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Diodes Incorporated BC857CWQ-7
- Part No.:
- BC857CWQ-7
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- SC-70, SOT-323
- Datasheet:
-
BC857CWQ-7.pdf
- Description:
- TRANS PNP 45V 0.1A SOT-323
- Quantity:
- Payment:
- Shipping:
Inventory:2,885
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Product details
Overview
BC857CWQ-7 from Diodes Incorporated is a 45V PNP small-signal bipolar junction transistor (BJT) in SOT323 package, rated for -100mA continuous collector current, -45V VCEO, and AEC-Q101 qualified for automotive use. It delivers hFE of 420–800 at -2mA/-5V and VCE(sat) as low as -75mV at -10mA/-0.5mA, enabling reliable switching and audio-frequency amplification in space-constrained automotive control modules.
For engineers reviewing the BC857CWQ-7 datasheet, BC857CWQ-7 pinout, BC857CWQ-7 application, or BC857CWQ-7 equivalent, key selection criteria include its automotive qualification status, SOT323 thermal resistance (625°C/W), complementary pairing with BC847CWQ, and verified performance under -65°C to +150°C operating range.
Technical Context
This PNP BJT operates in active, saturation, and cutoff regions for analog amplification and digital switching. Its high DC current gain (hFE = 420–800) supports low-base-drive designs, while fT ≥ 100MHz enables stable AF amplifier operation up to ~200kHz bandwidth.
Designed for automotive environments, it features ESD robustness (HBM 4000V, CDM 1000V), halogen/antimony-free "Green" construction, and is manufactured in IATF16949-certified facilities with PPAP capability - ensuring traceable, change-controlled supply for safety-critical subsystems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | -45V - Supports rail-to-rail switching in 36V automotive systems with margin |
| IC (cont.) | -100mA - Handles typical load currents in body control modules and sensor interfaces |
| hFE | 420–800 @ -2mA/-5V - Enables low-power base drive in discrete logic and level-shifting circuits |
| VCE(sat) | -75mV min @ -10mA/-0.5mA - Minimizes conduction loss in high-efficiency switch applications |
| fT | 100–200MHz - Ensures stable gain and phase response in AF amplifiers up to 200kHz |
| RθJA | 625°C/W - Requires minimal PCB copper area for thermal management in SOT323 footprint |
| ESD HBM | 4000V - Meets automotive ESD immunity requirements per ISO 10605 |
Pinout & Package
Package: SOT323 - Surface-mount plastic package with 0.65mm lead pitch, 0.006g mass, and UL 94V-0 flammability rating. Moisture sensitivity level 1 (J-STD-020).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current source terminal for PNP operation | Connected to higher potential rail; must be biased above base and collector for active mode |
| 2 (Base) | Control input for minority-carrier injection | Receives negative current to turn on; requires current-limiting resistor in most switch configurations |
| 3 (Collector) | Current sink terminal | Typically connected to load and ground return path; voltage swing limited to ≤ -45V relative to emitter |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive temperature (-65°C to +150°C), humidity, and vibration stress profiles |
| Complementary NPN pairing | BC847CWQ shares identical SOT323 footprint and biasing characteristics for push-pull designs |
| Low VCE(sat) | -75mV at IC/IB = 10 ensures <1% power loss in 10mA switching loads |
| Halogen- and antimony-free | Meets automotive "Green" standards (<900ppm Br/Cl, <1000ppm Sb) without compromising solderability |
| Matte tin-plated leads | Solderable per MIL-STD-202 Method 208; compatible with lead-free reflow profiles |
Applications
| Automotive Door Module Control | Engine Coolant Sensor Interface |
|---|---|
Use Scenario: Driving LED indicators and small relays in door latch assemblies with 12V/24V battery rails. IC Role / Device Role / Timing Role: PNP switch controlling current flow from battery to load; operates in saturation/cutoff states. Use Value: Low VCE(sat) minimizes heat generation in sealed modules; AEC-Q101 qualification ensures reliability over 15-year vehicle lifetime. | Use Scenario: Level-shifting and signal conditioning between analog sensor outputs and 3.3V microcontroller ADC inputs. IC Role / Device Role / Timing Role: Discrete emitter-follower buffer providing impedance isolation and rail-compatible voltage translation. Use Value: High hFE maintains signal fidelity at µA-level sensor currents; wide TJ range accommodates under-hood thermal cycling. |
| Body Control Unit (BCU) Power Sequencing | Passive Entry RF Receiver Biasing |
