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onsemi BC557BZL1G
- Part No.:
- BC557BZL1G
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Datasheet:
-
BC557BZL1G.pdf
- Description:
- TRANS PNP 45V 0.1A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:8,556
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Product details
Overview
BC557BZL1G 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) ≤ −0.3 V at IC = −10 mA / IB = −0.5 mA. It serves as a general-purpose switching and linear amplification device in low-power analog and digital interface circuits.
For engineers reviewing the BC557BZL1G datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain consistency across temperature, low saturation voltage for efficient switching, junction-to-ambient thermal resistance (200°C/W), and Pb-free TO-92 mechanical compatibility with legacy through-hole assembly processes.
Technical Context
The BC557BZL1G operates as a discrete PNP bipolar junction transistor optimized for linear amplification and saturated switching in low-voltage, low-current signal paths. Its hFE binning (B-series) guarantees minimum DC current gain of 220 at IC = −2 mA and VCE = −5 V, with typical fT of 320 MHz ensuring usable bandwidth in audio and medium-speed digital applications.
Thermal design is constrained by RJA = 200°C/W and RJC = 83.3°C/W, requiring careful PCB copper area allocation for ambient operation up to +125°C. The device exhibits VBE(on) = −0.62 to −0.7 V and VBE(sat) ≤ −0.7 V, supporting predictable base drive requirements in emitter-follower or common-emitter configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −45 V - Maximum collector-emitter blocking voltage before breakdown; defines safe operating range in negative-rail biasing. |
| IC (continuous) | −100 mA - Continuous collector current limit; sets upper bound for steady-state load driving capability. |
| hFE (min @ IC = −2 mA) | 220 - Minimum DC current gain ensures reliable base-current-controlled switching or amplification without gain collapse. |
| fT | 320 MHz - Transition frequency confirms usable small-signal bandwidth up to ~100 MHz in practical amplifier designs. |
| VCE(sat) (max) | −0.3 V @ IC = −10 mA / IB = −0.5 mA - Low saturation voltage minimizes power loss and heating during switching. |
| RJA | 200°C/W - Junction-to-ambient thermal resistance requires ≥1 cm² of 2-oz copper for safe 625 mW dissipation at TA = 25°C. |
| NF | 2.0 dB @ IC = −0.2 mA - Low noise figure supports use in preamplifier stages where signal integrity is critical. |
Pinout & Package
BC557BZL1G uses the TO-92 (Case 29, Style 17) package with bent leads and Pb-free finish. Dimensions conform to JEDEC TO-226 standard: body height 4.45–5.20 mm, lead pitch 2.54 mm, and maximum outline width 4.32 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Collector) | Main current sink terminal | Connected to negative supply rail or load return path; carries full output current in common-emitter configuration. |
| 2 (Base) | Control input terminal | Receives forward-biased current to turn on transistor; requires series resistor to limit IB per hFE and VBE specs. |
| 3 (Emitter) | Current source terminal | Typically tied to ground or positive rail; provides reference point for VBE bias and defines emitter-follower output node. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free TO-92 packaging | Complies with RoHS Directive 2011/65/EU and supports lead-free reflow or hand-soldering processes without contamination risk. |
| B-series hFE binning | Guarantees hFE ≥ 220 at IC = −2 mA, enabling consistent gain matching in multi-transistor circuits like differential pairs. |
| Low VCE(sat) | ≤ −0.3 V at IC/IB = 10 ensures <15 mW conduction loss at 10 mA, critical for battery-powered switch-mode logic interfaces. |
| High fT | 320 MHz allows stable small-signal amplification up to 50 MHz with adequate phase margin in single-stage CE topologies. |
| Wide TJ range | −55°C to +150°C junction operation supports deployment in automotive under-hood and industrial control environments. |
Applications
| Audio Pre-amplification | Level Translation |
|---|---|
|
Use Scenario: Amplifying microphone-level signals (−10 mV to −100 mV) into line-level range (±1 V) in portable audio recorders. IC Role / Device Role / Timing Role: PNP common-emitter amplifier stage providing 20–40 dB voltage gain with minimal distortion. Use Value: VCE(sat) ≤ −0.3 V and hFE ≥ 220 ensure stable bias point and low THD (<0.5%) at 1 kHz with 1 kΩ collector load. |
Use Scenario: Converting 3.3 V logic outputs to −5 V compatible levels for interfacing with legacy RS-232 transceivers. IC Role / Device Role / Timing Role: Active pull-down switch translating high-Z or positive logic to negative-rail referenced output. Use Value: Fast turn-off (toff < 200 ns per fT = 320 MHz) and guaranteed VCEO = −45 V prevent latch-up during voltage transitions. |
| LED Driver Control | Current Mirror Reference |
|
Use Scenario: Sourcing current to drive indicator LEDs in 5 V or 12 V industrial HMI panels with PWM dimming. IC Role / Device Role / Timing Role: Saturated switch controlling LED anode connection to positive rail via emitter-follower configuration. Use Value: IC = −100 mA rating and VBE(sat) ≤ −0.7 V allow direct microcontroller GPIO drive without external base buffer. |
