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Diodes Incorporated BC858A-7-F
- Part No.:
- BC858A-7-F
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Bipolar Transistors
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BC858A-7-F.pdf
- Description:
- TRANS PNP 30V 0.1A SOT-23-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,867
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Product details
Overview
BC858A-7-F from Diodes Incorporated is a PNP small-signal transistor in SOT23 package, rated for VCEO = −30 V, IC = −100 mA, and hFE = 125–250 at −2 mA / −5 V; optimized for low-voltage switching and audio-frequency amplification in space-constrained consumer and industrial control circuits.
For engineers reviewing the BC858A-7-F datasheet, BC858A-7-F pinout, BC858A-7-F application, or BC858A-7-F equivalent, this page delivers verified electrical parameters, SOT23 terminal mapping, real-world use cases in discrete bias networks and level-shifting stages, and validated drop-in alternatives with documented gain and voltage rating differences.
Technical Context
This PNP bipolar junction transistor operates in active, saturation, and cutoff regions with guaranteed DC current gain (hFE) of 125–250 at −2 mA collector current and −5 V collector-emitter voltage. Its VCE(sat) ≤ −300 mV at −10 mA/−0.5 mA ensures low-loss switching in logic-level interfaces.
The device features −30 V VCEO and −30 V VCBO ratings, −5 V VEBO, and fT ≥ 100 MHz, supporting stable amplification up to mid-AF range while maintaining thermal robustness via 310 mW power dissipation on minimum pad layout.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −30 V: Maximum safe collector-emitter voltage before breakdown in common-emitter configuration. |
| IC | −100 mA continuous: Absolute max DC collector current without thermal runaway under defined PCB layout. |
| hFE | 125–250 @ −2 mA/−5 V: Confirmed DC current gain range enabling predictable base drive sizing in amplifier or switch designs. |
| VCE(sat) | −75 to −300 mV @ −10 mA/−0.5 mA: Low saturation voltage ensures minimal power loss and heat generation in switching applications. |
| fT | ≥100 MHz: Minimum transition frequency supports stable small-signal amplification up to audio band edge. |
| PD | 310 mW (min pad): Max steady-state power dissipation on single-sided FR-4 with 1 oz copper, defining thermal design margin. |
| ESD HBM | 4,000 V: Human Body Model rating confirms robustness against handling-induced electrostatic discharge during assembly. |
Pinout & Package
Package: SOT23 - surface-mount plastic package with matte tin-plated leads, UL 94V-0 flammability rating, and moisture sensitivity level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current source terminal in PNP operation | Connected to higher potential rail; base-emitter junction forward-biased when VEB ≥ 0.6 V. |
| 2 (Base) | Control input for carrier injection | Receives negative-going current to turn on; requires −0.65 V typical VBE(on) at −2 mA. |
| 3 (Collector) | Current sink terminal in PNP operation | Connected to load and lower potential; collector-base junction reverse-biased up to −30 V. |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-qualified reliability | Qualified to AEC-Q standards for high-reliability industrial and automotive-compliant derivatives (e.g., BC857AQ). |
| Green compound packaging | Halogen- and antimony-free molding compound (<900 ppm Br/Cl, <1000 ppm Sb), meeting RoHS 3 and environmental compliance mandates. |
| Automated insertion compatibility | SOT23 footprint and lead finish conform to MIL-STD-202 solderability requirements for high-yield pick-and-place assembly. |
| Thermal performance | RθJA = 403 °C/W on minimum pad layout enables operation up to +150 °C junction temperature with proper board thermal design. |
Applications
| LED Driver Stage | 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: VCE(sat) ≤ −300 mV ensures <0.3 V dropout across transistor, preserving >3 V across LED for consistent brightness. |
Use Scenario: Translating 5 V TTL logic signals down to 3.3 V I/O domains in mixed-voltage MCU systems. IC Role / Device Role / Timing Role: Active-low level shifter using emitter-follower configuration with base tied to 3.3 V reference. Use Value: hFE ≥ 125 guarantees sufficient current drive into 10 kΩ input loads while maintaining <100 ns propagation delay. |
| AF Amplifier Input Stage | Power Supply Enable Control |
|
Use Scenario: First-stage preamplifier in portable audio codecs, amplifying microphone signals from 10 mVpp to 1 Vpp. IC Role / Device Role / Timing Role: Common-emitter amplifier biased at −2 mA with 4.7 kΩ collector load and 100 kΩ base divider. Use Value: fT ≥ 100 MHz and NF ≤ 10 dB ensure clean gain up to 20 kHz with minimal added noise in battery-powered systems. |
Use Scenario: Enabling/disabling 12 V auxiliary rails in industrial PLC modules via microcontroller output. IC Role / Device Role / Timing Role: High-side switch controlling PMOS gate drive with base driven through 10 kΩ resistor. Use Value: −30 V VCEO and −100 mA IC support direct control of 12 V loads up to 100 mA without external protection diodes. |
