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onsemi BC857CLT1
- Part No.:
- BC857CLT1
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BC857CLT1.pdf
- Description:
- TRANS PNP 45V 0.1A SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,966
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Product details
Overview
BC857CLT1 from onsemi is a PNP silicon general-purpose transistor in SOT-23 package, rated for −45 V VCEO, −50 V VCBO, −5.0 V VEBO, −100 mA IC continuous, and featuring hFE = 420–800 at IC = −2.0 mA, used in low-voltage switching and amplification circuits in consumer and industrial power management.
For engineers reviewing the BC857CLT1 datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, SOT-23 footprint, guaranteed hFE range (C-grade), −45 V breakdown rating, and AEC-Q101 qualification status for automotive-grade reliability validation.
Technical Context
The BC857CLT1 operates as a discrete bipolar junction transistor with fixed PNP polarity, optimized for linear amplification and saturated switching in low-power analog and digital interface stages. Its electrical behavior is defined by DC current gain (hFE) spanning 420–800 at −2.0 mA collector current and −5.0 V VCE, with VCE(sat) ≤ −0.65 V at −100 mA/−5.0 mA drive.
Thermal performance is characterized by RJA = 556 °C/W on FR-5 board and 417 °C/W on alumina substrate, supporting operation from −55 °C to +150 °C. Small-signal parameters include fT = 100 MHz and Cob = 4.5 pF, confirming suitability for audio-frequency and low-speed digital signal conditioning.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V - Maximum safe collector-emitter voltage before breakdown in open-base configuration; defines upper rail limit in PNP switch designs. |
| hFE | 420–800 at IC = −2.0 mA - Guaranteed DC current gain range for C-grade variant; enables predictable base drive sizing in amplifier and switch bias networks. |
| VCE(sat) | ≤ −0.65 V at IC = −100 mA, IB = −5.0 mA - Low saturation voltage ensures minimal conduction loss in high-efficiency switching applications. |
| fT | 100 MHz - Unity-gain frequency confirms usable bandwidth up to audio and low-speed digital frequencies without significant gain roll-off. |
| Cob | 4.5 pF - Output capacitance limits high-frequency response and affects switching speed in fast-turnoff configurations. |
| PD | 225 mW on FR-5 board - Absolute maximum power dissipation at 25°C ambient; derates linearly at 1.8 mW/°C above that temperature. |
Pinout & Package
SOT-23 (TO-236) surface-mount package, 2.90 × 1.30 × 1.00 mm body size, 1.90 mm lead pitch, JEDEC-standardized outline per Case 318 Style 6.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control terminal for forward-biased PNP operation; requires negative bias relative to emitter to enable conduction. |
| 2 | Emiter | Current source terminal in PNP configuration; connected to higher potential rail in typical common-emitter switch layouts. |
| 3 | Collector | Current sink terminal; output node where load is typically connected between collector and ground or lower-potential rail. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing - supports deployment in under-hood and infotainment systems. |
| Pb-free, RoHS-compliant | Meets EU Directive 2011/65/EU and halogen-free/BFR-free requirements - enables compliance in environmentally regulated end products. |
| C-grade hFE binning | Guaranteed hFE = 420–800 at −2.0 mA/−5.0 V - eliminates need for post-manufacture gain sorting in production assemblies. |
| Low VCE(sat) | ≤ −0.65 V at −100 mA/−5.0 mA - reduces power loss and thermal stress in battery-powered and thermally constrained PCBs. |
Applications
| LED Driver Circuit | Level-Shifting Interface |
|---|---|
Use Scenario: Driving 20 mA indicator LEDs from 3.3 V microcontroller GPIO pins with inverted logic control. IC Role / Device Role / Timing Role: PNP switch configured in common-emitter mode, sinking current from LED anode to ground when base is pulled low. Use Value: Low VCE(sat) minimizes voltage drop across transistor, preserving forward voltage margin for red/green/yellow LEDs at 3.3 V supply. |
Use Scenario: Translating 1.8 V logic-high signals to 5 V rail for legacy peripheral enable lines. IC Role / Device Role / Timing Role: Active-low level shifter using BC857CLT1 as saturated switch controlling pull-up to 5 V. Use Value: Guaranteed hFE ≥ 420 ensures full saturation with minimal base drive current, enabling reliable translation without external bias resistors. |
| Load Switch for Sensor Bias | Audio Pre-amplifier Stage |
Use Scenario: Enabling/disabling power to analog sensor modules (e.g., temperature or humidity ICs) during sleep cycles. IC Role / Device Role / Timing Role: High-side PNP switch placed between VCC and sensor VDD pin, controlled by MCU output. Use Value: −45 V VCEO rating provides ample margin over standard 3.3 V/5 V rails, ensuring robustness against transient overvoltage events. |
Use Scenario: Low-noise pre-amplification of microphone signals in portable audio devices. IC Role / Device Role / Timing Role: Common-emitter amplifier biased in active region, delivering voltage gain with minimal distortion. Use Value: NF = 10 dB at 1 kHz and 0.2 mA collector current enables clean signal amplification without introducing measurable noise floor degradation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP general-purpose transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC857BLT1G | hFE = 220–475 (B-grade), otherwise identical ratings and package | Lower gain range requires larger base resistor or higher drive current for same collector current | Select when tighter hFE tolerance is not required and cost optimization is prioritized. |
| MMBT3906LT1G | Same SOT-23 package but hFE = 100–300 (min–max), VCEO = −40 V, fT = 250 MHz | Higher fT supports faster switching but lower VCEO limits use in 45 V tolerant designs | Prefer for high-speed digital switching where gain consistency is secondary to transition speed. |
Compared with BC857BLT1G and MMBT3906LT1G, the BC857CLT1 offers the highest guaranteed hFE range among SOT-23 PNP transistors in this family, enabling smaller base drive networks and improved stability in precision analog biasing - critical for low-power sensor interfaces and rail-to-rail amplifier stages.
