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onsemi KST5087MTF
- Part No.:
- KST5087MTF
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
KST5087MTF.pdf
- Description:
- TRANS PNP 50V 0.05A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:8,498
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Product details
Overview
KST5087MTF from ON Semiconductor is a PNP epitaxial silicon transistor optimized for low-noise amplifier and switching applications, featuring -50 V collector-emitter breakdown voltage, 250–800 DC current gain (hFE) at IC = -1 mA to -10 mA, and -0.3 V collector-emitter saturation voltage at IC = -10 mA/IB = -1 mA. It operates in SOT-23 package and is commonly used in portable audio preamplifiers and battery-powered sensor signal conditioning circuits.
For engineers reviewing the KST5087MTF datasheet, pinout, applications, or equivalent options, key selection considerations include its low noise figure (2 dB at IC = -20 mA), high fT of 40 MHz, SOT-23 footprint compatibility, and PNP polarity with -50 V VCEO rating for rail-to-rail negative supply designs.
Technical Context
The KST5087MTF is a discrete PNP bipolar junction transistor with epitaxial base construction, enabling stable hFE across collector current range and low 1/f noise performance. Its design targets analog front-end stages where low input-referred noise and predictable gain linearity are critical.
It supports operation up to 40 MHz fT with Cob = 4 pF at VCB = -5 V, and maintains VBE(sat) ≤ -0.85 V under forced beta = 10, making it suitable for fast-switching and low-distortion linear amplification in compact, low-power systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | -50 V - Supports operation with up to 50 V negative supply rails without breakdown |
| hFE (IC = -1 mA) | 250–800 - Enables high-current gain stability in bias-sensitive amplifier stages |
| VCE(sat) | -0.3 V @ IC = -10 mA/IB = -1 mA - Minimizes conduction loss in saturated switch mode |
| NF | 2 dB @ IC = -20 mA - Delivers low input-referred noise for sensitive analog signal paths |
| fT | 40 MHz @ VCE = -5 V/IC = -500 µA - Supports RF and wideband audio frequency amplification |
| Cob | 4 pF @ VCB = -5 V - Limits Miller capacitance impact on high-frequency gain roll-off |
Pinout & Package
Package: SOT-23 (3-pin, surface-mount, JEDEC MO-178 variant). Standard pin assignment per marking orientation: Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Base) | Control terminal for minority-carrier injection | Accepts forward-biased current to enable PNP conduction; requires negative drive relative to emitter |
| 2 (Emitter) | Source of majority carriers (holes) | Typically connected to higher-potential node in PNP configuration; sets reference for VBE and bias stability |
| 3 (Collector) | Output terminal collecting minority carriers | Connected to load or next stage; handles up to -50 mA continuous current with thermal derating |
Key Features
| Feature | Design Value |
|---|---|
| Low noise figure | 2 dB at IC = -20 mA - Reduces signal degradation in microphone preamps and sensor interfaces |
| High DC current gain | hFE ≥ 250 at IC = -1 mA - Allows low-base-drive designs, reducing upstream driver loading |
| Fast switching capability | fT = 40 MHz - Enables use in >10 MHz small-signal amplifiers and pulse generators |
| SOT-23 footprint | Standardized 3-pin package - Ensures board-level compatibility with automated placement and reflow processes |
Applications
| Portable Audio Preamp | Low-Power Sensor Interface |
|---|---|
Use Scenario: Amplifying weak signals from electret microphones or piezoelectric sensors in battery-powered wearables. IC Role / Device Role / Timing Role: PNP small-signal amplifier providing high-input-impedance, low-noise gain before ADC sampling. Use Value: 2 dB noise figure and 250+ hFE ensure clean signal capture with minimal battery drain in sub-100 µA bias configurations. | Use Scenario: Conditioning output from thermistor or photodiode networks in IoT environmental monitors. IC Role / Device Role / Timing Role: Transimpedance or emitter-follower buffer stage converting high-impedance sensor output to robust voltage drive. Use Value: -0.3 V VCE(sat) and -0.85 V VBE(sat) enable rail-efficient operation from 3.3 V or lower supplies with tight headroom margins. |
| Discrete Logic Level Shifter | Battery Protection Circuit Switch |
Use Scenario: Bidirectional level translation between 5 V microcontroller GPIO and 3.3 V peripheral logic in mixed-voltage embedded systems. IC Role / Device Role / Timing Role: Saturated PNP switch controlling pull-up path to higher rail while isolating lower-voltage domain. Use Value: Fast turn-on/off (enabled by 40 MHz fT) and low VCE(sat) minimize propagation delay and voltage drop during state transitions. | Use Scenario: Overvoltage cutoff in Li-ion battery packs using discrete protection FET gate control. IC Role / Device Role / Timing Role: High-side PNP switch driving gate of N-channel MOSFET in charge/discharge path management. Use Value: -50 V VCEO and 350 mW power dissipation allow safe operation across full battery voltage range (0–4.3 V) with margin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP low-noise transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MMBT5087 | Same die, identical hFE/NF/fT specs; differs only in tape-and-reel packaging and manufacturer branding (ON Semi vs legacy Fairchild) | No functional difference; fully interchangeable in circuit design and layout | Select MMBT5087 when sourcing from distributors listing ON Semiconductor's current nomenclature |
| KST5087 | Identical electrical specs and SOT-23 pinout; KST5087MTF is the tape-and-reel variant with moisture-sensitive packaging per J-STD-020 | No application divergence; same thermal and electrical behavior under identical PCB layout | Choose KST5087MTF for automated SMT production requiring MSL1-rated reels |
Compared with MMBT5087 and KST5087, the KST5087MTF offers identical transistor performance but is specifically qualified for high-volume automated assembly with MSL1 handling and standard 3,000-unit reels-critical for OEM manufacturing continuity and first-pass yield.
