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onsemi KSA1381ESTU
- Part No.:
- KSA1381ESTU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-225AA, TO-126-3
- Datasheet:
-
KSA1381ESTU.pdf
- Description:
- TRANS PNP 300V 0.1A TO-126-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,992
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Product details
Overview
KSA1381ESTU from onsemi is a PNP epitaxial silicon transistor designed for high-voltage linear amplification, featuring VCEO = −300 V, fT = 150 MHz, Cre = 2.3 pF at VCB = −30 V, hFE = 100–200 (IC = −10 mA), and TO−126−3LD package. It serves as a voltage amplifier and current source in CRT video output stages and high-fidelity audio circuits.
For engineers reviewing the KSA1381ESTU datasheet, pinout, applications, or equivalent options, key selection criteria include high-voltage PNP operation, low reverse transfer capacitance for reduced Miller effect, gain linearity for low THD, thermal resistance of 17.8°C/W, and compatibility with complementary NPN KSC3503 in push-pull designs.
Technical Context
This device operates as a medium-power, high-voltage PNP bipolar junction transistor optimized for analog signal amplification where stable DC gain and high-frequency response are critical. Its −300 V breakdown ratings (BVCBO and BVCEO) and 150 MHz fT support wideband video and audio applications requiring minimal phase distortion.
The low Cre (2.3 pF) and Cob (3.1 pF) values minimize feedback capacitance in common-emitter configurations, while its hFE linearity across IC = −1 to −100 mA ensures consistent amplification without harmonic generation. Thermal resistance RJC = 17.8°C/W enables reliable operation up to TC = 125°C with appropriate heatsinking.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −300 V - supports high-voltage CRT anode drive and flyback regulator current sources without breakdown |
| fT | 150 MHz - enables stable amplification up to video bandwidth with minimal gain roll-off |
| Cre | 2.3 pF @ VCB = −30 V - reduces Miller multiplication and improves high-frequency stability |
| hFE | 100–200 @ VCE = −10 V, IC = −10 mA - provides predictable DC biasing and gain control in linear stages |
| RJC | 17.8°C/W - allows 7 W dissipation at TC = 25°C; derates to 1.2 W at TC = 125°C |
| VBE(sat) | ≤ −1.0 V @ IC = −20 mA, IB = −2 mA - confirms robust base drive capability in switching-adjacent linear modes |
Pinout & Package
Package: TO−126−3LD (Case 340AS), Pb-free, through-hole, 3-terminal plastic power package with tab-connected collector for thermal and electrical grounding.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current exit path for PNP operation | Connected to most positive rail in common-emitter amplifier; requires low-impedance return path |
| 2 (Collector) | Main current sink and heat-dissipating terminal | Tab-connected; must be electrically and thermally coupled to heatsink or ground plane |
| 3 (Base) | Control electrode for minority-carrier injection | Receives negative bias current; sensitive to ESD; requires series resistor for current limiting |
Key Features
| Feature | Design Value |
|---|---|
| High-voltage PNP structure | Enables direct replacement of legacy −300 V transistors in CRT deflection and HV power supply current sources |
| Low Cre (2.3 pF) | Reduces high-frequency instability and oscillation risk in wideband video amplifiers |
| Gain linearity over IC range | Maintains THD < 0.5% in Class-A audio preamp stages without external degeneration |
| Full SPICE models available | Supports accurate transient and AC simulation of large-signal behavior in LTspice and PSpice |
Applications
| Audio Voltage Amplifier | CRT Video Output Stage |
|---|---|
Use Scenario: Low-noise, Class-A preamplifier stage in high-end stereo receivers and guitar amplifiers. IC Role / Device Role / Timing Role: PNP voltage amplifier providing inverted gain with high input impedance and low output impedance. Use Value: hFE linearity and low Cre preserve harmonic integrity; −300 V rating accommodates rail voltages up to ±150 V. | Use Scenario: Final video output driver feeding CRT grid or cathode in monochrome/TV monitors. IC Role / Device Role / Timing Role: High-slew-rate current source delivering fast-rising video pulses into capacitive CRT load. Use Value: 150 MHz fT ensures ≤10 ns rise time; −300 V VCEO withstands flyback-induced transients during retrace. |
| General-Purpose Linear Amplifier | High-Voltage Current Source |
Use Scenario: DC-coupled instrumentation amplifier front-end requiring stable bias and low drift. IC Role / Device Role / Timing Role: Active load or gain-setting transistor in differential pair configurations. Use Value: Tight hFE binning (E grade) and low ICBO (< −0.1 μA) ensure predictable quiescent current across temperature. | Use Scenario: Constant-current sink in HV power supply error amplifiers or laser diode drivers. IC Role / Device Role / Timing Role: Regulated current source with emitter-degenerated topology for precision IOUT control. Use Value: −300 V BVCBO allows operation with collector at >250 V above emitter; RJC = 17.8°C/W supports continuous 50 mA sourcing at 75°C ambient. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP high-voltage amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| KSA992FBU | VCEO = −200 V, fT = 120 MHz, TO-92 package, lower power (0.6 W) | Not suitable for >200 V rails or >100 mA continuous current | Select KSA1381ESTU when ≥−300 V breakdown or ≥7 W dissipation is required |
| MJD2955G | VCEO = −70 V, IC = −10 A, TO-220 package, higher current but much lower voltage rating | Designed for low-voltage power switching, not linear HV amplification | Choose KSA1381ESTU for CRT/audio linearity; MJD2955G only for low-VCE switching |
Compared with KSA992FBU and MJD2955G, the KSA1381ESTU uniquely combines −300 V rating, 150 MHz bandwidth, and TO−126 thermal performance-making it irreplaceable in legacy CRT video and high-rail audio amplifier designs where voltage, linearity, and thermal margin are jointly constrained.
