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Nexperia USA Inc. BC857A-QR
- Part No.:
- BC857A-QR
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BC857A-QR.pdf
- Description:
- TRANS PNP 45V 0.1A TO-236AB
- Quantity:
- Payment:
- Shipping:
Inventory:8,872
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Product details
Overview
BC857A-QR from Nexperia is a PNP general-purpose bipolar junction transistor (BJT) in SOT23 package, designed for low-voltage switching and linear amplification in automotive and industrial control circuits. It features VCEO = −45 V, IC = −100 mA, hFE = 125–250 (at VCE = −5 V, IC = −2 mA), and AEC-Q101 qualification for under-hood automotive use.
For engineers reviewing the BC857A-QR datasheet, BC857A-QR pinout, BC857A-QR application, or BC857A-QR equivalent, this page delivers verified electrical parameters, validated SOT23 terminal mapping, automotive-grade reliability context, and direct substitution guidance against industry-standard PNP transistors with matching gain band and voltage rating.
Technical Context
This device operates as a current-controlled PNP switch or small-signal amplifier with fixed emitter-base and collector-base junction architecture. Its DC current gain (hFE) is binned to 125–250 at IC = −2 mA, VCE = −5 V, and it maintains stable VCE(sat) ≤ −700 mV at IC = −10 mA, IB = −0.5 mA.
Thermal resistance Rth(j-a) is 500 K/W on standard FR4 PCB, supporting continuous operation up to Tj = 150 °C. Absolute maximum ratings include VCBO = −50 V, VEBO = −5 V, and Ptot = 250 mW at Tamb ≤ 25 °C - all defined per IEC 60134 limiting values.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V: Maximum allowable collector-emitter voltage before breakdown in open-base configuration; defines safe operating range in 24 V automotive load-switching applications. |
| IC | −100 mA: Continuous DC collector current rating; supports driving small relays, LEDs, or logic-level interface loads without derating at 25 °C ambient. |
| hFE | 125–250: DC current gain at VCE = −5 V, IC = −2 mA; enables predictable base drive sizing for saturation in switching designs. |
| VCE(sat) | ≤ −700 mV at IC = −10 mA, IB = −0.5 mA; ensures low conduction loss and minimal power dissipation in active-low switch configurations. |
| fT | 100 MHz: Transition frequency at VCE = −5 V, IC = −10 mA; confirms suitability for audio-frequency amplification and fast digital signal conditioning. |
| AEC-Q101 | Qualified: Meets stress test requirements for discrete semiconductors in automotive environments; supports deployment in engine control modules and body electronics. |
Pinout & Package
SOT23 (TO-236AB) plastic surface-mounted package with 3 leads; standardized footprint compatible with reflow and wave soldering per IPC-7351B.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base (B) | Current-controlled input node; requires series resistor to limit IB and ensure saturation at target IC. |
| 2 | Emitter (E) | Common reference terminal for PNP operation; connected to higher potential rail in high-side switch topologies. |
| 3 | Collector (C) | Output current path; sinks load current when B-E junction is forward-biased and C-E is in active/saturation region. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive under-hood temperature cycling, humidity, and mechanical shock per AEC standard - eliminates need for additional qualification testing. |
| Low VCE(sat) | ≤ −700 mV at IC = −10 mA enables <10 mW conduction loss in 5 V logic-driven switches, reducing thermal stress on PCB traces. |
| Controlled hFE binning | 125–250 gain range ensures consistent base drive requirements across production lots, simplifying BOM consolidation and layout reuse. |
| Small SOT23 footprint | 2.9 mm × 1.3 mm × 1.0 mm outline allows dense placement in space-constrained ECUs and sensor modules without thermal crowding. |
Applications
| Automotive Door Module | Industrial PLC Input Stage |
|---|---|
Use Scenario: Driving window lift motor enable signals and mirror fold/unfold solenoids in door control units. IC Role / Device Role / Timing Role: PNP switch controlling 12 V/24 V loads via microcontroller GPIO with inverted logic level. Use Value: −45 V VCEO withstands load-dump transients up to ISO 7637-2 Pulse 5a; AEC-Q101 compliance ensures 15-year field reliability. |
Use Scenario: Level-shifting and isolation of 24 V sensor inputs into 3.3 V microcontroller ADC channels. IC Role / Device Role / Timing Role: Emitter-follower buffer providing galvanic decoupling and current gain for analog signal conditioning. Use Value: 100 MHz fT preserves signal integrity up to 10 kHz sensor bandwidth; low noise figure (2–10 dB) minimizes measurement error. |
| Consumer Appliance Control Board | Medical Diagnostic Sensor Interface |
Use Scenario: Enabling LED status indicators and buzzer drivers in washing machine main control boards. IC Role / Device Role / Timing Role: Low-power saturated switch interfacing MCU outputs to indicator loads. Use Value: −700 mV VCE(sat) limits heat generation in sealed enclosures; 250 mW Ptot supports continuous duty cycle without heatsinking. |
Use Scenario: Amplifying weak bio-potential signals (e.g., ECG front-end) before ADC sampling. IC Role / Device Role / Timing Role: Small-signal common-emitter amplifier stage with bias-stable hFE binning. Use Value: 125–250 hFE range enables precise gain calibration; low ICBO (<4 µA at 150 °C) prevents drift in temperature-sensitive measurements. |
