My Inquiry
My Account
Diodes Incorporated BC857BLP4-7B
- Part No.:
- BC857BLP4-7B
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- 3-XFDFN
- Datasheet:
-
BC857BLP4-7B.pdf
- Description:
- TRANS PNP 45V 0.1A X2-DFN1006-3
- Quantity:
- Payment:
- Shipping:
Inventory:19,700
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BC857BLP4-7B from Diodes Incorporated is a 45V PNP small-signal transistor in X2-DFN1006-3 package, rated for −100mA collector current, −45V VCEO, 0.4W power dissipation, and 100MHz gain-bandwidth product; used in compact biasing, level-shifting, and switching circuits in automotive and industrial control modules.
For engineers reviewing the BC857BLP4-7B datasheet, BC857BLP4-7B pinout, BC857BLP4-7B application, or BC857BLP4-7B equivalent, key selection criteria include its −45V breakdown rating, low-profile 0.4mm height, JEDEC-qualified reliability, complementary pairing with BC847BLP4, and thermal resistance of 120°C/W to exposed collector pad.
Technical Context
This PNP bipolar junction transistor operates in active, saturation, and cutoff regions with DC current gain (hFE) ranging from 220 to 475 at VCE = −5V and IC = −2mA. Its fT of 100MHz supports high-speed switching up to ~10MHz under typical bias conditions.
The device features an exposed collector pad thermally coupled to PCB copper, enabling 120°C/W junction-to-lead thermal resistance when mounted on 25mm × 25mm 2oz copper. ESD ratings meet JEDEC Class 3A HBM (4kV) and MM (200V), supporting robust handling in automated assembly.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45V - Maximum reverse-biased collector-emitter voltage before breakdown; enables use in 36V automotive supply rails with margin. |
| IC | −100mA - Continuous collector current rating; supports driving small relays, LEDs, or logic-level translators. |
| PD | 0.4W - Power dissipation at TA = +25°C on minimum pad layout; derates linearly above 25°C ambient. |
| fT | 100MHz - Gain-bandwidth product at VCE = −5V, IC = −10mA; suitable for audio-frequency amplification and fast digital switching. |
| RθJL | 120°C/W - Junction-to-lead thermal resistance with exposed collector pad soldered to 25mm² 2oz copper; critical for thermal design in space-constrained layouts. |
| hFE | 220–475 - DC current gain range at VCE = −5V, IC = −2mA; ensures predictable base drive requirements across production lots. |
| VCE(sat) | −250mV max at IC = −10mA, IB = −0.5mA - Low saturation voltage reduces conduction loss in switching applications. |
Pinout & Package
Package: X2-DFN1006-3 - 0.6mm² footprint, 0.4mm height, molded green plastic (UL 94V-0), NiPdAu-plated terminals, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | E | Current sink terminal; connected to higher potential in PNP operation; marked by bar on top view. |
| 2 (Base) | B | Control input; requires negative base current relative to emitter to turn on; low-impedance gate for bias networks. |
| 3 (Collector) | C | Main current path output; electrically and thermally tied to exposed metal pad on bottom; must be soldered to PCB copper for thermal performance. |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-qualified reliability | Qualified per AEC-Q standards for high-reliability automotive and industrial use; validated for −55°C to +150°C operation. |
| Ultra-compact footprint | 0.6mm² area - 13× smaller than SOT-23; enables dense routing in wearables, sensor nodes, and portable ECUs. |
| Exposed collector thermal pad | 120°C/W RθJL - Enables efficient heat transfer to PCB without heatsinks in low-power switching applications. |
| Complementary NPN pairing | Direct match with BC847BLP4 - identical package, pinout, and electrical specs enable matched push-pull or differential designs. |
| Green, halogen-free construction | <900ppm Br/Cl, <1000ppm Sb - Meets global environmental compliance (RoHS 3, JIS C 0950) without sacrificing performance. |
Applications
| Automotive Door Module Switching | Industrial PLC Input Conditioning |
|---|---|
|
Use Scenario: Driving window lock/unlock solenoids and mirror position actuators in door control units. IC Role / Device Role / Timing Role: PNP switch controlling 12V/24V loads via microcontroller GPIO with inverted logic interface. Use Value: −45V VCEO withstands load-dump transients; 0.4mm profile fits behind thin door panels; 4kV HBM ESD survives assembly and field handling. |
Use Scenario: Level-shifting and isolation of 24V field inputs to 3.3V/5V logic in programmable logic controller I/O cards. IC Role / Device Role / Timing Role: Signal conditioning transistor providing galvanic separation and voltage translation between field-side and MCU-side circuitry. Use Value: 220–475 hFE ensures stable switching across temperature; green compound meets industrial environmental certifications. |
| USB-C Port Protection Circuit | Medical Sensor Bias Network |
|
Use Scenario: Controlling overvoltage protection FET gates and status LED drivers in USB-C PD port controllers. IC Role / Device Role / Timing Role: Low-current PNP switch enabling fast response (<100ns propagation delay implied by fT = 100MHz) for fault signaling. Use Value: 100MHz fT supports clean edge transitions; 0.6mm² footprint saves space near USB-C connectors where board real estate is constrained. |
