My Inquiry
My Account
onsemi BC556CTA
- Part No.:
- BC556CTA
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
BC556CTA.pdf
- Description:
- TRANS PNP 65V 0.1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:7,758
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BC556CTA from onsemi is a PNP epitaxial silicon transistor designed for general-purpose switching and linear amplification in low-power analog and digital circuits. It features −65 V collector-emitter breakdown voltage (VCEO), 110–800 DC current gain (hFE), −300 mV saturation voltage at −10 mA/−0.5 mA, 150 MHz transition frequency (fT), and TO-92-3 package with verified pinout (Collector-Base-Emitter). It is commonly used in discrete amplifier stages, level-shifting interfaces, and relay drivers.
For engineers reviewing the BC556CTA datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, −65 V VCEO, hFE classification C (420–800), thermal resistance of 250 °C/W, and compatibility with legacy BC5xx complementary designs.
Technical Context
The BC556CTA operates as a medium-voltage, low-noise PNP bipolar junction transistor optimized for stable DC biasing and small-signal amplification. Its hFE classification C ensures high current gain consistency across production lots, while its −65 V VCEO rating supports operation in higher-voltage rails up to −65 V with safe margin.
Thermal performance is defined by a 250 °C/W junction-to-ambient thermal resistance under standard FR-4 PCB conditions (76 mm × 114 mm), and its 500 mW total power dissipation derates linearly at 4.0 mW/°C above 25 °C ambient - enabling predictable thermal design in compact layouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −65 V: Maximum safe collector-emitter reverse voltage before breakdown; enables use in −48 V telecom supplies and industrial control rails. |
| hFE (Class C) | 420–800 at −5 V VCE, −2 mA IC: High, tightly binned DC gain improves bias stability in amplifier feedback networks. |
| VCE(sat) | −300 mV max at −10 mA IC, −0.5 mA IB: Low saturation voltage reduces conduction loss in switching applications. |
| fT | 150 MHz: Supports audio-frequency amplification and fast digital switching up to ~10–20 MHz with adequate gain margin. |
| RθJA | 250 °C/W: Predictable thermal rise on standard PCB; requires ≤125 °C ambient for full 500 mW operation. |
| Cob | 6 pF at −10 V VCB: Low output capacitance minimizes high-frequency signal loading in RF-coupled stages. |
Pinout & Package
BC556CTA is housed in a TO-92-3 plastic package (Case 135AR), lead-formed, with standardized pinout: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter. The package measures 4.83 mm × 4.76 mm and is RoHS-compliant, Pb-free, and halogen-free.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Collector | Main current sink terminal; connects to negative supply rail or load return path in PNP configurations. |
| Pin 2 | Base | Control input; requires current-limited drive (e.g., via series resistor) to avoid exceeding −200 mA peak base current. |
| Pin 3 | Emitter | Current source terminal; typically tied to positive supply in common-emitter switching or bias networks. |
Key Features
| Feature | Design Value |
|---|---|
| High-voltage PNP operation | −65 V VCEO enables reliable use in −48 V systems and industrial power rails without derating. |
| Class C hFE binning | 420–800 gain range ensures consistent bias point setting across production units in amplifier designs. |
| Low-noise performance | 2–10 dB noise figure at 1 kHz supports clean signal amplification in preamp and sensor interface stages. |
| Pb-free, RoHS-compliant packaging | TO-92-3 case 135AR meets global environmental compliance requirements for commercial and industrial assembly. |
Applications
| Audio Pre-amplifier Stage | Industrial Level Shifter |
|---|---|
Use Scenario: Amplifying low-level microphone or sensor signals in battery-powered portable audio devices. IC Role / Device Role / Timing Role: PNP small-signal amplifier in common-emitter configuration with emitter degeneration for linearity. Use Value: Class C hFE ensures stable gain over temperature; −300 mV VCE(sat) preserves headroom in single-supply designs. |
Use Scenario: Translating logic-level signals between −5 V and −12 V domains in PLC I/O modules. IC Role / Device Role / Timing Role: Active pull-up switch in open-collector interface circuits with programmable threshold. Use Value: −65 V VCEO provides 10+ V safety margin; low Cob maintains signal integrity up to 10 MHz. |
| Relay Driver Circuit | Discrete Voltage Regulator Error Amplifier |
Use Scenario: Driving 12 V/24 V electromagnetic relays in HVAC control panels with microcontroller GPIO. IC Role / Device Role / Timing Role: Saturated PNP switch controlling relay coil current with base-current limiting. Use Value: −300 mV VCE(sat) minimizes power loss and self-heating; 500 mW PD supports continuous 100 mA coil drive. |
Use Scenario: Error amplification stage in linear regulators supplying precision analog subsystems. IC Role / Device Role / Timing Role: High-gain, low-drift differential pair component in feedback loop compensation network. Use Value: Tight hFE binning improves regulation accuracy; low noise figure prevents ripple injection into reference paths. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC557CTA | Lower VCEO (−45 V), same hFE Class C, identical TO-92-3 package | Suitable only for ≤−45 V rails; not interchangeable where −65 V margin is required | Select BC557CTA only when system voltage is capped at −45 V and cost optimization is prioritized. |
| MMBT5551 | NPN polarity, +160 V VCEO, 80–250 hFE, SOT-23 package | Requires circuit topology reversal; unsuitable for direct PNP replacement without redesign | Choose MMBT5551 only in new NPN-based designs needing higher voltage rating and surface-mount footprint. |
Compared with BC557CTA and MMBT5551, the BC556CTA uniquely delivers −65 V PNP switching capability in through-hole TO-92 with Class C gain binning - making it irreplaceable in legacy −48 V telecom and industrial control boards requiring proven reliability and exact form-fit-function.
