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

onsemi KSH122TF

Name: KSH122TF
Brand: onsemi
SKU: KSH122TF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: KSH122TF

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: KSH122TF.pdf

Description:: TRANS NPN DARL 100V 8A DPAK

Quantity:: RFQ Add To RFQ list

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Inventory:6,360

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Product details

Overview

KSH122TF from ON Semiconductor is an NPN silicon Darlington transistor in TO-252 (DPAK) package, rated for 100 V V_CEO, 8 A DC collector current, and 20 W power dissipation at T_C = 25°C, with built-in emitter-collector damper diode and h_FE ≥ 1000 at I_C = 4 A - used as a high-gain switching device in DC-DC converter output stages.

For engineers reviewing the KSH122TF datasheet, pinout, applications, or equivalent options, key selection criteria include its Darlington configuration with integrated damper diode, DPAK thermal performance, V_CE(sat) ≤ 4 V at 8 A/80 mA drive, and compatibility with surface-mount power regulator layouts requiring robust I_C handling and low base drive burden.

Technical Context

The KSH122TF implements a two-stage NPN Darlington structure with internal base-emitter resistors (R1 ≈ 8 kΩ, R2 ≈ 0.12 kΩ), enabling high DC current gain while reducing external bias complexity. Its integrated emitter-to-collector damper diode suppresses inductive kickback without discrete clamping components.

It operates in linear or saturated switching mode with V_BE(on) = 2.8 V at I_C = 4 A and exhibits safe operating area (SOA) compliance up to 100 V × 8 A under pulsed conditions (t_p ≤ 300 μs, duty ≤ 2%), supporting reliable use in flyback and forward converter primary-side switches.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	100 V - Maximum sustainable collector-emitter voltage before breakdown; defines upper limit for switch voltage rating in DC-DC topologies.
I_C (DC)	8 A - Continuous collector current capability; supports medium-power switching loads without forced cooling at T_C ≤ 25°C.
h_FE	1000–12000 - High DC current gain enables low base drive current (e.g., 8 mA drives 8 A), reducing driver stage complexity.
V_CE(sat)	4 V @ I_C = 8 A, I_B = 80 mA - Saturation voltage directly impacts conduction loss and thermal rise in high-current switching.
P_C	20.0 W @ T_C = 25°C - Thermal power limit at case temperature; derates linearly above 25°C per Figure 7.
C_ob	200 pF @ V_CB = 10 V - Output capacitance affects switching speed and EMI in hard-switched converters.

Pinout & Package

Package: TO-252-3L (DPAK), surface-mount, lead-formed for PCB mounting; thermally enhanced plastic package with exposed drain pad (pin 2) for heatsinking.

Pin/Terminal	Circuit Role	Design Meaning
1 (Base)	Control input node	Receives base current to initiate and sustain Darlington conduction; requires current-limiting resistor in series with driver.
2 (Collector)	High-current output node	Connected to load or inductive energy storage element; electrically tied to exposed metal tab for thermal path.
3 (Emitter)	Power return node	Serves as common reference for load current; internally connected to damper diode cathode.

Key Features

Feature	Design Value
Built-in emitter-collector damper diode	Eliminates need for external flyback diode in inductive switching applications like relay drivers or motor control.
DPAK surface-mount package	Enables automated assembly and provides superior thermal resistance (R_θJC ≈ 1.5°C/W) vs. through-hole alternatives.
h_FE ≥ 1000 at I_C = 4 A	Reduces required base drive current by >10× compared to single NPN transistors, easing microcontroller GPIO or logic-level driver interface.
V_CEO = V_CB0 = 100 V	Supports operation across 48 V industrial bus systems and 100 V peak flyback voltages without derating.

Applications

Switching Regulators	DC-DC Converters
Use Scenario: Primary-side switch in non-isolated buck regulators delivering up to 60 W. IC Role / Device Role / Timing Role: Power switching transistor controlling energy transfer into output inductor. Use Value: High h_FE reduces gate-driver IC or MCU pin loading; integrated damper diode simplifies layout and improves reliability under inductive stress.	Use Scenario: High-side switch in forward or flyback converter output stage driving 12 V/5 A loads. IC Role / Device Role / Timing Role: Main power switch modulating transformer primary current during PWM on-time. Use Value: 100 V V_CEO accommodates reflected voltage spikes; 8 A I_C rating supports continuous conduction mode operation.
Power Amplifiers	Industrial Motor Drivers
Use Scenario: Class AB output stage in audio amplifiers delivering 20 W into 8 Ω loads. IC Role / Device Role / Timing Role: Linear power gain element biased in active region for analog signal reproduction. Use Value: Low V_BE(on) = 2.8 V ensures stable quiescent current setting; SOA curve supports safe operation under dynamic load transients.	Use Scenario: Solenoid or small DC motor driver in PLC I/O modules. IC Role / Device Role / Timing Role: High-current digital switch turning on/off inductive actuator coils. Use Value: Integrated damper diode prevents voltage overshoot exceeding 100 V during coil de-energization, eliminating external snubbers.

Switching Regulators

DC-DC Converters

Use Scenario: Primary-side switch in non-isolated buck regulators delivering up to 60 W.

IC Role / Device Role / Timing Role: Power switching transistor controlling energy transfer into output inductor.

Use Value: High h_FE reduces gate-driver IC or MCU pin loading; integrated damper diode simplifies layout and improves reliability under inductive stress.

Use Scenario: High-side switch in forward or flyback converter output stage driving 12 V/5 A loads.