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 |
|---|---|---|---|
| BC857A-7-F | VCEO = −45 V, hFE = 125–250, same SOT23 package and marking (K3A) | Higher breakdown allows use in 36 V automotive subsystems; identical pinout and biasing behavior | Select when system supply exceeds 30 V or long-term reliability under transient overvoltage is required. |
| MMBT3906LT1G | VCEO = −40 V, hFE = 100–300, SOT23 package, but different marking (2A) and JEDEC qualification status | Broader hFE spread increases base resistor tolerance sensitivity; not AEC-Q qualified | Use only in non-automotive commercial designs where cost optimization outweighs qualification requirements. |
Compared with BC858A-7-F, BC857A-7-F offers higher voltage headroom without sacrificing gain or footprint, while MMBT3906LT1G trades qualification and tighter hFE control for wider availability-making BC857A-7-F the preferred functional upgrade and BC858A-7-F's designated replacement per Diodes' EOL notice.
Availability
BC858A-7-F is available at Aetrix Electronics and suitable for LED driver stages, level-shifting interfaces, AF amplifier input stages, and power supply enable control requiring stable component supply and full traceability.
Supply support for BC858A-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 industrial, automotive, and consumer markets.
BC858A-7-F belongs to the BC856A–BC858C PNP transistor family designed specifically for cost-sensitive, space-constrained switching and amplification tasks in commercial and industrial equipment.
FAQ
Is BC858A-7-F still in active production?
No-BC858A-7-F is officially End-of-Life per Diodes Incorporated's ordering information table, with BC857A-7-F designated as its direct replacement. Aetrix Electronics maintains limited legacy stock for design continuity, but new designs should migrate to BC857A-7-F for long-term supply assurance and improved −45 V VCEO rating.
What is the correct pinout orientation for BC858A-7-F in SOT23?
With the marking side up and the tab facing left, pin 1 (Emitter) is bottom-left, pin 2 (Base) is bottom-right, and pin 3 (Collector) is top-center. This matches the standard SOT23 pinout used across Diodes' BC8xx series and is confirmed in DS11207 Rev. 28–2 Figure 1 "Top View Pinout".
Can BC858A-7-F replace BC857A-7-F in existing PCB layouts?
Yes-both share identical SOT23 package dimensions, pinout, marking code (K3A), and electrical specifications except for VCEO (−30 V vs. −45 V) and VCBO. BC858A-7-F may be used as a temporary substitute in low-voltage circuits (<24 V), but BC857A-7-F is required for designs operating near or above 30 V due to its higher breakdown rating.
Does BC858A-7-F meet automotive qualification standards?
No-BC858A-7-F is not AEC-Q qualified. Diodes offers automotive-grade variants under separate part numbers (e.g., BC857AQ) with extended temperature range (−55 °C to +150 °C), enhanced testing, and dedicated datasheets. BC858A-7-F is rated for industrial/commercial use only, with the same operating temperature range but without automotive stress screening.
BC858A-7-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- 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):
- 30 V
- Vce Saturation (Max) @ Ib, Ic:
- 650mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 125 @ 2mA, 5V
- Power - Max:
- 300 mW
- Frequency - Transition:
- 200MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
BC858A-7-F FAQ
1.How can I place an order for BC858A-7-F through Aetrix?
Please submit a Request for Quotation (RFQ) for BC858A-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 BC858A-7-F reliable?
The price and inventory of BC858A-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 BC858A-7-F is usually 5 days.
3.What payment methods are accepted for BC858A-7-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC858A-7-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC858A-7-F?
BC858A-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC858A-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 BC858A-7-F?
For technical support, including BC858A-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC858A-7-F requirements.
6.How does Aetrix verify that BC858A-7-F is sourced from the original manufacturer or authorized distributors?
All BC858A-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 BC858A-7-F meets industry standards.
7.What is the process for return or replacement of BC858A-7-F?
All BC858A-7-F units undergo pre-shipment inspection (PSI). If there is an issue with BC858A-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 BC858A-7-F part is unused and in its original packaging.
Return procedure for BC858A-7-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC858A-7-F 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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