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onsemi SS8550CTA
- Part No.:
- SS8550CTA
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
SS8550CTA.pdf
- Description:
- TRANS PNP 25V 1.5A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:45,703
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Product details
Overview
SS8550CTA from onsemi is a PNP epitaxial silicon transistor in TO-92-3 (case 135AR) package, rated for −1.5 A collector current, −25 V collector-emitter breakdown voltage, and 1 W power dissipation at 25°C. It serves as a medium-power general-purpose amplifier or switch in portable audio output stages, complementary to SS8050 NPN transistors.
For engineers reviewing the SS8550CTA datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed hFE range (120–200 at IC = −100 mA), low VCE(sat) of −0.28 V (typ.) at IC/IB = 10, RoHS-compliant Pb-free construction, and thermal resistance of 125°C/W in standard FR-4 PCB layout.
Technical Context
This discrete PNP bipolar junction transistor operates in linear amplification or saturated switching modes. Its DC current gain (hFE) is classified as "C" grade (120–200 at VCE = −1 V, IC = −100 mA), and it delivers fT ≥ 100 MHz under VCE = −10 V, IC = −50 mA conditions.
Designed for Class B push-pull audio amplifier output stages in portable radios, it features low saturation voltages (VCE(sat) ≤ −0.50 V, VBE(sat) ≤ −1.20 V at IC = −800 mA/IB = −80 mA) and tight leakage control (ICBO ≤ −100 nA at VCB = −35 V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Collector Current (IC) | −1.5 A maximum - supports medium-current switching and amplification up to 1.5 A pulsed load. |
| VCEO | −25 V - defines safe operating voltage between collector and emitter with base open. |
| hFE (C grade) | 120–200 at IC = −100 mA - ensures predictable current amplification in bias-critical linear circuits. |
| VCE(sat) | −0.28 V (typ.) at IC = −800 mA, IB = −80 mA - minimizes conduction loss in saturated-switch applications. |
| fT | ≥100 MHz - enables use in audio-frequency amplifiers and low-MHz switching circuits. |
| RJA | 125°C/W - requires minimum PCB copper area (76 mm × 114 mm FR-4) for full 1 W power dissipation. |
| Cob | 15 pF at VCB = −10 V - limits high-frequency feedback and affects stability in RF-adjacent designs. |
Pinout & Package
SS8550CTA uses the TO-92-3 package (case 135AR), lead-formed variant with standardized 4.83 mm × 4.76 mm footprint and through-hole mounting. Pin identification follows JEDEC TO-92 orientation: flat side facing viewer, leads down, left-to-right = Emitter (1), Base (2), Collector (3).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current source terminal for PNP device | Connected to higher potential rail in common-emitter switch; sets reference for base drive polarity. |
| 2 (Base) | Control input for minority-carrier injection | Receives negative-going current to turn on; requires series resistor to limit IB per hFE and VBE(sat) specs. |
| 3 (Collector) | Current sink terminal | Drives load to ground or lower potential; must withstand reverse-biased VCEO stress during off-state. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free, Halogen-free, RoHS-compliant | Meets global environmental compliance without derating or process change for lead-free assembly. |
| Complementary pairing with SS8050 | Enables matched push-pull output stages with symmetric gain, saturation, and thermal behavior. |
| Guaranteed hFE classification (C grade) | Ensures consistent DC biasing across production lots for stable amplifier quiescent points. |
| Low VCE(sat) and VBE(sat) | Reduces conduction losses and improves efficiency in battery-powered switching applications. |
Applications
| Portable AM/FM Radio Output Stage | DC Motor Driver (Small Load) |
|---|---|
Use Scenario: Final audio amplification stage driving 8 Ω speaker in handheld radio. IC Role / Device Role / Timing Role: PNP switch in Class B push-pull pair with SS8050, delivering peak current up to −1.5 A. Use Value: Low VCE(sat) (−0.28 V typ.) preserves battery voltage headroom; hFE consistency ensures symmetrical crossover distortion control. | Use Scenario: H-bridge half-bridge leg controlling bidirectional 12 V, 500 mA DC motor. IC Role / Device Role / Timing Role: High-side PNP switch enabling current sourcing to motor winding when paired with NPN low-side driver. Use Value: −25 V VCEO rating accommodates inductive kickback; 15 pF Cob limits unintended turn-on during fast switching transitions. |
| LED Constant-Current Sink | Linear Voltage Regulator Pass Element |
Use Scenario: Precision current sink for high-brightness white LED string in emergency lighting. IC Role / Device Role / Timing Role: Adjustable emitter-follower current regulator with feedback resistor network. Use Value: Tight hFE tolerance (120–200) enables ±5% current accuracy without trimming; −1.5 A IC rating supports multi-LED arrays. | Use Scenario: Series pass transistor in 5 V, 800 mA linear regulator for noise-sensitive analog subsystems. IC Role / Device Role / Timing Role: PNP-based adjustable LDO pass element with external voltage reference and error amplifier. Use Value: 1 W PD rating allows operation at 1.5 V dropout (e.g., 6.5 V input → 5 V out @ 800 mA) with adequate heatsinking. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PNP transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SS8550CBU | Same die, TO-92-3 case 135AN (non-lead-formed); 10,000 units/bulk box | No mechanical difference in electrical function; differs only in packaging format and reel vs. bulk delivery | Select SS8550CBU for high-volume automated placement requiring bulk packaging. |
| MMBT8550DW | SOT-323 package, dual-die configuration, lower PD (0.35 W), hFE 100–300 (D grade) | Not pin-compatible; surface-mount only; unsuitable for >350 mA continuous loads due to thermal limits | Choose MMBT8550DW only for space-constrained PCBs where power demand is ≤350 mA and SMT assembly is mandatory. |
Compared with SS8550CBU, SS8550CTA offers identical electrical performance but optimized lead-forming for manual or semi-automated through-hole insertion; versus MMBT8550DW, SS8550CTA provides 2.9× higher power handling and proven suitability for audio output and motor drive roles requiring robust thermal margin.