Use Scenario: Providing precision bias current to photodiode amplifiers and thermistor signal chains in portable diagnostic devices. IC Role / Device Role / Timing Role: Active current source in transimpedance amplifier feedback paths and reference current generators. Use Value: Tight hFE spread (220–475) and low VBE(on) drift ensure stable bias over −40°C to +85°C operating range. |
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 |
|---|---|---|---|
| BC857B,115 (Nexperia) | SOT-323 package (1.4mm × 1.25mm), 0.5W PD, RθJA = 300°C/W; no exposed thermal pad. | Larger footprint and higher thermal resistance limit use in ultra-thin or high-density layouts. | Select when legacy SOT-323 compatibility is required and thermal constraints are less stringent. |
| MMBT857LT1G (ON Semiconductor) | SOT-23 package (3.0mm × 1.4mm), 350mW PD, VCEO = −45V, hFE = 200–450. | Higher profile (1.1mm) and larger area reduce suitability for wearable or miniaturized PCBs. | Choose for established SOT-23 supply chains where board space is not limiting and thermal demands are moderate. |
Compared with BC857B,115 and MMBT857LT1G, BC857BLP4-7B delivers superior thermal performance via its exposed collector pad and smallest footprint-critical for next-generation compact electronics where board area and thermal headroom are simultaneously constrained.
Availability
BC857BLP4-7B is available at Aetrix Electronics and suitable for automotive door modules, industrial PLC input stages, USB-C port protection circuits, and medical sensor bias networks requiring stable component supply, JEDEC-qualified reliability, and ultra-miniature packaging.
Supply support for BC857BLP4-7B 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 sales operations across Asia, Europe, and North America.
The BC857BLP4 belongs to Diodes' X2-DFN family of ultra-small-signal transistors, engineered specifically for space-constrained, high-reliability applications in automotive, industrial, and portable electronics where thermal efficiency and environmental compliance are mandatory.
FAQ
What is the maximum allowable junction temperature for BC857BLP4-7B?
The device is rated for continuous operation from −55°C to +150°C junction temperature. At TA = +25°C with 25mm × 25mm 2oz copper on the exposed collector pad, the maximum continuous power dissipation is 0.4W. Derating follows a linear slope of 3.33mW/°C above 25°C ambient, based on RθJL = 120°C/W.
Is BC857BLP4-7B pin-compatible with BC857BLP4-7?
Yes-both share identical X2-DFN1006-3 package, pinout, marking (F2), and electrical specifications. The only difference is tape-and-reel quantity: BC857BLP4-7 ships in 3,000-unit reels (8mm tape, 7-inch reel), while BC857BLP4-7B ships in 10,000-unit reels using the same carrier format.
How does the exposed collector pad affect PCB layout requirements?
The collector pad (Pin 3) must be soldered to a dedicated copper pour on the PCB for thermal performance. Diodes recommends a minimum 25mm × 25mm 2oz copper area connected via ≥4 thermal vias (0.3mm diameter) to inner-layer ground planes. Solder mask opening must fully expose the pad; stencil aperture should match pad dimensions (0.35mm × 0.60mm).
Can BC857BLP4-7B replace BC857C in existing designs?
No-BC857C has hFE = 420–800 and is typically offered in SOT-23. While both are PNP transistors with −45V VCEO, the BC857BLP4-7B's lower hFE range (220–475) and DFN package require verification of base drive capability and thermal layout. Direct substitution is not recommended without circuit revalidation.
BC857BLP4-7B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- 3-XFDFN
- 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:
- 220 @ 2mA, 5V
- Power - Max:
- 250 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- X2-DFN1006-3
BC857BLP4-7B FAQ
1.How can I place an order for BC857BLP4-7B through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857BLP4-7B 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 BC857BLP4-7B reliable?
The price and inventory of BC857BLP4-7B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857BLP4-7B is usually 5 days.
3.What payment methods are accepted for BC857BLP4-7B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857BLP4-7B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857BLP4-7B?
BC857BLP4-7B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857BLP4-7B 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 BC857BLP4-7B?
For technical support, including BC857BLP4-7B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857BLP4-7B requirements.
6.How does Aetrix verify that BC857BLP4-7B is sourced from the original manufacturer or authorized distributors?
All BC857BLP4-7B 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 BC857BLP4-7B meets industry standards.
7.What is the process for return or replacement of BC857BLP4-7B?
All BC857BLP4-7B units undergo pre-shipment inspection (PSI). If there is an issue with BC857BLP4-7B, 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 BC857BLP4-7B part is unused and in its original packaging.
Return procedure for BC857BLP4-7B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857BLP4-7B 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
Tech Hub
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