Availability
KST5087MTF is available at Aetrix Electronics and suitable for portable audio preamplifiers, low-power sensor interfaces, and discrete logic level shifters requiring stable component supply, consistent parametric performance, and SOT-23 footprint reliability.
Supply support for KST5087MTF 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 supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and edge applications.
The KST5087MTF belongs to ON Semiconductor's legacy Fairchild discrete transistor portfolio, engineered for high-fidelity analog signal conditioning and low-power switching in space-constrained consumer and industrial electronics.
FAQ
What is the maximum collector-emitter voltage rating for KST5087MTF?
The KST5087MTF has a maximum collector-emitter voltage (VCEO) rating of -50 V at Ta = 25°C. This rating ensures safe operation in negative-rail circuits up to 50 V, including battery-powered systems with stacked cells or regulated negative supplies. Derating is required above 25°C ambient per the datasheet thermal curves.
Does KST5087MTF have a specified noise figure, and under what conditions?
Yes, the KST5087MTF has a specified noise figure of 2 dB at IC = -20 mA, VCE = -5 V, RS = 10 kΩ, and f = 10 Hz to 15.7 kHz. This value reflects its suitability for low-noise preamplifier stages in audio and sensor signal chains where input-referred noise directly impacts SNR.
What is the pin configuration of KST5087MTF in the SOT-23 package?
The KST5087MTF uses standard SOT-23 pinout: Pin 1 = Base, Pin 2 = Emitter, Pin 3 = Collector, with marking "2Q" on the top surface. This matches JEDEC MO-178 and is verified in the official ON Semiconductor datasheet revision A2.
How does the DC current gain (hFE) of KST5087MTF vary with collector current?
The KST5087MTF exhibits hFE = 250–800 at IC = -1 mA, hFE = 150–250 at IC = -10 mA, and hFE = 150–500 at IC = -100 µA (VCE = -5 V). This wide gain range supports flexible biasing strategies-from ultra-low-current standby modes to moderate-drive active stages-without external gain stabilization.
Is KST5087MTF suitable for high-frequency amplifier designs?
Yes, the KST5087MTF supports high-frequency operation with a current gain bandwidth product (fT) of 40 MHz at VCE = -5 V and IC = -500 µA. Its 4 pF output capacitance (Cob) and low saturation voltages make it viable for small-signal amplification up to ~10 MHz in well-designed layouts with proper grounding and decoupling.
KST5087MTF 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:
- PNP
- Current - Collector (Ic) (Max):
- 50 mA
- Voltage - Collector Emitter Breakdown (Max):
- 50 V
- Vce Saturation (Max) @ Ib, Ic:
- 300mV @ 1mA, 10mA
- Current - Collector Cutoff (Max):
- 50nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 250 @ 100µA, 5V
- Power - Max:
- 350 mW
- Frequency - Transition:
- 40MHz
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
KST5087MTF FAQ
1.How can I place an order for KST5087MTF through Aetrix?
Please submit a Request for Quotation (RFQ) for KST5087MTF 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 KST5087MTF reliable?
The price and inventory of KST5087MTF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KST5087MTF is usually 5 days.
3.What payment methods are accepted for KST5087MTF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KST5087MTF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KST5087MTF?
KST5087MTF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KST5087MTF 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 KST5087MTF?
For technical support, including KST5087MTF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KST5087MTF requirements.
6.How does Aetrix verify that KST5087MTF is sourced from the original manufacturer or authorized distributors?
All KST5087MTF 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 KST5087MTF meets industry standards.
7.What is the process for return or replacement of KST5087MTF?
All KST5087MTF units undergo pre-shipment inspection (PSI). If there is an issue with KST5087MTF, 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 KST5087MTF part is unused and in its original packaging.
Return procedure for KST5087MTF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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