My Inquiry
My Account
onsemi BC556CBU
- Part No.:
- BC556CBU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA)
- Datasheet:
-
BC556CBU.pdf
- Description:
- TRANS PNP 65V 0.1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,010
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BC556CBU from onsemi is a PNP epitaxial silicon transistor designed for general-purpose switching and linear amplification in low-to-medium power circuits, with confirmed VCEO = −65 V, IC = −100 mA DC, hFE = 420–800 (Class C), VCE(sat) ≤ −650 mV at IC = −100 mA, and TO-92-3 (Case 135AN) package. It serves in discrete bias networks, level-shifting stages, and relay drivers where high-voltage PNP operation is required.
For engineers reviewing the BC556CBU datasheet, pinout, applications, or equivalent options, key selection considerations include its −65 V collector-emitter breakdown rating, Class C current gain binning, Pb-free RoHS-compliant construction, and compatibility with complementary NPN BC546–BC550 series in push-pull or differential pair configurations.
Technical Context
The BC556CBU operates as a medium-gain, medium-voltage PNP bipolar junction transistor optimized for DC-coupled amplification and saturated switching. Its hFE range of 420–800 (Class C) enables stable biasing in emitter-follower and common-emitter topologies without excessive base drive, while VCEO = −65 V supports use in higher-rail industrial supply rails.
Thermal performance is defined by RJA = 250 °C/W and PD = 500 mW at TA = 25 °C, with derating at 4.0 mW/°C above ambient. Its fT = 150 MHz and Cob = 6 pF support moderate-frequency signal handling up to several tens of MHz in small-signal amplifier stages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −65 V - Supports operation in negative-rail circuits up to −65 V without breakdown |
| IC (DC) | −100 mA - Sustains continuous collector current for driver-stage loads like LEDs or small relays |
| hFE (Class C) | 420–800 - Enables precise DC bias design with low base-current sensitivity in amplifier stages |
| VCE(sat) | ≤ −650 mV @ IC = −100 mA, IB = −5 mA - Ensures low conduction loss in saturated switch applications |
| fT | 150 MHz - Permits use in audio preamps and RF front-end buffer stages up to ~20 MHz |
| Cob | 6 pF @ VCB = −10 V - Minimizes Miller capacitance impact on high-frequency stability |
| PD | 500 mW @ 25°C - Defines maximum dissipation before thermal derating begins |
Pinout & Package
BC556CBU uses the TO-92-3 package (Case 135AN), a through-hole plastic package with 3 leads, standardized leadform for manual and automated insertion. Dimensions: 4.825 mm × 4.76 mm footprint, 4.7 mm height.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Collector) | Main current sink terminal | Connected to most negative potential in circuit; carries full load current in switching mode |
| 2 (Base) | Control input for minority-carrier injection | Requires negative current relative to emitter to turn on; drives bias network impedance |
| 3 (Emitter) | Current source reference terminal | Typically tied to circuit ground or positive rail; sets voltage reference for VBE control |
Key Features
| Feature | Design Value |
|---|---|
| High-voltage PNP structure | VCEO = −65 V enables use in −48 V telecom supplies and industrial negative-rail systems |
| Class C hFE binning | Guaranteed 420–800 gain ensures predictable DC operating point in amplifier bias networks |
| Low-noise capability | NF = 2–10 dB @ 1 kHz allows use in microphone preamp and sensor interface stages |
| Pb-free, RoHS-compliant | Meets global environmental compliance requirements for commercial and industrial PCB assembly |
| Complementary pairing | Designed as direct PNP counterpart to BC546–BC550 NPN series for matched differential pairs |
Applications
| Audio Signal Amplification | Relay Driver Circuit |
|---|---|
Use Scenario: Low-noise preamplifier stage for electret microphone signals in portable audio devices. IC Role / Device Role / Timing Role: PNP common-emitter amplifier providing 20–30 dB voltage gain with minimal added noise. Use Value: Class C hFE and NF ≤ 10 dB ensure consistent gain and SNR across production units without trimming. |
Use Scenario: Driving 12 V DC coil relays in programmable logic controller (PLC) output modules. IC Role / Device Role / Timing Role: Saturated PNP switch sinking relay coil current from positive rail to ground. Use Value: VCEO = −65 V provides margin against inductive kickback spikes up to −50 V. |
| Level-Shifting Interface | Differential Pair Biasing |
Use Scenario: Translating logic-level signals between −5 V and 0 V domains in legacy instrumentation interfaces. IC Role / Device Role / Timing Role: Emitter-follower configured for bidirectional level translation with low output impedance. Use Value: VEB(on) ≈ −0.7 V and low VCE(sat) enable accurate offset tracking and fast edge response. |
Use Scenario: Active load and current mirror elements in discrete op-amp input stages. IC Role / Device Role / Timing Role: Matched PNP pair (with BC556A/B variants) establishing precision tail current and common-mode rejection. Use Value: Tight hFE binning and complementary NPN/PNP symmetry improve CMRR > 70 dB in discrete designs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP general-purpose transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC557BTA | VCEO = −45 V, hFE = 200–450 (Class B), same TO-92-3 package | Limited to lower-voltage rails; less gain headroom in high-precision bias networks | Select when −45 V max operating voltage suffices and tighter hFE tolerance is not required |
| BC856BMTF | SOT-23 surface-mount package, VCEO = −65 V, hFE = 220–475, IC = −100 mA | Not pin-compatible; requires PCB redesign but enables high-density layout | Choose for space-constrained designs where reflow assembly and board area savings outweigh through-hole convenience |
Compared with BC557BTA and BC856BMTF, the BC556CBU delivers highest guaranteed hFE (420–800) and full −65 V rating in a through-hole package-making it optimal for legacy-replacement, high-reliability, or prototyping scenarios requiring maximum gain margin and voltage headroom.