Availability
BC556CTA is available at Aetrix Electronics and suitable for industrial control systems, audio signal conditioning circuits, and relay driver modules requiring stable component supply and long-term BOM continuity.
Supply support for BC556CTA 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, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The BC556CTA belongs to onsemi's legacy BC5xx family of general-purpose bipolar transistors, engineered for robustness, wide operating temperature range (−65 °C to +150 °C), and seamless complementarity with BC54x NPN counterparts in push-pull and differential designs.
FAQ
What is the maximum collector-emitter voltage rating for BC556CTA?
The BC556CTA has a maximum collector-emitter voltage (VCEO) rating of −65 V at 25 °C ambient. This rating applies under DC conditions with no secondary breakdown limitations, and must be derated per thermal constraints when junction temperature exceeds 25 °C. The BC556CTA is rated for sustained operation in −48 V systems with safety margin.
Is BC556CTA pin-compatible with BC557CTA or BC558CTA?
No - while BC556CTA, BC557CTA, and BC558CTA share the same TO-92-3 package and pinout (Collector-Base-Emitter), they differ in absolute maximum ratings: BC556CTA supports −65 V VCEO, whereas BC557CTA is rated for −45 V and BC558CTA for −30 V. Substitution requires verification of voltage stress margins in the target circuit.
What hFE range does BC556CTA provide, and how is it binned?
The BC556CTA is hFE Class C, guaranteeing a DC current gain range of 420 to 800 when measured at VCE = −5 V and IC = −2 mA. This binning is performed during final test and marked as "C" on the device body, ensuring predictable bias stability in amplifier and switching designs.
Does BC556CTA meet RoHS and environmental compliance standards?
Yes - BC556CTA is Pb-free, halogen-free/BFR-free, and fully RoHS-compliant per EU Directive 2011/65/EU. It is manufactured in onsemi's certified facilities and carries no substance-of-concern exemptions. The TO-92-3 package (Case 135AR) complies with JEDEC standards for lead finish and material content.
What is the thermal resistance (RθJA) of BC556CTA, and how does it affect layout?
The BC556CTA has a junction-to-ambient thermal resistance (RθJA) of 250 °C/W under standard FR-4 PCB conditions (76 mm × 114 mm, minimum land pattern). This means a 500 mW power dissipation causes a 125 °C junction rise above ambient - so PCB copper area, airflow, and ambient temperature must be managed to keep TJ ≤ 150 °C. The BC556CTA does not require heatsinking below ~250 mW in typical enclosures.
BC556CTA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Packaging:
- Tape & Box (TB)
- 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
BC556CTA FAQ
1.How can I place an order for BC556CTA through Aetrix?
Please submit a Request for Quotation (RFQ) for BC556CTA 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 BC556CTA reliable?
The price and inventory of BC556CTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC556CTA is usually 5 days.
3.What payment methods are accepted for BC556CTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC556CTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC556CTA?
BC556CTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC556CTA 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 BC556CTA?
For technical support, including BC556CTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC556CTA requirements.
6.How does Aetrix verify that BC556CTA is sourced from the original manufacturer or authorized distributors?
All BC556CTA 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 BC556CTA meets industry standards.
7.What is the process for return or replacement of BC556CTA?
All BC556CTA units undergo pre-shipment inspection (PSI). If there is an issue with BC556CTA, 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 BC556CTA part is unused and in its original packaging.
Return procedure for BC556CTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BC556CTA 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…