Availability
SS8550CTA is available at Aetrix Electronics and suitable for portable audio amplifiers, small DC motor controls, LED current regulation, and linear voltage regulation requiring stable component supply and RoHS-compliant through-hole transistors.
Supply support for SS8550CTA 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 focused on energy-efficient electronics, with leadership in automotive, industrial, cloud, and IoT power and sensing solutions.
The SS8550 series belongs to onsemi's general-purpose bipolar transistor product line, engineered for cost-sensitive, medium-power analog and switching applications in consumer and industrial equipment.
FAQ
What is the pin configuration of SS8550CTA?
The SS8550CTA uses a standard TO-92-3 package with leads arranged left-to-right (flat side facing viewer, leads down) as Emitter (1), Base (2), Collector (3). This matches JEDEC TO-92 orientation and is confirmed in the onsemi datasheet mechanical drawings for case 135AR. The SS8550CTA pinout is identical to SS8550CBU and other SS8550 variants.
Is SS8550CTA RoHS compliant and lead-free?
Yes, SS8550CTA is explicitly marked Pb-free, halogen-free/BFR-free, and RoHS compliant per the onsemi datasheet revision 3 (August 2021). It meets EU RoHS Directive 2011/65/EU and is suitable for lead-free reflow soldering processes without derating.
What is the hFE classification for SS8550CTA?
The SS8550CTA is classified as "C" grade, with hFE ranging from 120 to 200 when measured at VCE = −1 V and IC = −100 mA. This classification is specified in the onsemi datasheet's hFE Classification table and applies to all SS8550C-marked variants including SS8550CTA.
Can SS8550CTA replace SS8550DTA in a design?
No - SS8550CTA and SS8550DTA differ in hFE grading: C grade (120–200) vs. D grade (160–300). While electrically interchangeable in many circuits, bias point shifts may occur in precision linear amplifiers. SS8550CTA is not a drop-in replacement for SS8550DTA unless hFE tolerance is verified in the target application.
What is the maximum power dissipation for SS8550CTA at 70°C ambient?
At TA = 70°C, SS8550CTA's maximum power dissipation is 0.6 W. This is calculated using the datasheet's 8 mW/°C derating factor: PD = 1 W − (8 mW/°C × (70 − 25)°C) = 1 W − 0.36 W = 0.64 W, rounded conservatively to 0.6 W for design margin. Full 1 W operation requires TA ≤ 25°C with specified PCB layout.
SS8550CTA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Packaging:
- Cut Tape (CT)
- Product Status:
- Active
- Transistor Type:
- PNP
- Current - Collector (Ic) (Max):
- 1.5 A
- Voltage - Collector Emitter Breakdown (Max):
- 25 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 80mA, 800mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 120 @ 100mA, 1V
- Power - Max:
- 1 W
- Frequency - Transition:
- 200MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
SS8550CTA FAQ
1.How can I place an order for SS8550CTA through Aetrix?
Please submit a Request for Quotation (RFQ) for SS8550CTA 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 SS8550CTA reliable?
The price and inventory of SS8550CTA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SS8550CTA is usually 5 days.
3.What payment methods are accepted for SS8550CTA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SS8550CTA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SS8550CTA?
SS8550CTA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SS8550CTA 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 SS8550CTA?
For technical support, including SS8550CTA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SS8550CTA requirements.
6.How does Aetrix verify that SS8550CTA is sourced from the original manufacturer or authorized distributors?
All SS8550CTA 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 SS8550CTA meets industry standards.
7.What is the process for return or replacement of SS8550CTA?
All SS8550CTA units undergo pre-shipment inspection (PSI). If there is an issue with SS8550CTA, 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 SS8550CTA part is unused and in its original packaging.
Return procedure for SS8550CTA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SS8550CTA Tags
-
MMBT3906LT1G
onsemi
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MMBT3904-7-F
Diodes Incorporated
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MMBT3904LT1G
onsemi
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MMBT3906-7-F
Diodes Incorporated
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MMBT3904-TP
Micro Commercial Co
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MMBT2222A-7-F
Diodes Incorporated
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BC846BLT1G
onsemi
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BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
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MMBT2222A-TP
Micro Commercial Co
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MMBTA06LT1G
onsemi
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MMBT2222ALT1G
onsemi
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