Availability
BC556CBU is available at Aetrix Electronics and suitable for relay driver circuits, audio preamplifiers, level-shifting interfaces, and discrete differential pair designs requiring stable component supply and long-term obsolescence resilience.
Supply support for BC556CBU 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, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The BC556CBU belongs to onsemi's legacy BC-series general-purpose bipolar transistor family, engineered for robustness, wide temperature operation (−65°C to +150°C), and seamless integration into cost-sensitive analog and discrete digital circuits.
FAQ
What is the exact package type and lead configuration for BC556CBU?
The BC556CBU uses the TO-92-3 package (Case 135AN), with leads arranged in straight-line configuration: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter. This mechanical outline is documented in onsemi's package drawing 98AON13880G and verified for BC556CBU in the official datasheet revision dated July 2016.
Does BC556CBU have a specified noise figure, and under what conditions?
Yes, BC556CBU has a noise figure of 2–10 dB, measured at VCE = −5 V, IC = −200 µA, f = 1 kHz, and RG = 2 kΩ. This value applies specifically to the BC556/BC557/BC558 variants per the Electrical Characteristics table on page 2 of the onsemi datasheet.
Is BC556CBU pin-compatible with BC556BTA or BC556ATA?
Yes, BC556CBU shares identical pinout, package (TO-92-3 Case 135AN), and electrical specifications with BC556BTA and BC556ATA - differing only in hFE classification (Class C vs. Class B/A) and packaging format (bulk vs. fan-fold). All three are mechanically and electrically interchangeable in existing layouts.
What is the maximum safe operating junction temperature for BC556CBU?
The BC556CBU has a maximum junction temperature (TJ) of 150°C, as specified in the Absolute Maximum Ratings table. Operation beyond this limit risks permanent degradation of hFE, leakage current, and long-term reliability - even if ambient temperature remains within −65°C to +150°C storage range.
How does BC556CBU compare to BC559C in terms of voltage rating and noise performance?
BC556CBU offers VCEO = −65 V versus BC559C's VCEO = −30 V, making it suitable for higher-voltage rails. However, BC559C has superior low-noise performance (NF = 1.2–4.0 dB) due to optimized epitaxial layer design, while BC556CBU's NF is 2–10 dB - appropriate for general amplification but not ultra-low-noise sensor front-ends.
BC556CBU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- PNP
- Current - Collector (Ic) (Max):
- 100 mA
- Voltage - Collector Emitter Breakdown (Max):
- 65 V
- Vce Saturation (Max) @ Ib, Ic:
- 650mV @ 5mA, 100mA
- Current - Collector Cutoff (Max):
- 15nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 420 @ 2mA, 5V
- Power - Max:
- 500 mW
- Frequency - Transition:
- 150MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
BC556CBU FAQ
1.How can I place an order for BC556CBU through Aetrix?
Please submit a Request for Quotation (RFQ) for BC556CBU 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 BC556CBU reliable?
The price and inventory of BC556CBU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC556CBU is usually 5 days.
3.What payment methods are accepted for BC556CBU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC556CBU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC556CBU?
BC556CBU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC556CBU 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 BC556CBU?
For technical support, including BC556CBU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC556CBU requirements.
6.How does Aetrix verify that BC556CBU is sourced from the original manufacturer or authorized distributors?
All BC556CBU 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 BC556CBU meets industry standards.
7.What is the process for return or replacement of BC556CBU?
All BC556CBU units undergo pre-shipment inspection (PSI). If there is an issue with BC556CBU, 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 BC556CBU part is unused and in its original packaging.
Return procedure for BC556CBU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC556CBU 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
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