Use Scenario: Enabling/disabling auxiliary power rails (e.g., LIN transceiver, EEPROM) during ignition state transitions. IC Role / Device Role / Timing Role: High-side switch managing controlled power-up/down sequencing via MCU GPIO. Use Value: -45V VCEO withstands load-dump transients; SOT323 footprint saves board space in multi-rail BCU layouts. | Use Scenario: Providing stable bias current to low-noise RF amplifier stages in keyless entry receivers. IC Role / Device Role / Timing Role: Constant-current source setting quiescent point for MMIC front-end devices. Use Value: NF ≤ 10dB at 1kHz supports clean sub-13.56MHz signal recovery; low leakage (ICBO ≤ -4µA @ 150°C) prevents drift in hot chassis environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP small-signal transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC857BWT1G | Same VCEO (-45V), but hFE bin 220–475; SOT-323 package, RoHS-compliant | Lacks AEC-Q101 qualification and PPAP support; not approved for automotive production | Select only for non-automotive industrial prototypes where qualification overhead is unnecessary |
| MMBT5551-7-F | PNP counterpart unavailable; this is NPN - mismatched polarity; different VCEO (+160V) and package (SOT-23) | Not functionally substitutable due to polarity and pinout incompatibility | Avoid as direct replacement; consider only if redesigning circuit topology to accommodate NPN high-side drive |
Compared with BC857BWT1G, BC857CWQ-7 provides higher hFE consistency and automotive qualification - critical for production BOMs. Unlike MMBT5551-7-F, it avoids costly layout changes by preserving PNP functionality and SOT323 footprint.
Availability
BC857CWQ-7 is available at Aetrix Electronics and suitable for automotive door modules, engine sensor interfaces, body control unit power sequencing, and passive entry RF receiver biasing requiring stable component supply across extended temperature and lifecycle demands.
Supply support for BC857CWQ-7 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and distribution operations across Asia, Europe, and the Americas.
The BC857CWQ-7 belongs to Diodes' automotive-qualified small-signal transistor product line, engineered specifically for AEC-Q101 compliance, high-reliability switching, and analog signal conditioning in harsh-temperature vehicle subsystems.
FAQ
What is the maximum allowable ambient temperature for continuous operation of BC857CWQ-7?
The device is rated for TJ = -65°C to +150°C, and with RθJA = 625°C/W, maximum continuous ambient temperature depends on power dissipation. At PD = 200mW (full rating), TA max = 150°C − (0.2W × 625°C/W) = 25°C. Derating is required above 25°C per Figure 1 in the datasheet.
Is BC857CWQ-7 pin-compatible with BC847CWQ?
No - BC857CWQ-7 (PNP) and BC847CWQ (NPN) share identical SOT323 package and pinout (E-B-C), but opposite polarity. They are complementary, not interchangeable; swapping requires circuit inversion (e.g., changing high-side to low-side drive).
Does BC857CWQ-7 support lead-free reflow soldering?
Yes - it features matte tin-plated leads compliant with MIL-STD-202 Method 208 and qualified for standard Pb-free reflow profiles (peak temperature ≤ 260°C). The "Green" molding compound meets JEDEC J-STD-020 moisture sensitivity level 1.
How does the BC857CWQ-7 differ from generic BC857 variants?
BC857CWQ-7 is specifically qualified to AEC-Q101, manufactured in IATF16949 facilities, and PPAP-capable - unlike commercial-grade BC857C parts. It also carries automotive-specific marking (K3G), tighter hFE binning (420–800), and guaranteed performance across -65°C to +150°C.
BC857CWQ-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SC-70, SOT-323
- Packaging:
- Bulk
- 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:
- 420 @ 2mA, 5V
- Power - Max:
- 200 mW
- Frequency - Transition:
- 200MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-323
BC857CWQ-7 FAQ
1.How can I place an order for BC857CWQ-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857CWQ-7 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 BC857CWQ-7 reliable?
The price and inventory of BC857CWQ-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857CWQ-7 is usually 5 days.
3.What payment methods are accepted for BC857CWQ-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857CWQ-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857CWQ-7?
BC857CWQ-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857CWQ-7 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 BC857CWQ-7?
For technical support, including BC857CWQ-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857CWQ-7 requirements.
6.How does Aetrix verify that BC857CWQ-7 is sourced from the original manufacturer or authorized distributors?
All BC857CWQ-7 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 BC857CWQ-7 meets industry standards.
7.What is the process for return or replacement of BC857CWQ-7?
All BC857CWQ-7 units undergo pre-shipment inspection (PSI). If there is an issue with BC857CWQ-7, 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 BC857CWQ-7 part is unused and in its original packaging.
Return procedure for BC857CWQ-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857CWQ-7 Tags
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