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onsemi BC557BZL1
- Part No.:
- BC557BZL1
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Datasheet:
-
BC557BZL1.pdf
- Description:
- TRANS PNP 45V 0.1A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:8,832
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Product details
Overview
BC557BZL1 from onsemi is a PNP silicon small-signal amplifier transistor in TO-92 package, rated for VCEO = −45 V, IC = −100 mA continuous, hFE = 220–460 at IC = −2 mA, fT = 320 MHz, and VCE(sat) ≤ −0.65 V at IC = −100 mA. It serves as a general-purpose linear amplification or switching element in low-power analog and digital interface circuits.
For engineers reviewing the BC557BZL1 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, TO-92 terminal mapping, real-world use cases in biasing networks and signal inversion stages, and two validated alternative parts with documented hFE, VCEO, and packaging differences.
Technical Context
The BC557BZL1 operates as a discrete PNP bipolar junction transistor optimized for linear amplification and saturated switching in ambient temperatures from −55°C to +150°C. Its DC current gain (hFE) is binned to B-series specification (220–460 at IC = −2 mA), and its fT of 320 MHz supports audio-frequency and low-speed digital signal handling.
Thermal performance is defined by RJA = 200°C/W (ambient) and RJC = 83.3°C/W (case), with safe operating area limited by second breakdown and thermal constraints up to 150°C junction temperature. The device uses standard epoxy-molded TO-92 (Case 29, Style 17) construction with Pb-free plating per onsemi's RoHS-compliant offering.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V - Maximum collector-emitter voltage before breakdown; sets upper rail limit in PNP common-emitter amplifier stages. |
| IC (continuous) | −100 mA - Continuous collector current rating; defines max steady-state load drive capability in switching applications. |
| hFE range | 220–460 @ IC = −2 mA - B-series DC current gain bin; enables predictable bias point setting in Class-A amplifiers. |
| fT | 320 MHz - Current-gain bandwidth product; supports stable gain up to ~100 kHz with margin for audio preamp designs. |
| VCE(sat) | ≤ −0.65 V @ IC = −100 mA, IB = −5 mA - Low saturation voltage ensures minimal power loss in switch-mode operation. |
| RJA | 200°C/W - Junction-to-ambient thermal resistance; requires ≥ 0.5 cm² copper pad for full 625 mW dissipation at 25°C ambient. |
Pinout & Package
BC557BZL1 uses the industry-standard TO-92 package (Case 29, Style 17), with 3 leads molded in epoxy and marked "BC557B" on the body. Lead spacing is 2.54 mm (0.100"), and overall dimensions are 4.45 × 5.20 × 4.19 mm (L × W × H).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Collector) | Main current sink terminal | Connected to positive supply rail in PNP common-emitter configurations; carries full load current during conduction. |
| 2 (Base) | Control input node | Receives forward-biased current to turn on transistor; requires current-limiting resistor to set operating point. |
| 3 (Emitter) | Current source reference | Typically tied to VCC in switching apps or used as output node in emitter-follower buffers. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free TO-92 packaging | Complies with RoHS Directive 2011/65/EU; suitable for lead-free reflow soldering (peak 260°C, 10s). |
| B-series hFE binning | Guaranteed 220–460 at IC = −2 mA, enabling consistent bias design without post-layout trimming. |
| Low VCE(sat) | ≤ −0.65 V at high-current switching ensures <100 mW power loss in 100 mA load switching. |
| High fT | 320 MHz allows stable small-signal gain up to 100 kHz with >20 dB margin, supporting audio and sensor signal conditioning. |
| Wide TJ range | −55°C to +150°C operation supports deployment in automotive under-hood and industrial control environments. |
Applications
| Audio Pre-amplifier Stage | Level-Shifting Interface |
|---|---|
|
Use Scenario: Amplifying weak microphone or piezoelectric sensor signals in battery-powered portable audio devices. IC Role / Device Role / Timing Role: PNP common-emitter small-signal amplifier providing 20–40 dB voltage gain with DC-coupled bias network. Use Value: B-series hFE bin ensures predictable gain stability across production units; fT = 320 MHz avoids high-frequency roll-off in 20 Hz–20 kHz band. |
Use Scenario: Converting 3.3 V logic outputs to interface with 5 V or 12 V legacy peripherals in embedded controllers. IC Role / Device Role / Timing Role: Active pull-up level shifter using emitter-follower configuration with grounded base resistor network. Use Value: VCEO = −45 V supports safe operation with 12 V rails; low VBE(on) ≈ −0.62 V minimizes threshold uncertainty in logic translation. |
| LED Driver Switch | Current Mirror Reference |
|
Use Scenario: Driving indicator LEDs or low-current optocouplers in PLC I/O modules where sourcing current is required. IC Role / Device Role / Timing Role: Saturated PNP switch with base driven by microcontroller GPIO through current-limiting resistor. Use Value: VCE(sat) ≤ −0.65 V limits LED series resistor power loss; IC = −100 mA rating covers typical 20 mA LED loads with margin. |
Use Scenario: Building matched current sources in analog front-ends for sensor excitation or DAC output buffering. IC Role / Device Role / Timing Role: One leg of a discrete PNP current mirror pair, biased with precision reference voltage. Use Value: Tight hFE bin (220–460) improves mirror ratio accuracy; low Cob = 3.0–6.0 pF reduces high-frequency mismatch in AC-coupled mirrors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP small-signal amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC557B (TO-92, bulk) | Identical electrical specs and TO-92 package; differs only in packaging format (5000 pcs/bulk vs. 2000 pcs/ammo box). | No functional difference; suitable for high-volume automated assembly where tape-and-reel not required. | Select BC557B for cost-sensitive production runs with manual or bulk-feed placement equipment. |
| BC857B (SOT-23) | Same B-series hFE, VCEO = −45 V, but surface-mount SOT-23 package; RJA = 300°C/W (higher thermal resistance). | Requires PCB redesign for footprint; better suited for space-constrained layouts where TO-92 is impractical. | Choose BC857B when board area is critical and thermal derating to ≤ 300 mW is acceptable. |
Compared with BC557BZL1, BC557B offers identical performance in bulk packaging for lower unit cost, while BC857B trades TO-92 through-hole compatibility for SOT-23 miniaturization-requiring layout change but enabling higher-density designs.
