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onsemi KSC945LTA
- Part No.:
- KSC945LTA
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
KSC945LTA.pdf
- Description:
- TRANS NPN 50V 0.15A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:7,055
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Product details
Overview
KSC945LTA from onsemi is an NPN epitaxial silicon transistor designed for audio-frequency amplification and high-frequency oscillator circuits, with a collector-base voltage rating of 60 V, DC current gain (hFE) of 120–240 at IC = 1.0 mA, and current gain bandwidth product (fT) of 300 MHz typical. It operates in TO-92 3-lead package with emitter-base breakdown voltage of 5 V and maximum collector current of 150 mA.
For engineers reviewing the KSC945LTA datasheet, pinout, applications, or equivalent options, key selection considerations include its fT performance for RF oscillator design, VCEO = 50 V capability for medium-voltage amplifier stages, and thermal resistance of 500 °C/W in standard FR-4 PCB layout.
Technical Context
This transistor employs epitaxial base construction to achieve high-frequency response and stable DC current gain across operating conditions. Its fT = 300 MHz (typical) at VCE = 6 V, IC = 10 mA enables use in VHF oscillator and broadband preamplifier designs up to ~100 MHz.
The device features low saturation voltages-VCE(sat) = 0.15–0.30 V at IC = 100 mA, IB = 10 mA-and noise figure NF = 4.0 dB at VCE = 6 V, IC = 0.5 mA, f = 1 kHz, RS = 500 Ω-making it suitable for low-noise small-signal amplification where power efficiency and signal fidelity are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCBO | 60 V - Maximum reverse bias voltage between collector and base before breakdown; defines safe operation in common-base configurations. |
| VCEO | 50 V - Maximum collector-emitter voltage under open-base condition; sets upper limit for amplifier stage supply rails. |
| hFE | 120–240 - DC current gain range at VCE = 6 V, IC = 1.0 mA; determines base drive requirements for switching or linear operation. |
| fT | 300 MHz (typ) - Current gain bandwidth product; indicates usable frequency limit for small-signal amplification and oscillator loop stability. |
| PD | 250 mW - Maximum power dissipation at TA = 25 °C; derates 2.0 mW/°C above ambient, defining thermal limits on PCB. |
| Cob | 2.5 pF (typ) - Output capacitance at VCB = 6 V, f = 1 MHz; impacts high-frequency gain roll-off and tuning range in oscillator tanks. |
Pinout & Package
Package: TO-92 3-lead plastic case (Case 135AN), lead-formed, Pb-free, with standard pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current output terminal in common-emitter configuration | Provides low-impedance path for majority carriers; connects to ground or emitter resistor in bias networks. |
| 2 (Base) | Control electrode for minority carrier injection | Accepts small input current to modulate collector current; requires current-limiting resistor in digital switch applications. |
| 3 (Collector) | Current input terminal in common-emitter configuration | Receives amplified current; connects to load resistor or tuned circuit in RF oscillator topologies. |
Key Features
| Feature | Design Value |
|---|---|
| High fT performance | 300 MHz typical enables stable oscillation and amplification up to VHF band without external compensation. |
| Low VCE(sat) | 0.15–0.30 V at IC = 100 mA ensures minimal conduction loss in switching and Class-A amplifier stages. |
| Complementary pairing | Designed as NPN complement to KSA733 PNP transistor for push-pull and differential pair implementations. |
| Low noise figure | 4.0 dB at 1 kHz supports high-fidelity audio preamplifier front-ends with minimal signal degradation. |
Applications
| Audio Preamp Stage | RF Local Oscillator |
|---|---|
Use Scenario: Low-noise voltage amplification of microphone or line-level signals in portable audio equipment. IC Role / Device Role / Timing Role: Small-signal NPN amplifier in common-emitter topology with emitter degeneration. Use Value: 4.0 dB noise figure and hFE ≥ 120 ensure clean gain without introducing audible hiss or distortion. | Use Scenario: Fundamental-mode Colpitts or Hartley oscillator generating 30–100 MHz local oscillator signals. IC Role / Device Role / Timing Role: Active gain element sustaining oscillation in LC tank-based feedback loop. Use Value: 300 MHz fT and 2.5 pF Cob support stable oscillation with predictable start-up and frequency accuracy. |
| Medium-Voltage Switch | Signal Coupling Amplifier |
Use Scenario: Driving LED arrays or relay coils from microcontroller GPIO pins in industrial control modules. IC Role / Device Role / Timing Role: Digital switch in common-emitter configuration with base current limiting. Use Value: VCEO = 50 V and IC(max) = 150 mA allow direct interface to 24 V logic loads without external protection. | Use Scenario: AC-coupled gain stage between sensor interface and ADC input in data acquisition systems. IC Role / Device Role / Timing Role: DC-biased small-signal amplifier with capacitive input/output coupling. Use Value: Linear hFE range and low Cob minimize phase shift and amplitude error across 10 kHz–1 MHz bandwidth. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN small-signal transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 2N3904 | fT = 300 MHz (same typ), but VCEO = 40 V (vs. 50 V); hFE min = 100 (vs. 120) | Limited to ≤40 V supply rails; less margin in medium-voltage amplifier designs | Preferred where cost sensitivity outweighs 10 V VCEO margin and hFE consistency |
| BC547B | fT = 300 MHz (same typ), VCEO = 45 V, hFE = 200–450 (wider spread), Cob = 4.5 pF (higher) | Higher gain variability affects bias stability; increased Cob reduces HF gain flatness | Suitable for general-purpose amplification where precise fT/Cob trade-off is not critical |
Compared with 2N3904 and BC547B, the KSC945LTA offers superior VCEO headroom and tighter hFE distribution for reliable medium-voltage oscillator and preamp designs, while maintaining identical fT performance and lower output capacitance for improved high-frequency response.
