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onsemi BDX53B
- Part No.:
- BDX53B
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-220-3
- Datasheet:
-
BDX53B.pdf
- Description:
- TRANS NPN DARL 80V 8A TO-220
- Quantity:
- Payment:
- Shipping:
Inventory:5,590
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Product details
Overview
BDX53B from onsemi is an NPN Darlington power transistor in TO-220 package, designed for medium-power linear amplification and low-speed switching. It delivers 8 A continuous collector current, sustains 80 Vdc collector-emitter voltage (VCEO(sus)), and exhibits typical DC current gain (hFE) of 2500 at 4.0 A - used in motor control drivers and relay interface circuits.
For engineers reviewing the BDX53B datasheet, pinout, applications, or equivalent options, key selection criteria include its built-in base-emitter shunt resistors, 2.0 Vdc max VCE(sat) at 3.0 A, thermal resistance RJC = 1.92 °C/W, and Pb-free RoHS-compliant TO-220 construction.
Technical Context
The BDX53B integrates two NPN transistors in monolithic Darlington configuration with internal base-emitter shunt resistors to ensure reliable turn-off. Its sustaining voltage rating (VCEO(sus) = 80 Vdc min at IC = 100 mAdc) reflects ruggedness under inductive load switching.
Thermal design is constrained by junction-to-case resistance (RJC = 1.92 °C/W) and total device dissipation of 65 W at TC = 25°C, derating linearly at 0.48 W/°C above ambient - requiring heatsink integration for sustained >10 W operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO(sus) | 80 Vdc minimum - defines maximum safe collector-emitter voltage during switching transients with IB = 0. |
| IC (continuous) | 8.0 Adc - supports high-current loads like solenoids and small DC motors without external current sharing. |
| hFE (typ) | 2500 @ IC = 4.0 Adc - enables low-base-drive requirements, reducing driver-stage complexity and power loss. |
| VCE(sat) (max) | 2.0 Vdc @ IC = 3.0 Adc, IB = 12 mAdc - limits conduction loss to ≤6 W at 3 A, critical for thermal management. |
| RJC | 1.92 °C/W - dictates minimum heatsink thermal resistance needed to maintain TJ ≤ 150°C at full power. |
| PD (TC = 25°C) | 65 W - maximum steady-state power dissipation achievable only with adequate case cooling. |
| Package | TO-220 (Case 221A) - industry-standard through-hole power package with electrically isolated collector tab. |
Pinout & Package
BDX53B uses the TO-220 package (Case 221A, Style 1), featuring a metal tab that is electrically connected to the collector and serves as a thermal interface. The plastic body provides electrical isolation between collector and mounting hardware when used with insulating washers.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control input node; requires ~12 mA drive at 3 A output for saturation - compatible with TTL/CMOS logic via series resistor. |
| 2 | Collector | Main high-current output path; internally tied to metal tab - must be thermally coupled to heatsink and electrically isolated if chassis-grounded. |
| 3 | Emitter | Power return node; connects to system ground or load return; carries full load current with minimal voltage drop. |
| 4 | Collector | Dual-collector configuration enhances current handling and thermal distribution across the die - improves reliability under pulse loads. |
Key Features
| Feature | Design Value |
|---|---|
| Monolithic Darlington structure | Integrates driver + output transistor on single die - eliminates interconnect parasitics and ensures matched thermal behavior. |
| Built-in base-emitter shunt resistors | Guarantees active turn-off even with open-base conditions - prevents unintended latch-up in relay or lamp driver applications. |
| High hFE (2500 typ) | Reduces required base drive current by >10× vs. single bipolar transistor - simplifies microcontroller GPIO interfacing. |
| Pb-free & RoHS compliant | Meets global environmental regulations without compromising thermal or electrical performance - suitable for industrial and consumer production. |
| TO-220 mechanical robustness | Rated for ≥10,000 thermal cycles and vibration tolerance per MIL-STD-202 - validated for automotive under-hood and industrial control environments. |
Applications
| DC Motor Driver Stage | Relay Interface Circuit |
|---|---|
Use Scenario: Driving 24 V, 5 A brushed DC motors in industrial actuators with PWM-controlled speed regulation. IC Role / Device Role / Timing Role: Main power switch in low-frequency (<1 kHz) H-bridge half-bridge stage - handles bidirectional current and inductive flyback energy. Use Value: 80 V VCEO(sus) withstands back-EMF spikes up to 60 V; 2.0 V VCE(sat) limits conduction loss to <10 W at full load, enabling compact heatsink design. |
Use Scenario: Controlling 12 V/24 V electromagnetic relays in PLC I/O modules where microcontroller GPIOs cannot source sufficient current. IC Role / Device Role / Timing Role: High-gain current amplifier translating 5 mA logic-level signals into 100–500 mA coil drive - operates in saturated switch mode. Use Value: Built-in base-emitter shunt resistor ensures relay de-energizes fully even during MCU reset or signal dropout - eliminates contact chatter. |
| Lamp Dimming Module | Linear Power Regulator Pass Element |
Use Scenario: Phase-angle dimming of incandescent lamps in commercial lighting controllers using triac-triggered gate drive. IC Role / Device Role / Timing Role: Low-speed switching element driving triac gate with isolated 10–20 mA pulses - operates at 100–120 Hz line frequency. Use Value: 8 A IC rating accommodates surge currents during cold filament turn-on; 80 V rating covers peak AC line transients up to 1.4 × 120 VAC. |
Use Scenario: Pass transistor in adjustable 0–30 V, 3 A linear bench power supply with analog feedback loop. IC Role / Device Role / Timing Role: Voltage-controlled current source operating in active region - dissipates up to 45 W continuously under worst-case dropout. Use Value: RJC = 1.92 °C/W allows stable operation with 2.5 K/W heatsink at 70°C ambient - avoids thermal runaway due to high hFE temperature stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN Darlington power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TIP122 | VCEO(sus) = 100 Vdc (min), hFE = 1000 (min) @ IC = 3 A - higher voltage rating but lower gain than BDX53B. | Better suited for 100 V bus systems; requires ~3× more base current for same collector current - increases driver complexity. | Choose TIP122 when VCEO margin >100 V is mandatory and base drive capability permits higher IB. |
| MJ11012 | VCEO(sus) = 100 Vdc (min), IC = 30 A (continuous), RJC = 1.3 °C/W - higher current/power capability in TO-3 package. | Requires larger heatsink and PCB real estate; not pin-compatible - needs layout revision and driver revalidation. | Select MJ11012 only for >15 A applications where BDX53B's 8 A limit is insufficient and TO-3 mounting is acceptable. |
Compared with TIP122 and MJ11012, the BDX53B offers optimal balance of gain, voltage rating, and TO-220 footprint for 5–8 A industrial switching - delivering lowest base drive burden while maintaining compatibility with standard power PCB layouts.