Availability
BC857CLT1 is available at Aetrix Electronics and suitable for LED driver circuits, level-shifting interfaces, sensor load switching, and audio pre-amplifier stages requiring stable component supply, consistent parametric binning, and automotive-grade reliability assurance.
Supply support for BC857CLT1 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 management, analog, sensors, and connectivity solutions for automotive, industrial, and consumer markets.
The BC857CLT1 belongs to the BC856ALT1G Series of general-purpose PNP transistors, designed specifically for cost-sensitive, space-constrained applications requiring AEC-Q101 qualification, tight hFE binning, and robust thermal performance in SOT-23 packaging.
FAQ
What is the maximum collector-emitter voltage rating for BC857CLT1?
The BC857CLT1 has a maximum collector-emitter voltage (VCEO) rating of −45 V at TA = 25°C. This rating applies under open-base conditions and defines the absolute upper limit for voltage across the collector and emitter terminals before risk of avalanche breakdown. Operation beyond this value may cause permanent device failure.
Does BC857CLT1 meet automotive reliability standards?
Yes, the BC857CLT1 is AEC-Q101 qualified and PPAP capable, as confirmed in the official onsemi datasheet. It undergoes rigorous stress testing including temperature cycling, highly accelerated life testing (HALT), and electrostatic discharge (ESD) validation to ensure reliability in automotive environments such as infotainment, body control, and lighting modules.
What is the guaranteed hFE range for BC857CLT1 and at what test conditions?
The BC857CLT1 is binned as "C-grade" with a guaranteed DC current gain (hFE) range of 420 to 800, measured at IC = −2.0 mA and VCE = −5.0 V. This specification is explicitly stated in the Electrical Characteristics table of the onsemi BC856ALT1G Series datasheet and applies to every unit shipped as BC857CLT1.
Is BC857CLT1 RoHS compliant and lead-free?
Yes, BC857CLT1 is Pb-free, halogen-free/BFR-free, and fully RoHS compliant per EU Directive 2011/65/EU. The "G" suffix in the full orderable part number (e.g., BC857CLT1G) explicitly denotes the Pb-free packaging, and this compliance is documented in the onsemi datasheet's Features section and ordering information table.
What is the thermal resistance from junction to ambient for BC857CLT1 on FR-5 board?
The thermal resistance from junction to ambient (RJA) for BC857CLT1 is 556 °C/W when mounted on an FR-5 printed circuit board measuring 1.0 × 0.75 × 0.062 inches. This value assumes natural convection cooling and is used to calculate junction temperature rise under steady-state power dissipation conditions.
BC857CLT1 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):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 45 V
- Vce Saturation (Max) @ Ib, Ic:
- 650mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 420 @ 2mA, 5V
- Power - Max:
- 300 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3 (TO-236)
BC857CLT1 FAQ
1.How can I place an order for BC857CLT1 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857CLT1 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 BC857CLT1 reliable?
The price and inventory of BC857CLT1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857CLT1 is usually 5 days.
3.What payment methods are accepted for BC857CLT1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857CLT1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857CLT1?
BC857CLT1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857CLT1 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 BC857CLT1?
For technical support, including BC857CLT1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857CLT1 requirements.
6.How does Aetrix verify that BC857CLT1 is sourced from the original manufacturer or authorized distributors?
All BC857CLT1 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 BC857CLT1 meets industry standards.
7.What is the process for return or replacement of BC857CLT1?
All BC857CLT1 units undergo pre-shipment inspection (PSI). If there is an issue with BC857CLT1, 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 BC857CLT1 part is unused and in its original packaging.
Return procedure for BC857CLT1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857CLT1 Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
-
MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
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