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Diodes Incorporated BC857AT-7-F
- Part No.:
- BC857AT-7-F
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- SOT-523
- Datasheet:
-
BC857AT-7-F.pdf
- Description:
- TRANS PNP 45V 0.1A SOT-523
- Quantity:
- Payment:
- Shipping:
Inventory:2,612
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Product details
Overview
BC857AT-7-F from Diodes Incorporated is a PNP small-signal transistor in SOT523 package, rated for -45V VCEO, -100mA IC, and 150mW power dissipation, with hFE range of 125–220 at -2mA/-5V. It serves as a general-purpose switching or amplification device in space-constrained consumer and industrial control circuits.
For engineers reviewing the BC857AT-7-F datasheet, BC857AT-7-F pinout, BC857AT-7-F application, or BC857AT-7-F equivalent, key selection criteria include its AEC-Q101 qualification, ultra-small SOT523 footprint, guaranteed hFE binning (A-grade), and -55°C to +150°C operating range for automotive and harsh-environment designs.
Technical Context
This PNP bipolar junction transistor uses epitaxial planar die construction for stable gain and low leakage. Its complementary NPN counterpart is BC847AT-7-F, enabling matched pair use in differential or push-pull configurations.
It operates with VBE(ON) = -600 mV typical at -2mA, VCE(SAT) ≤ -300 mV at -10mA/-0.5mA drive, and fT = 100 MHz - supporting medium-speed switching up to ~10 MHz in low-power logic interface and sensor biasing applications.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | -45 V - Maximum allowable collector-emitter voltage before breakdown in common-emitter configuration |
| IC | -100 mA - Continuous DC collector current rating under thermal limits |
| PD | 150 mW - Max steady-state power dissipation on standard FR-4 PCB with 1 oz copper |
| hFE (A grade) | 125–220 - Guaranteed DC current gain range at VCE = -5 V, IC = -2 mA |
| fT | 100 MHz - Transition frequency defining usable bandwidth for small-signal amplification |
| RθJA | 833 °C/W - Thermal resistance from junction to ambient, indicating heat dissipation capability |
| ESD HBM | 4,000 V - Human Body Model ESD robustness level per JEDEC JESD22-A114 |
Pinout & Package
Package: SOT523 - ultra-small surface-mount plastic package (1.6 mm × 1.6 mm × 0.9 mm), lead-free, halogen-free, and RoHS-compliant, with matte tin-plated terminals solderable per MIL-STD-202.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | E | Current exit path for PNP operation; connects to higher potential node in switching circuits |
| 2 (Base) | B | Control terminal; requires negative bias relative to emitter to turn on device |
| 3 (Collector) | C | Current entry path; typically tied to load or supply rail in high-side switch topology |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive electronics per stress test requirements including temperature cycling and HTRB |
| Ultra-small SOT523 footprint | Enables high-density PCB layouts in wearables, IoT sensors, and compact power management modules |
| Guaranteed hFE binning (A grade) | Ensures predictable current amplification without post-manufacture sorting for gain-critical bias networks |
| Low VCE(SAT) | ≤ -300 mV at -10 mA/-0.5 mA enables efficient low-voltage switching with minimal conduction loss |
Applications
| Automotive Door Module | USB-C Port Protection |
|---|---|
Use Scenario: Driving LED status indicators and small solenoids in door latch assemblies. IC Role / Device Role / Timing Role: PNP switch controlling 12V loads with microcontroller GPIO-level base drive. Use Value: AEC-Q101 qualification ensures reliability across -40°C to +125°C ambient, while SOT523 saves board space in multi-function modules. | Use Scenario: Enabling/disabling VCONN or CC line pull-up resistors in USB-C receptacles. IC Role / Device Role / Timing Role: Low-current PNP switch isolating bias networks during port reconfiguration. Use Value: 4 kV HBM ESD rating protects against handling damage during assembly; low ICBO (<15 nA) prevents leakage-induced false detection. |
| Industrial Sensor Signal Conditioning | White Goods Control Board |
Use Scenario: Biasing op-amp input stages and level-shifting analog sensor outputs. IC Role / Device Role / Timing Role: Active load or current source in precision analog front-ends. Use Value: Tight hFE spread (125–220) improves matching in differential pairs; -55°C to +150°C range supports unheated enclosure deployment. | Use Scenario: Controlling relay coils and indicator LEDs on washing machine main control boards. IC Role / Device Role / Timing Role: General-purpose switching element interfacing MCU outputs to 24V loads. Use Value: 150 mW power rating and 833°C/W RθJA allow direct mounting without heatsinking in thermally isolated zones. |
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 |
|---|---|---|---|
| BC857BW-7-F | SOT323 package (larger footprint), same electrical specs and A-grade hFE | Less suitable for ultra-dense layouts; better thermal performance (RθJA ≈ 650°C/W) | Select when board layout allows larger package and improved thermal margin is prioritized over size |
| MMBT3906LT1G | hFE range 100–300 (no binning), SOT23 package, non-AEC-Q101 | Not qualified for automotive; wider gain variation increases design margining effort | Choose for cost-sensitive industrial or consumer applications where AEC-Q101 is not required |
Compared with BC857BW-7-F and MMBT3906LT1G, BC857AT-7-F uniquely delivers AEC-Q101 compliance, guaranteed A-grade hFE, and the smallest possible footprint (SOT523), making it optimal for space- and reliability-critical automotive and portable electronics.
