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onsemi KSC945GBU
- Part No.:
- KSC945GBU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
KSC945GBU.pdf
- Description:
- TRANS NPN 50V 0.15A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:7,112
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Product details
Overview
KSC945GBU from onsemi is an NPN epitaxial silicon transistor designed for audio-frequency amplification and high-frequency oscillator circuits, with VCBO = 60 V, fT = 300 MHz (typical), IC = 150 mA, VCEO = 50 V, and PD = 250 mW. It operates in TO-92 3-pin package with emitter-base-collector pinout and serves in low-power RF signal generation and small-signal amplification stages.
For engineers reviewing the KSC945GBU datasheet, pinout, applications, or equivalent options, key selection criteria include its 300 MHz fT bandwidth, 120–240 hFE range at 1 mA, 0.15 V VCE(sat) at 100 mA/10 mA drive, 2.5 pF Cob, and suitability for discrete amplifier and oscillator designs requiring Pb-free TO-92 packaging.
Technical Context
This NPN transistor uses epitaxial base construction to achieve high-frequency performance up to 300 MHz fT while maintaining stable DC current gain (hFE = 120–240) across 1–100 mA collector currents. Its low output capacitance (Cob = 2.5 pF) and low saturation voltage support efficient switching and linear amplification in compact analog circuits.
The device features a maximum junction temperature of 150°C and thermal resistance RθJA = 500°C/W on standard FR-4 PCBs, enabling reliable operation in ambient temperatures up to 75°C at full rated power. Complementary pairing with KSA733 allows push-pull configurations in audio and RF stages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCBO | 60 V - supports collector-base reverse bias up to 60 V without breakdown |
| fT | 300 MHz (typ) - enables stable amplification or oscillation up to VHF band |
| hFE | 120–240 - provides predictable small-signal gain control at 1 mA IC |
| VCE(sat) | 0.15 V (typ) at IC = 100 mA, IB = 10 mA - minimizes conduction loss in switching use |
| Cob | 2.5 pF - limits Miller effect and preserves high-frequency stability |
| PD | 250 mW - defines maximum continuous dissipation on standard FR-4 board |
| Noise Figure | 4.0 dB at 1 kHz, RS = 500 Ω - suitable for low-noise preamplifier stages |
Pinout & Package
Package: TO-92 3-pin plastic case (Case 135AN), Pb-free, through-hole mounting. Dimensions: 4.825 mm × 4.76 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current exit path | Connected to ground or low-impedance return; sets bias reference point |
| 2 (Base) | Control input | Receives forward-biased drive current to modulate collector current |
| 3 (Collector) | Current input path | Connects to supply rail or load; carries amplified output current |
Key Features
| Feature | Design Value |
|---|---|
| High fT bandwidth | 300 MHz typical - enables use in VHF oscillator and RF amplifier stages |
| Low VCE(sat) | 0.15 V at 100 mA - reduces power loss and self-heating in switching applications |
| Low noise figure | 4.0 dB at 1 kHz - supports clean signal amplification in audio front-ends |
| Complementary pairing | Matched with KSA733 PNP - simplifies design of Class-A/B audio output stages |
| Pb-free TO-92 | RoHS-compliant leadform - meets environmental compliance without derating |
Applications
| Audio Preamp Stage | Crystal Oscillator Buffer |
|---|---|
Use Scenario: Low-noise voltage amplification of microphone or line-level signals prior to ADC sampling. IC Role / Device Role / Timing Role: Small-signal NPN amplifier operating in common-emitter configuration with fixed bias. Use Value: 4.0 dB noise figure and 120–240 hFE ensure high SNR and stable gain control at 0.5–10 mA collector currents. | Use Scenario: Isolating and driving crystal oscillator output into subsequent logic or mixer stages. IC Role / Device Role / Timing Role: Emitter-follower buffer stage providing low-impedance drive and minimal loading of resonant circuit. Use Value: 2.5 pF Cob and 300 MHz fT preserve oscillator frequency stability and reduce phase perturbation. |
| RF Signal Generator | Discrete Switching Regulator Driver |
Use Scenario: Building compact 30–100 MHz LC-based signal sources for test equipment or sensor excitation. IC Role / Device Role / Timing Role: Active device in Colpitts or Hartley oscillator topology with tuned tank network. Use Value: 300 MHz fT and 60 V VCBO allow reliable operation at fundamental frequencies up to 100 MHz with margin. | Use Scenario: Driving gate of power MOSFET in low-power DC-DC converter feedback or enable path. IC Role / Device Role / Timing Role: Saturated switch controlling logic-level enable/disable signal to power stage. Use Value: 0.15 V VCE(sat) and 150 mA IC rating minimize propagation delay and power loss during switching transitions. |
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), but VCEO = 40 V (vs. 50 V); hFE min = 100 (vs. 120) | Suitable for general-purpose low-voltage amplification; lower VCEO limits high-side switching headroom | Prefer KSC945GBU where ≥50 V VCEO or tighter hFE min is required |
| BC547C | fT = 300 MHz (same), but Cob = 4.5 pF (vs. 2.5 pF); VCEO = 45 V | Better hFE spread (110–800), but higher capacitance reduces HF stability margin | Choose KSC945GBU for RF oscillator or low-capacitance buffer roles |
Compared with 2N3904 and BC547C, the KSC945GBU offers superior VCEO headroom and lower output capacitance-critical for stable high-frequency oscillator design and high-voltage small-signal switching where Cob-induced phase shift must be minimized.