Availability
KSC945LTA is available at Aetrix Electronics and suitable for audio preamplifiers, RF oscillator circuits, and medium-voltage switching applications requiring stable component supply and long-term obsolescence management.
Supply support for KSC945LTA 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 delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.
The KSC945LTA belongs to onsemi's legacy discrete transistor portfolio, engineered for cost-sensitive, high-reliability analog signal conditioning and RF generation in consumer and industrial electronics.
FAQ
What is the pin configuration of the KSC945LTA?
The KSC945LTA uses a TO-92 3-lead package with standardized pinout: Pin 1 is Emitter, Pin 2 is Base, and Pin 3 is Collector. This configuration is confirmed in the official onsemi datasheet (Publication Order Number KSC945/D, Rev. 3, June 2024) and matches the marking diagram showing "1 2 3" orientation. The KSC945LTA pinout supports common-emitter, common-base, and common-collector topologies without adaptation.
Is the KSC945LTA RoHS-compliant and lead-free?
Yes, the KSC945LTA is Pb-free and RoHS-compliant. The datasheet explicitly lists "TO−92 3 LF (Pb−Free)" in the Ordering Information section, and the part number suffix "LTA" corresponds to the lead-free, tape-and-reel packaging variant (2,000 units per FNFLD). onsemi confirms full compliance with EU RoHS Directive 2011/65/EU and related amendments for this device.
What is the maximum operating temperature for the KSC945LTA?
The KSC945LTA has a maximum junction temperature (TJ) of 150 °C and storage temperature range of −55 to 150 °C. Its thermal resistance RθJA is 500 °C/W on a standard FR-4 PCB (76 mm × 114 mm), meaning power dissipation must be limited to 250 mW at 25 °C ambient, derating by 2.0 mW/°C above that. These values are specified in the Absolute Maximum Ratings and Thermal Characteristics tables of the KSC945LTA datasheet.
Can the KSC945LTA replace the KSC945YTA?
Yes, the KSC945LTA is functionally and physically identical to the KSC945YTA, differing only in packaging format and environmental compliance: KSC945LTA is Pb-free tape-and-reel (FNFLD), while KSC945YTA is marked as discontinued in the datasheet. Both share identical electrical specifications, TO-92 package dimensions, pinout, and thermal characteristics. The KSC945LTA serves as the active, RoHS-compliant replacement for KSC945YTA in new designs.
What is the noise performance of the KSC945LTA in audio applications?
The KSC945LTA has a noise figure (NF) of 4.0 dB at VCE = 6 V, IC = 0.5 mA, f = 1 kHz, and RS = 500 Ω. This measured value makes it suitable for low-noise audio preamplifier stages where signal integrity is critical. The KSC945LTA's low NF, combined with its hFE range of 120–240, ensures consistent gain and minimal added noise in microphone and line-input amplifiers without requiring complex noise-canceling circuitry.
KSC945LTA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Packaging:
- Tape & Box (TB)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 150 mA
- Voltage - Collector Emitter Breakdown (Max):
- 50 V
- Vce Saturation (Max) @ Ib, Ic:
- 300mV @ 10mA, 100mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 350 @ 1mA, 6V
- Power - Max:
- 250 mW
- Frequency - Transition:
- 300MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
KSC945LTA FAQ
1.How can I place an order for KSC945LTA through Aetrix?
Please submit a Request for Quotation (RFQ) for KSC945LTA 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 KSC945LTA reliable?
The price and inventory of KSC945LTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSC945LTA is usually 5 days.
3.What payment methods are accepted for KSC945LTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSC945LTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSC945LTA?
KSC945LTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSC945LTA 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 KSC945LTA?
For technical support, including KSC945LTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSC945LTA requirements.
6.How does Aetrix verify that KSC945LTA is sourced from the original manufacturer or authorized distributors?
All KSC945LTA 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 KSC945LTA meets industry standards.
7.What is the process for return or replacement of KSC945LTA?
All KSC945LTA units undergo pre-shipment inspection (PSI). If there is an issue with KSC945LTA, 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 KSC945LTA part is unused and in its original packaging.
Return procedure for KSC945LTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
KSC945LTA Tags
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