Availability
BC857AT-7-F is available at Aetrix Electronics and suitable for automotive door modules, USB-C port protection circuits, industrial sensor signal conditioning, and white goods control boards requiring stable component supply and long-term lifecycle support.
Supply support for BC857AT-7-F 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, specializing in high-reliability components for automotive, industrial, and computing markets.
The BC857 series belongs to Diodes' AEC-Q101-qualified small-signal transistor product line, designed specifically for space-constrained, high-stability switching and amplification in automotive body electronics and industrial controls.
FAQ
What is the maximum operating temperature for BC857AT-7-F?
The BC857AT-7-F has an operating junction temperature range of -55°C to +150°C, verified per AEC-Q101 stress testing. Its storage temperature matches this range, and derating begins above +25°C ambient per the published thermal resistance curve (RθJA = 833°C/W).
Is BC857AT-7-F pin-compatible with BC847AT-7-F?
No - BC857AT-7-F (PNP) and BC847AT-7-F (NPN) share identical SOT523 pinout (E-B-C), but their polarity and biasing requirements differ fundamentally. They are complementary devices, not drop-in replacements; circuit redesign is required when swapping between them.
Does BC857AT-7-F require external base current limiting in switching applications?
Yes - like all bipolar transistors, BC857AT-7-F requires a current-limiting resistor between the driving GPIO and base terminal to prevent excessive IB. For IC = -10 mA and hFE ≥ 125, minimum IB = -80 µA; typical design uses 10–47 kΩ with 3.3V logic to ensure saturation while avoiding overdrive.
How does the SOT523 package affect thermal performance compared to SOT23?
The SOT523 package reduces thermal mass and PCB copper area, resulting in higher RθJA (833°C/W vs. ~300°C/W for SOT23). This limits continuous power handling unless board layout includes thermal vias or extended copper pours - confirmed by Diodes' derating curves showing 150 mW max only at +25°C ambient.
BC857AT-7-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- SOT-523
- 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:
- 150 mW
- Frequency - Transition:
- 100MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-523
BC857AT-7-F FAQ
1.How can I place an order for BC857AT-7-F through Aetrix?
Please submit a Request for Quotation (RFQ) for BC857AT-7-F 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 BC857AT-7-F reliable?
The price and inventory of BC857AT-7-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC857AT-7-F is usually 5 days.
3.What payment methods are accepted for BC857AT-7-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC857AT-7-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC857AT-7-F?
BC857AT-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC857AT-7-F 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 BC857AT-7-F?
For technical support, including BC857AT-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC857AT-7-F requirements.
6.How does Aetrix verify that BC857AT-7-F is sourced from the original manufacturer or authorized distributors?
All BC857AT-7-F 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 BC857AT-7-F meets industry standards.
7.What is the process for return or replacement of BC857AT-7-F?
All BC857AT-7-F units undergo pre-shipment inspection (PSI). If there is an issue with BC857AT-7-F, 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 BC857AT-7-F part is unused and in its original packaging.
Return procedure for BC857AT-7-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC857AT-7-F Tags
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