Availability
KSC945GBU is available at Aetrix Electronics and suitable for audio preamplifiers, crystal oscillator buffers, RF signal generators, and discrete switching regulator drivers requiring stable component supply and RoHS-compliant TO-92 packaging.
Supply support for KSC945GBU 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 specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The KSC945GBU belongs to onsemi's legacy discrete transistor product line, engineered for cost-sensitive, high-reliability analog signal conditioning and RF timing applications in space-constrained through-hole designs.
FAQ
What is the pinout configuration of the KSC945GBU?
The KSC945GBU uses a standard TO-92 3-pin layout with pin 1 = Emitter, pin 2 = Base, pin 3 = Collector. This emitter-base-collector order is confirmed in the official onsemi datasheet (Publication Order Number KSC945/D, Rev. 3, June 2024) and matches mechanical outline CASE 135AN. The KSC945GBU does not use center-collector configuration-the "-C" suffix applies only to variants like KSC945CYTA.
Is the KSC945GBU suitable for high-frequency oscillator applications?
Yes, the KSC945GBU is explicitly rated for high-frequency oscillator use per its datasheet Features section. With a typical fT of 300 MHz and low output capacitance (Cob = 2.5 pF), it supports stable operation in Colpitts, Hartley, and Clapp oscillator topologies up to 100 MHz. Its 60 V VCBO also provides margin for resonant voltage swings in tuned circuits.
What is the maximum power dissipation of the KSC945GBU?
The KSC945GBU has a maximum power dissipation (PD) of 250 mW at TA = 25°C, with a derating factor of 2.0 mW/°C above that temperature. This value is measured on a standard FR-4 PCB (76 mm × 114 mm × 1.57 mm) using minimum land pattern size, as defined in the Thermal Characteristics table of the official KSC945/D datasheet.
How does the KSC945GBU compare to the KSC945YTA variant?
The KSC945GBU and KSC945YTA share identical electrical specifications and TO-92 packaging, but differ in packaging format and status: KSC945GBU ships in bulk (10,000 units), is Pb-free, and remains active; KSC945YTA was shipped in tape-and-reel (2,000 units) but is now discontinued per onsemi's ordering information note. Both use CASE 135AN outline and same pinout.
Does the KSC945GBU have a guaranteed minimum hFE value?
Yes, the KSC945GBU guarantees hFE ≥ 120 at VCE = 6 V and IC = 1.0 mA, with a typical value of ~180 and maximum of 240 under those conditions. This minimum is specified in the Electrical Characteristics table of the official datasheet and applies across the full production lot-not just typical or sample units.
KSC945GBU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Packaging:
- Bulk
- 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:
- 200 @ 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
KSC945GBU FAQ
1.How can I place an order for KSC945GBU through Aetrix?
Please submit a Request for Quotation (RFQ) for KSC945GBU 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 KSC945GBU reliable?
The price and inventory of KSC945GBU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSC945GBU is usually 5 days.
3.What payment methods are accepted for KSC945GBU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSC945GBU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KSC945GBU?
KSC945GBU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KSC945GBU 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 KSC945GBU?
For technical support, including KSC945GBU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSC945GBU requirements.
6.How does Aetrix verify that KSC945GBU is sourced from the original manufacturer or authorized distributors?
All KSC945GBU 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 KSC945GBU meets industry standards.
7.What is the process for return or replacement of KSC945GBU?
All KSC945GBU units undergo pre-shipment inspection (PSI). If there is an issue with KSC945GBU, 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 KSC945GBU part is unused and in its original packaging.
Return procedure for KSC945GBU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
KSC945GBU Tags
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