Use Scenario: Building matched current sources in precision analog sensor signal conditioning circuits (e.g., RTD bridges). IC Role / Device Role / Timing Role: One leg of a discrete PNP current mirror replicating reference current with <5% error over −40°C to +85°C. Use Value: Tight hFE binning (B-series) and low VBE temperature coefficient (−1.8 mV/°C) minimize mirror ratio drift. |
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 |
|---|---|---|---|
| BC557BLT1G | Same electrical specs and B-bin hFE, but in SOT-23 surface-mount package (3.0 × 1.4 × 1.1 mm). | Requires PCB redesign for SMT assembly; unsuitable for through-hole prototyping or repair. | Select when board space is constrained and automated pick-and-place is available. |
| PN2907A | Higher VCEO (−60 V), lower hFE (100 min), same TO-92 package and pinout (Style 2: E-B-C). | Acceptable for higher-voltage switching but less suitable for low-noise amplification due to higher NF (10 dB). | Select when robustness against transient overvoltage is prioritized over gain consistency or noise performance. |
Compared with BC557BZL1G, BC557BLT1G enables miniaturization at the cost of assembly flexibility, while PN2907A trades gain and noise performance for enhanced voltage ruggedness-neither is pin-compatible due to differing pin assignments (BC557BZL1G: C-B-E; PN2907A: E-B-C).
Availability
BC557BZL1G is available at Aetrix Electronics and suitable for audio pre-amplification, level translation, LED driver control, current mirror reference, and general-purpose switching applications requiring stable component supply and RoHS-compliant through-hole assembly.
Supply support for BC557BZL1G 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 manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The BC557BZL1G belongs to onsemi's legacy small-signal transistor family designed for cost-sensitive, high-reliability linear and switching functions in consumer, industrial, and communication equipment.
FAQ
What is the maximum continuous collector current rating for BC557BZL1G?
The BC557BZL1G has a maximum continuous collector current (IC) rating of −100 mA at TA = 25°C. Derating applies above 25°C at 5.0 mW/°C for ambient-limited operation or 12 mW/°C for case-limited operation. This rating ensures safe operation in low-power switching and amplification circuits without thermal runaway under proper PCB heat sinking.
Does BC557BZL1G have a guaranteed minimum DC current gain (hFE)?
Yes, BC557BZL1G is binned as a "B-series" device with a guaranteed minimum hFE of 220 at IC = −2 mA and VCE = −5 V. This specification is verified per onsemi's production test flow and ensures predictable current amplification in bias networks and active loads where gain stability is required.
What is the pin configuration of BC557BZL1G in its TO-92 package?
BC557BZL1G uses TO-92 Style 17 pinout: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter. This differs from common E-B-C arrangements (e.g., PN2907A), so PCB layout and socket orientation must match Style 17 to avoid functional failure or damage during operation.
Is BC557BZL1G suitable for audio-frequency amplification?
Yes, BC557BZL1G is suitable for audio-frequency amplification up to 20 kHz due to its 320 MHz fT, low noise figure (2.0 dB), and stable hFE across temperature. Its VCE(sat) ≤ −0.3 V and VBE(on) = −0.62 to −0.7 V enable clean Class-A or AB biasing in preamp stages with minimal crossover distortion.
What thermal resistance values apply to BC557BZL1G?
BC557BZL1G has RJA = 200°C/W (junction-to-ambient) and RJC = 83.3°C/W (junction-to-case). These values mean that with no heatsink and standard 1 oz copper, the junction temperature rises 200°C per watt dissipated. For 625 mW max power, ambient must stay below 25°C unless additional copper area or airflow is provided.
BC557BZL1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Packaging:
- Cut Tape (CT)
- 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)
BC557BZL1G FAQ
1.How can I place an order for BC557BZL1G through Aetrix?
Please submit a Request for Quotation (RFQ) for BC557BZL1G 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 BC557BZL1G reliable?
The price and inventory of BC557BZL1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC557BZL1G is usually 5 days.
3.What payment methods are accepted for BC557BZL1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC557BZL1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC557BZL1G?
BC557BZL1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC557BZL1G 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 BC557BZL1G?
For technical support, including BC557BZL1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC557BZL1G requirements.
6.How does Aetrix verify that BC557BZL1G is sourced from the original manufacturer or authorized distributors?
All BC557BZL1G 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 BC557BZL1G meets industry standards.
7.What is the process for return or replacement of BC557BZL1G?
All BC557BZL1G units undergo pre-shipment inspection (PSI). If there is an issue with BC557BZL1G, 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 BC557BZL1G part is unused and in its original packaging.
Return procedure for BC557BZL1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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