivers, printer hammer drivers, and voltage regulator control applications requiring stable component supply, long-lifecycle support, and traceable sourcing for industrial OEM programs.

Supply support for 2SD1191 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 power discrete devices, analog ICs, and optoelectronics before its acquisition by Panasonic in 2012.

The 2SD1191 belongs to SANYO's legacy high-gain Darlington transistor family designed specifically for electromechanical interface applications including solenoid, relay, and printer actuator control.

FAQ

What is the absolute maximum collector-emitter voltage rating for the 2SD1191?

The 2SD1191 has an absolute maximum V_CEO rating of −60 V at T_a = 25 °C. This value decreases with increasing junction temperature and must not be exceeded under any condition, including transient spikes. Operation above this voltage risks irreversible avalanche failure. The 2SD1191 datasheet specifies derating curves confirming safe operation down to −40 V at T_j = 125 °C.

Does the 2SD1191 have an integrated base-emitter resistor?

No, the 2SD1191 does not include an integrated base-emitter shunt resistor. It is a standard two-terminal base Darlington transistor requiring external base current limiting. Unlike "digital transistors" such as the NSD12001F, the 2SD1191 relies on external circuitry for proper biasing and turn-off control - confirmed by its pinout (Base, Collector, Emitter) and absence of R_BE in all electrical characteristics tables.

What is the guaranteed minimum DC current gain (h_FE) of the 2SD1191 at rated current?

The 2SD1191 guarantees h_FE ≥ 2000 at V_CE = −2 V and I_C = −3.5 A, with typical values reaching 10,000 under the same conditions. This high gain is intrinsic to its Darlington architecture and enables direct drive from 5 V logic outputs with minimal base current - a key specification verified in the "Electrical Characteristics" table on page 925–2/4 of the official SANYO datasheet.

Can the 2SD1191 be used as a direct replacement for the 2SB881 in circuit designs?

No, the 2SD1191 cannot serve as a direct replacement for the 2SB881 because they are complementary devices: 2SD1191 is NPN, while 2SB881 is PNP. Their pinouts are identical (TO-220AB, pin 1=Base, pin 2=Collector, pin 3=Emitter), but polarity reversal means swapping them would invert switching logic and likely cause circuit malfunction. The 2SD1191 datasheet explicitly positions it as the NPN counterpart to 2SB881, not a drop-in substitute.

What thermal derating applies to the 2SD1191 above 25 °C case temperature?

The 2SD1191's power dissipation derates linearly from 1.57 W at T_c = 25 °C to 0 W at T_c = 150 °C, yielding a thermal resistance of approximately 79.6 °C/W (calculated as (150 − 25) / 1.57). This derating curve is documented in the "PC – Tc" graph on page 925–4/4 and mandates heatsinking for sustained operation above ~0.5 W - critical for reliable use of the 2SD1191 in motor or relay driver applications.

2SD1191 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-220-3

Packaging:: Bulk

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 7 A

Voltage - Collector Emitter Breakdown (Max):: 60 V

Vce Saturation (Max) @ Ib, Ic:: 1.5V @ 7mA, 3.5A

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 2000 @ 3.5A, 2V

Power - Max:: 1.75 W

Frequency - Transition:: 20MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220AB

2SD1191 FAQ

1.How can I place an order for 2SD1191 through Aetrix?

Please submit a Request for Quotation (RFQ) for 2SD1191 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 2SD1191 reliable?

The price and inventory of 2SD1191 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2SD1191 is usually 5 days.

3.What payment methods are accepted for 2SD1191?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2SD1191 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2SD1191?

2SD1191 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2SD1191 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 2SD1191?

For technical support, including 2SD1191 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2SD1191 requirements.

6.How does Aetrix verify that 2SD1191 is sourced from the original manufacturer or authorized distributors?

All 2SD1191 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 2SD1191 meets industry standards.

7.What is the process for return or replacement of 2SD1191?

All 2SD1191 units undergo pre-shipment inspection (PSI). If there is an issue with 2SD1191, 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 2SD1191 part is unused and in its original packaging.

Return procedure for 2SD1191:

1.Submit a request within 90 days.

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

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