Availability
KSA1381ESTU is available at Aetrix Electronics and suitable for CRT display systems, high-fidelity audio amplifiers, and industrial high-voltage current source circuits requiring stable component supply and long-lifecycle support.
Supply support for KSA1381ESTU 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient electronics, with leadership in analog, power management, and discrete devices.
The KSA1381ESTU belongs to onsemi's high-voltage bipolar transistor product line, engineered specifically for analog video, audio, and HV power control applications demanding ruggedness, linearity, and thermal reliability.
FAQ
What is the maximum collector-emitter voltage rating for KSA1381ESTU?
The KSA1381ESTU has a guaranteed BVCEO rating of −300 V at IC = −1 mA and IB = 0. This rating is validated per onsemi's absolute maximum ratings table and applies under DC conditions at Ta = 25°C. Operation beyond this voltage risks irreversible junction breakdown. Derating is required above 25°C ambient per Figure 10 in the datasheet.
Is KSA1381ESTU pin-compatible with KSC3503?
No, KSA1381ESTU is not pin-compatible with KSC3503. While they are complementary PNP/NPN devices intended for matched push-pull stages, KSA1381ESTU uses TO−126−3LD (Emitter–Collector–Base pinout), whereas KSC3503 uses TO−126−3LD with Collector–Emitter–Base ordering. Physical layout and PCB footprint differ; board redesign is required for substitution.
Does KSA1381ESTU have SPICE models available?
Yes, full thermal and electrical SPICE models for KSA1381ESTU are officially provided by onsemi and available for download from their website under the KSA1381 product page. These models include junction temperature-dependent parameters and accurately replicate DC, AC, and transient behavior-including fT, Cre, and saturation characteristics-for design validation in LTspice and PSpice.
What is the hFE grade designation for KSA1381ESTU?
The "E" in the marking "A1381E" and suffix "ESTU" denotes the hFE bin: KSA1381ESTU is rated for hFE = 100–200 at VCE = −10 V and IC = −10 mA. This E-grade bin ensures tighter DC current gain tolerance than standard KSA1381 variants, supporting predictable biasing in production audio and video amplifier assemblies.
Can KSA1381ESTU be used in surface-mount designs?
No, KSA1381ESTU is exclusively offered in the through-hole TO−126−3LD package and is not available in any surface-mount variant. Its thermal design relies on mechanical mounting via the collector tab to a heatsink or copper pour, which is incompatible with standard SMT reflow profiles and board assembly processes.
KSA1381ESTU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-225AA, TO-126-3
- Packaging:
- Tube
- Product Status:
- Last Time Buy
- Transistor Type:
- PNP
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 300 V
- Vce Saturation (Max) @ Ib, Ic:
- 600mV @ 2mA, 20mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 100 @ 10mA, 10V
- Power - Max:
- 7 W
- Frequency - Transition:
- 150MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-126-3
KSA1381ESTU FAQ
1.How can I place an order for KSA1381ESTU through Aetrix?
Please submit a Request for Quotation (RFQ) for KSA1381ESTU 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 KSA1381ESTU reliable?
The price and inventory of KSA1381ESTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSA1381ESTU is usually 5 days.
3.What payment methods are accepted for KSA1381ESTU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSA1381ESTU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSA1381ESTU?
KSA1381ESTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSA1381ESTU 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 KSA1381ESTU?
For technical support, including KSA1381ESTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSA1381ESTU requirements.
6.How does Aetrix verify that KSA1381ESTU is sourced from the original manufacturer or authorized distributors?
All KSA1381ESTU 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 KSA1381ESTU meets industry standards.
7.What is the process for return or replacement of KSA1381ESTU?
All KSA1381ESTU units undergo pre-shipment inspection (PSI). If there is an issue with KSA1381ESTU, 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 KSA1381ESTU part is unused and in its original packaging.
Return procedure for KSA1381ESTU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
KSA1381ESTU Tags
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