Availability
BC557BZL1 is available at Aetrix Electronics and suitable for audio preamplification, logic-level translation, and LED driver switching requiring stable component supply across industrial control, test instrumentation, and consumer electronics programs.
Supply support for BC557BZL1 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The BC557BZL1 belongs to onsemi's legacy small-signal transistor family designed for general-purpose linear amplification and switching in cost-sensitive, high-reliability applications across consumer and industrial electronics.
FAQ
What is the maximum continuous collector current rating for BC557BZL1?
The BC557BZL1 has a maximum continuous collector current (IC) rating of −100 mA at TA = 25°C. This value decreases with rising ambient temperature due to thermal derating at 5.0 mW/°C above 25°C, and actual usable current depends on PCB copper area and airflow. The BC557BZL1 must be operated within its SOA curve to avoid second breakdown.
Does BC557BZL1 have Pb-free construction?
Yes, BC557BZL1 is manufactured with Pb-free terminations and complies with RoHS Directive 2011/65/EU. Its TO-92 package uses matte tin plating compatible with standard lead-free reflow profiles (peak 260°C, 10 seconds). The "ZL1" suffix denotes ammo-packaged, Pb-free variant per onsemi's ordering nomenclature.
What is the hFE range guaranteed for BC557BZL1?
The BC557BZL1 is binned to the B-series hFE specification: minimum 220, typical 290, and maximum 460 when measured at IC = −2 mA and VCE = −5.0 V. This binning is confirmed in the Electrical Characteristics table on page 2 of the official BC556B/D datasheet, and applies specifically to BC557B variants including BC557BZL1.
How does BC557BZL1 differ from BC557C in terms of DC current gain?
The BC557BZL1 guarantees hFE = 220–460 at IC = −2 mA, whereas BC557C specifies hFE = 420–800 under identical conditions. The C-series offers higher and wider gain range, making it preferable for ultra-low-base-drive applications, while BC557BZL1 provides tighter mid-range gain control ideal for predictable biasing in production-grade amplifiers.
What is the pin configuration of BC557BZL1 in TO-92 package?
When viewing the flat side of the BC557BZL1 TO-92 package with leads pointing downward, the pinout is: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter (Style 17 per datasheet page 6). This configuration is standardized across all BC556/557/558 variants and verified in the marking diagram and package outline drawing (Case 29).
BC557BZL1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Packaging:
- Bulk
- Product Status:
- Obsolete
- 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):
- 100nA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 180 @ 2mA, 5V
- Power - Max:
- 625 mW
- Frequency - Transition:
- 320MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92 (TO-226)
BC557BZL1 FAQ
1.How can I place an order for BC557BZL1 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC557BZL1 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 BC557BZL1 reliable?
The price and inventory of BC557BZL1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC557BZL1 is usually 5 days.
3.What payment methods are accepted for BC557BZL1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC557BZL1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC557BZL1?
BC557BZL1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC557BZL1 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 BC557BZL1?
For technical support, including BC557BZL1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC557BZL1 requirements.
6.How does Aetrix verify that BC557BZL1 is sourced from the original manufacturer or authorized distributors?
All BC557BZL1 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 BC557BZL1 meets industry standards.
7.What is the process for return or replacement of BC557BZL1?
All BC557BZL1 units undergo pre-shipment inspection (PSI). If there is an issue with BC557BZL1, 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 BC557BZL1 part is unused and in its original packaging.
Return procedure for BC557BZL1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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