IC Role / Device Role / Timing Role: Main power switch modulating transformer primary current during PWM on-time.

Use Value: 100 V V_CEO accommodates reflected voltage spikes; 8 A I_C rating supports continuous conduction mode operation.

Power Amplifiers

Industrial Motor Drivers

Use Scenario: Class AB output stage in audio amplifiers delivering 20 W into 8 Ω loads.

IC Role / Device Role / Timing Role: Linear power gain element biased in active region for analog signal reproduction.

Use Value: Low V_BE(on) = 2.8 V ensures stable quiescent current setting; SOA curve supports safe operation under dynamic load transients.

Use Scenario: Solenoid or small DC motor driver in PLC I/O modules.

IC Role / Device Role / Timing Role: High-current digital switch turning on/off inductive actuator coils.

Use Value: Integrated damper diode prevents voltage overshoot exceeding 100 V during coil de-energization, eliminating external snubbers.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TIP122G	Same pinout (TO-220), higher R_θJA (65°C/W vs. DPAK's ~60°C/W), no integrated damper diode.	Requires external flyback diode; less suitable for space-constrained SMT designs.	Select when through-hole mounting and discrete clamping are acceptable.
MJD122G	TO-252 package like KSH122TF but lower V_CEO = 60 V and h_FE = 1000–4000 (min–max).	Limited to ≤ 48 V bus systems; reduced gain margin at high I_C.	Select when cost sensitivity outweighs 100 V headroom and ultra-high gain requirements.

Compared with TIP122G and MJD122G, the KSH122TF uniquely combines DPAK surface-mount compatibility, integrated damper diode, and guaranteed h_FE ≥ 1000 at 8 A - making it optimal for compact, high-reliability 100 V switching applications where base drive efficiency and layout simplicity are critical.

Availability

KSH122TF is available at Aetrix Electronics and suitable for switching regulators, DC-DC converters, and industrial motor drivers requiring stable component supply, consistent parametric performance, and long-term manufacturability assurance.

Supply support for KSH122TF 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

ON Semiconductor is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, and cloud power applications.

The KSH122TF belongs to ON Semiconductor's general-purpose power transistor product line, designed specifically for high-gain, medium-power switching in surface-mount power conversion and control circuits.

FAQ

What is the pin configuration of the KSH122TF?

The KSH122TF uses a standard TO-252-3L (DPAK) pinout: Pin 1 is Base, Pin 2 is Collector (connected to exposed metal tab), and Pin 3 is Emitter. This matches JEDEC MO-238 and is verified in ON Semiconductor's KSH122/D datasheet Rev. 3. The KSH122TF pinout supports direct PCB thermal coupling via the collector tab and eliminates ambiguity in automated placement.

Does the KSH122TF include a built-in damper diode?

Yes, the KSH122TF integrates a damper diode between emitter and collector, as confirmed in the "Features" section and Equivalent Circuit diagram of the official datasheet. This diode protects against inductive voltage spikes during turn-off, allowing the KSH122TF to operate safely in relay, solenoid, and transformer-driven circuits without external clamping components.

What is the maximum continuous collector current for the KSH122TF?

The KSH122TF is rated for 8 A DC collector current (I_C) at case temperature T_C = 25°C, per Absolute Maximum Ratings table in the ON Semiconductor datasheet. At elevated temperatures, current must be derated linearly - e.g., ~5.5 A at T_C = 100°C - using the 20 W P_C rating and thermal resistance data.

How does the KSH122TF compare to the TIP122 in terms of package and drive requirements?

The KSH122TF uses a surface-mount TO-252 (DPAK) package versus the TIP122's through-hole TO-220, offering better thermal performance and automated assembly compatibility. Both share similar electrical specs, but the KSH122TF's integrated damper diode and guaranteed h_FE ≥ 1000 at 8 A reduce external component count and base drive burden compared to the TIP122, which lacks the diode and has looser gain tolerance.

Is the KSH122TF suitable for linear amplifier applications?

Yes, the KSH122TF is specified for linear operation with V_BE(on) = 2.8 V at I_C = 4 A and SOA curves covering DC to 100 μs pulses. Its high h_FE and 100 V V_CEO support Class AB audio output stages and precision current sources, provided adequate heatsinking is applied to maintain T_J ≤ 150°C per the Absolute Maximum Ratings.

KSH122TF Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: NPN - Darlington

Current - Collector (Ic) (Max):: 8 A

Voltage - Collector Emitter Breakdown (Max):: 100 V

Vce Saturation (Max) @ Ib, Ic:: 4V @ 80mA, 8A

Current - Collector Cutoff (Max):: 10µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 1000 @ 4A, 4V

Power - Max:: 1.75 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: DPAK

KSH122TF FAQ

1.How can I place an order for KSH122TF through Aetrix?

Please submit a Request for Quotation (RFQ) for KSH122TF 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 KSH122TF reliable?

The price and inventory of KSH122TF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSH122TF is usually 5 days.

3.What payment methods are accepted for KSH122TF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSH122TF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KSH122TF?

KSH122TF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KSH122TF 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 KSH122TF?

For technical support, including KSH122TF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSH122TF requirements.

6.How does Aetrix verify that KSH122TF is sourced from the original manufacturer or authorized distributors?

All KSH122TF 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 KSH122TF meets industry standards.

7.What is the process for return or replacement of KSH122TF?

All KSH122TF units undergo pre-shipment inspection (PSI). If there is an issue with KSH122TF, 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 KSH122TF part is unused and in its original packaging.

Return procedure for KSH122TF:

1.Submit a request within 90 days.

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

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