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 |
|---|---|---|---|
| BC847A-Q | NPN complement with identical hFE bin (125–250), same SOT23 package, but opposite polarity and VCEO = +45 V. | Requires circuit topology inversion (e.g., low-side vs. high-side switching); not drop-in for PNP-referenced bias networks. | Select only when redesigning for NPN logic compatibility or when sourcing both polarities for complementary stages. |
| MMBT3906 | Same PNP polarity, VCEO = −40 V, hFE = 100–300, but not AEC-Q101 qualified and has higher VCE(sat) (≤ −850 mV). | Limited to non-automotive industrial or consumer use; unsuitable for safety-critical or temperature-cycled automotive modules. | Choose for cost-sensitive non-automotive designs where AEC-Q101 is not mandated and marginally higher saturation voltage is acceptable. |
Compared with BC847A-Q and MMBT3906, BC857A-QR provides guaranteed automotive qualification, tighter VCE(sat), and design-consistent PNP topology - making it the preferred choice for high-reliability 12 V/24 V load control where polarity and qualification are fixed constraints.
Availability
BC857A-QR is available at Aetrix Electronics and suitable for automotive body electronics, industrial programmable logic controllers, and medical sensor interface modules requiring stable component supply across extended product lifecycles.
Supply support for BC857A-QR 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
Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance, reliable discrete and logic devices for automotive, industrial, and consumer markets.
The BC857-Q series belongs to Nexperia's AEC-Q101-qualified general-purpose transistor product line, engineered specifically for robust, cost-effective switching and amplification in harsh-environment automotive electronics.
FAQ
What is the maximum junction temperature for BC857A-QR?
The absolute maximum junction temperature (Tj) is 150 °C, as specified in Table 6 of the Nexperia datasheet. This rating assumes operation within limiting values and proper PCB thermal management - including use of standard FR4 with 35 µm copper and tin-plated finish per the thermal test condition.
Is BC857A-QR pin-compatible with BC857B-Q or BC857C-Q?
Yes - all BC857-x-Q variants share identical SOT23 pinout (B-E-C), package dimensions, and thermal footprint. However, hFE bins differ: BC857A-Q is 125–250, BC857B-Q is 220–475, and BC857C-Q is 420–800. Substitution requires verification of gain-dependent bias stability in the target circuit.
Does BC857A-QR support wave soldering?
Yes - Nexperia provides dedicated wave soldering footprint data (Figure 16) with recommended solder land dimensions (2.8 mm × 1.4 mm per pad) and transport direction guidance. The SOT23 package is qualified for both reflow and wave processes per IPC-J-STD-020 and J-STD-001 standards.
What marking code identifies BC857A-QR on the device body?
The top-side marking is "3E%", where "3E" is the type-specific code for BC857A-Q and "%" is a placeholder for the manufacturing site identifier (e.g., "3E1" or "3EA"). This matches Table 5 in the official Nexperia datasheet Rev. 2 (2022-02-21).
BC857A-QR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- TO-236-3, SC-59, SOT-23-3
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- 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:
- 125 @ 2mA, 5V
- Power - Max:
- 250 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-236AB
BC857A-QR FAQ
1.How can I place an order for BC857A-QR through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857A-QR 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 BC857A-QR reliable?
The price and inventory of BC857A-QR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857A-QR is usually 5 days.
3.What payment methods are accepted for BC857A-QR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857A-QR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857A-QR?
BC857A-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857A-QR 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 BC857A-QR?
For technical support, including BC857A-QR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857A-QR requirements.
6.How does Aetrix verify that BC857A-QR is sourced from the original manufacturer or authorized distributors?
All BC857A-QR 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 BC857A-QR meets industry standards.
7.What is the process for return or replacement of BC857A-QR?
All BC857A-QR units undergo pre-shipment inspection (PSI). If there is an issue with BC857A-QR, 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 BC857A-QR part is unused and in its original packaging.
Return procedure for BC857A-QR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857A-QR Tags
-
MMBT3906LT1G
onsemi
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MMBT3904-7-F
Diodes Incorporated
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MMBT3904LT1G
onsemi
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MMBT3906-7-F
Diodes Incorporated
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MMBT3904-TP
Micro Commercial Co
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MMBT2222A-7-F
Diodes Incorporated
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BC846BLT1G
onsemi
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BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
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MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
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