Availability
BDX53B is available at Aetrix Electronics and suitable for industrial motor control, relay interface, lamp dimming, and linear regulator applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.
Supply support for BDX53B 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 power management, analog, sensor, and discrete devices for automotive, industrial, and cloud power markets.
The BDX53B belongs to onsemi's plastic medium-power complementary silicon transistor family, engineered for rugged, cost-effective linear amplification and low-speed switching in harsh industrial environments.
FAQ
What is the maximum continuous collector current rating for the BDX53B?
The BDX53B is rated for 8.0 Adc continuous collector current at case temperature TC = 25°C. This rating assumes proper heatsinking; actual usable current decreases with rising TC due to 0.48 W/°C derating of its 65 W total dissipation capability. At TC = 75°C, maximum sustainable IC drops to approximately 5.6 A under steady-state conditions.
Does the BDX53B have built-in protection features?
Yes, the BDX53B incorporates monolithic base-emitter shunt resistors to ensure reliable turn-off under open-base or floating-input conditions - preventing unintended conduction in relay or lamp driver circuits. It does not include integrated overtemperature shutdown, avalanche ruggedness, or ESD protection beyond standard bipolar process limits.
Is the BDX53B pin-compatible with other devices in the BDX53/54 family?
The BDX53B shares identical TO-220 pinout (Style 1: Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter, Pin 4 = Collector) with BDX53C, BDX54B, and BDX54C. However, voltage and gain ratings differ: BDX53C has 100 V VCEO(sus) and higher hFE, while PNP counterparts (BDX54x) are complementary but not electrically interchangeable.
What is the typical DC current gain (hFE) of the BDX53B and at what conditions is it specified?
The BDX53B exhibits a typical hFE of 2500 at IC = 4.0 Adc and VCE = 3.0 Vdc, per onsemi datasheet Rev. 16. Minimum hFE is 750 under the same conditions. Gain remains usable down to IC = 100 mA and up to IC = 8.0 A, though it declines above 5 A due to internal emitter ballasting effects.
Can the BDX53B be used in linear regulator applications?
Yes, the BDX53B is suitable as a pass transistor in linear regulators, provided thermal design accounts for its RJC = 1.92 °C/W and maximum junction temperature of +150°C. For example, at 3 A output and 10 V dropout, it dissipates 30 W - requiring a heatsink with ≤3.2 °C/W thermal resistance to hold TC ≤ 50°C.
BDX53B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-3
- Packaging:
- Tube
- Product Status:
- Obsolete
- Transistor Type:
- NPN - Darlington
- Current - Collector (Ic) (Max):
- 8 A
- Voltage - Collector Emitter Breakdown (Max):
- 80 V
- Vce Saturation (Max) @ Ib, Ic:
- 2V @ 12mA, 3A
- Current - Collector Cutoff (Max):
- 500µA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 750 @ 3A, 3V
- Power - Max:
- 65 W
- Frequency - Transition:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220
BDX53B FAQ
1.How can I place an order for BDX53B through Aetrix?
Please submit a Request for Quotation (RFQ) for BDX53B 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 BDX53B reliable?
The price and inventory of BDX53B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BDX53B is usually 5 days.
3.What payment methods are accepted for BDX53B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BDX53B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BDX53B?
BDX53B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BDX53B 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 BDX53B?
For technical support, including BDX53B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BDX53B requirements.
6.How does Aetrix verify that BDX53B is sourced from the original manufacturer or authorized distributors?
All BDX53B 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 BDX53B meets industry standards.
7.What is the process for return or replacement of BDX53B?
All BDX53B units undergo pre-shipment inspection (PSI). If there is an issue with BDX53B, 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 BDX53B part is unused and in its original packaging.
Return procedure for BDX53B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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