Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

onsemi KSC1623LMTF

Name: KSC1623LMTF
Brand: onsemi
SKU: KSC1623LMTF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: KSC1623LMTF

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: KSC1623LMTF.pdf

Description:: TRANS NPN 50V 0.1A SOT-23-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:6,911

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

KSC1623LMTF from ON Semiconductor (formerly Fairchild) is an NPN epitaxial silicon transistor designed for low-frequency amplification and high-frequency oscillator applications. It features a 50 V V_CEO, 100 mA I_C, 250 MHz f_T, 3 pF C_ob, and SOT-23 package - commonly used in portable audio preamps and RF local oscillator stages.

For engineers reviewing the KSC1623LMTF datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain classification (L-grade: h_FE = 300–600), saturation voltage at 100 mA/10 mA drive (V_CE(sat) ≤ 0.30 V), and thermal resistance (R_θJA = 625 °C/W).

Technical Context

The KSC1623LMTF operates as a general-purpose bipolar junction transistor with fixed-emitter biasing capability in common-emitter configurations. Its 250 MHz f_T supports stable oscillation up to ~100 MHz in Colpitts or Hartley topologies, while its 3 pF output capacitance minimizes frequency pulling in tuned circuits.

Designed for discrete amplifier stages, it delivers h_FE = 300–600 at I_C = 1 mA and V_CE = 6 V, with V_BE(on) = 0.55–0.65 V and V_CE(sat) ≤ 0.30 V under 100 mA collector current - enabling efficient Class-A small-signal gain with low base drive requirements.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	50 V - Maximum safe collector-emitter voltage before breakdown in common-emitter mode.
I_C	100 mA - Continuous collector current rating defining linear amplification headroom.
f_T	250 MHz - Unity-gain bandwidth confirming suitability for VHF oscillator and RF amplifier use.
C_ob	3 pF - Low output capacitance reducing loading on tank circuits and improving frequency stability.
h_FE (L-grade)	300–600 - Tight DC current gain range enabling predictable bias point setting without trimming.
P_D	200 mW - Power dissipation limit at 25°C ambient, derating 1.6 mW/°C above that temperature.
R_θJA	625 °C/W - Thermal resistance indicating junction-to-ambient heat transfer efficiency on standard FR-4 PCB.

Pinout & Package

Package: SOT-23 (JEDEC TO-236AB), 3-lead, low-profile surface-mount plastic package with gull-wing leads.

Pin/Terminal	Circuit Role	Design Meaning
1 (Base)	Current-controlled input node	Accepts base drive current to modulate collector current; requires external bias network for stable operation.
2 (Emitter)	Common reference terminal	Typically grounded or connected to emitter resistor for DC stabilization in amplifier configurations.
3 (Collector)	Output current terminal	Delivers amplified current to load or tank circuit; polarity-sensitive connection in active region operation.

Key Features

Feature	Design Value
L-grade h_FE binning	300–600 h_FE at I_C = 1 mA ensures consistent small-signal gain across production lots without calibration.
Low V_CE(sat)	≤0.30 V at I_C = 100 mA / I_B = 10 mA reduces conduction loss and improves efficiency in switching-amplifier hybrids.
High f_T	250 MHz enables reliable operation in 30–100 MHz oscillator and RF amplifier designs without gain roll-off.
Low C_ob	3 pF minimizes capacitive loading on resonant circuits, preserving Q-factor and frequency accuracy.

Applications

Portable Audio Preamp	RF Local Oscillator
Use Scenario: Low-noise voltage amplification stage in battery-powered headphone amplifiers and microphone preamplifiers. IC Role / Device Role / Timing Role: NPN small-signal amplifier operating in Class-A common-emitter configuration. Use Value: L-grade h_FE (300–600) ensures stable gain across temperature and unit variance, while 200 mW P_D supports continuous operation within thermal limits.	Use Scenario: Fundamental-mode Colpitts oscillator generating 40–80 MHz clock signals for IF mixing in AM/FM receivers. IC Role / Device Role / Timing Role: Active device sustaining oscillation via positive feedback in tuned LC network. Use Value: 250 MHz f_T and 3 pF C_ob enable clean harmonic suppression and minimal frequency drift under supply variation.
DC Motor Driver Stage	Signal Level Shifter
Use Scenario: Low-side switch driver for 5–12 V brushed DC motors in consumer robotics and actuator modules. IC Role / Device Role / Timing Role: Saturated-switch BJT controlling motor current path to ground. Use Value: V_CE(sat) ≤ 0.30 V at 100 mA reduces power loss and self-heating during PWM-driven on-state operation.	Use Scenario: Logic-level translation between 3.3 V microcontroller GPIO and 5 V peripheral interface lines. IC Role / Device Role / Timing Role: Discrete level-shifting transistor in open-collector or emitter-follower configuration. Use Value: V_BE(on) = 0.55–0.65 V ensures reliable turn-on from 3.3 V logic, while h_FE ≥ 300 guarantees sufficient drive margin.

Portable Audio Preamp

RF Local Oscillator

Use Scenario: Low-noise voltage amplification stage in battery-powered headphone amplifiers and microphone preamplifiers.

IC Role / Device Role / Timing Role: NPN small-signal amplifier operating in Class-A common-emitter configuration.

Use Value: L-grade h_FE (300–600) ensures stable gain across temperature and unit variance, while 200 mW P_D supports continuous operation within thermal limits.

Use Scenario: Fundamental-mode Colpitts oscillator generating 40–80 MHz clock signals for IF mixing in AM/FM receivers.

IC Role / Device Role / Timing Role: Active device sustaining oscillation via positive feedback in tuned LC network.

Use Value: 250 MHz f_T and 3 pF C_ob enable clean harmonic suppression and minimal frequency drift under supply variation.

DC Motor Driver Stage

Signal Level Shifter

Use Scenario: Low-side switch driver for 5–12 V brushed DC motors in consumer robotics and actuator modules.

IC Role / Device Role / Timing Role: Saturated-switch BJT controlling motor current path to ground.

Use Value: V_CE(sat) ≤ 0.30 V at 100 mA reduces power loss and self-heating during PWM-driven on-state operation.

Use Scenario: Logic-level translation between 3.3 V microcontroller GPIO and 5 V peripheral interface lines.

IC Role / Device Role / Timing Role: Discrete level-shifting transistor in open-collector or emitter-follower configuration.

Use Value: V_BE(on) = 0.55–0.65 V ensures reliable turn-on from 3.3 V logic, while h_FE ≥ 300 guarantees sufficient drive margin.

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
MMBT3904LT1G	h_FE = 100–300 (standard grade), lower f_T (300 MHz typical but not guaranteed min), same SOT-23 package.	Less suitable for oscillator designs requiring guaranteed 250 MHz f_T; better for general-purpose switching where gain consistency is secondary.	Select when cost sensitivity outweighs need for tight h_FE binning or oscillator-grade f_T.
BC847BLT1G	h_FE = 200–450 (L-grade), f_T = 100 MHz (min), higher V_CEO = 45 V, same footprint.	Lower bandwidth limits use in >50 MHz oscillator circuits; acceptable for audio and low-speed digital switching.	Choose for industrial control I/O where extended voltage margin and RoHS compliance are prioritized over RF performance.

Compared with MMBT3904LT1G and BC847BLT1G, the KSC1623LMTF provides the highest guaranteed f_T and tightest h_FE range among SOT-23 NPN transistors, making it uniquely suited for stable RF oscillator design where gain-bandwidth predictability is critical.

Availability

KSC1623LMTF is available at Aetrix Electronics and suitable for portable audio preamps, RF local oscillators, DC motor driver stages, and signal level shifters requiring stable component supply and consistent parametric performance across production batches.

Supply support for KSC1623LMTF 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 (formerly Fairchild Semiconductor) is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, and consumer markets.

The KSC1623LMTF belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, engineered for reliability and parametric consistency in analog signal conditioning and RF timing circuits.

FAQ

What is the h_FE range for KSC1623LMTF?

The KSC1623LMTF is binned to the "L" classification, specifying a DC current gain (h_FE) range of 300 to 600 when measured at V_CE = 6 V and I_C = 1 mA. This tight binning allows designers to set bias points confidently without gain-dependent trimming, and is confirmed in the official Fairchild KSC1623 Rev. 1.1.0 datasheet, page 2.

Does KSC1623LMTF support RF oscillator applications?

Yes, the KSC1623LMTF supports RF oscillator applications up to approximately 100 MHz due to its guaranteed minimum current gain bandwidth product (f_T) of 250 MHz at V_CE = 6 V and I_C = 10 mA. Its low 3 pF output capacitance further enhances stability in Colpitts and Hartley oscillator topologies, as documented in the KSC1623 Rev. 1.1.0 datasheet, page 2.

What is the pin configuration of KSC1623LMTF?

The KSC1623LMTF uses the standard SOT-23 package with pin 1 = Base, pin 2 = Emitter, pin 3 = Collector - verified by the physical dimensions diagram (Figure 7) and pin identification note ("1. Base 2. Emitter 3. Collector") in the KSC1623 Rev. 1.1.0 datasheet, page 1 and 4.

What is the maximum power dissipation for KSC1623LMTF?

The KSC1623LMTF has a maximum power dissipation (P_D) of 200 mW at T_A = 25°C, with a derating factor of 1.6 mW/°C above that ambient temperature. This value is defined under standard JEDEC test conditions (FR-4 PCB, 76 mm × 114 mm), and appears in the Absolute Maximum Ratings table on page 1 of the KSC1623 Rev. 1.1.0 datasheet.

Is KSC1623LMTF RoHS compliant?

Yes, KSC1623LMTF is RoHS compliant. As a Fairchild part integrated into ON Semiconductor's portfolio post-2016, it meets EU Directive 2011/65/EU requirements. Compliance is confirmed through ON Semiconductor's official product change notices and material declarations accessible via www.onsemi.com using the KSC1623LMTF part number.

KSC1623LMTF Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 100 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:: 300 @ 1mA, 6V

Power - Max:: 200 mW

Frequency - Transition:: 250MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

KSC1623LMTF FAQ

1.How can I place an order for KSC1623LMTF through Aetrix?

Please submit a Request for Quotation (RFQ) for KSC1623LMTF 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 KSC1623LMTF reliable?

The price and inventory of KSC1623LMTF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KSC1623LMTF is usually 5 days.

3.What payment methods are accepted for KSC1623LMTF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KSC1623LMTF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for KSC1623LMTF?

KSC1623LMTF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your KSC1623LMTF 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 KSC1623LMTF?

For technical support, including KSC1623LMTF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KSC1623LMTF requirements.

6.How does Aetrix verify that KSC1623LMTF is sourced from the original manufacturer or authorized distributors?

All KSC1623LMTF 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 KSC1623LMTF meets industry standards.

7.What is the process for return or replacement of KSC1623LMTF?

All KSC1623LMTF units undergo pre-shipment inspection (PSI). If there is an issue with KSC1623LMTF, 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 KSC1623LMTF part is unused and in its original packaging.

Return procedure for KSC1623LMTF:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…