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NXP Semiconductors BC635,112
- Part No.:
- BC635,112
- Manufacturer:
- NXP Semiconductors
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Datasheet:
-
BC635,112.pdf
- Description:
- TRANS NPN 45V 1A TO-92-3
- Quantity:
- Payment:
- Shipping:
Inventory:5,058
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Product details
Overview
BC635,112 from NXP Semiconductors is a 45 V, 1 A NPN medium power transistor in SOT54A (SC-43A/TO-92) package, designed for linear voltage regulation, low-side switching, and MOSFET gate driving. It delivers DC current gain (hFE) of 63–250 at IC = 150 mA, VCE = 2 V, with two hFE selections (-10 and -16), and supports peak collector current up to 1.5 A.
For engineers reviewing the BC635,112 datasheet, BC635,112 pinout, BC635,112 application, or BC635,112 equivalent, this page provides verified pin configuration, thermal derating behavior on FR4 PCB, hFE selection guidance, and validated alternatives for discrete power control circuits.
Technical Context
The BC635,112 operates as a silicon NPN bipolar junction transistor optimized for medium-power linear and switching applications. Its structure supports continuous collector current up to 1 A and peak pulses to 1.5 A, with VCEO and VCBO rated at 45 V and VEBO at 5 V - enabling use in 24 V industrial supplies and 3.3–12 V logic-level driver stages.
Thermal performance is defined for standard FR4 PCB mounting: Rth(j-a) = 150 K/W (standard footprint), Rth(j-sp) = 40 K/W, and Ptot = 0.83 W at Tamb ≤ 25 °C. The device exhibits fT = 100–180 MHz and Cc = 6 pF, confirming suitability for audio-frequency amplification and moderate-speed switching.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - maximum safe collector-emitter voltage with base open; defines rail compatibility up to 36 V DC systems. |
| IC | 1 A - continuous collector current rating; supports load switching up to ~12 W at 12 V with adequate heatsinking. |
| hFE (IC = 150 mA) | 63–250 - wide DC current gain range enables flexible bias design; -16 variant (100–250) improves drive efficiency in low-IB gate drivers. |
| VCEsat (IC = 500 mA) | ≤500 mV - low saturation voltage reduces conduction loss in linear regulators and switch-mode drivers. |
| fT | 100–180 MHz - transition frequency confirms stable operation in audio amplifiers and sub-MHz switching circuits. |
| Ptot (Tamb ≤ 25 °C) | 0.83 W - total power dissipation limit on standard FR4 PCB; requires thermal derating above 25 °C per Fig 1. |
| Rth(j-a) | 150 K/W - junction-to-ambient thermal resistance on standard single-sided FR4; informs heatsink-free ambient temperature margin. |
Pinout & Package
BC635,112 is supplied in SOT54A package (JEITA SC-43A, JEDEC TO-92), a through-hole plastic single-ended leaded 3-lead package with standardized pin spacing and mechanical dimensions per Fig 15. Mounting uses standard FR4 PCB with tin-plated copper.
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control terminal; accepts ~50 mA peak base current (IBM ≤ 0.2 A) to saturate 1 A collector current. |
| 2 | Collector | High-current output node; electrically connected to case in TO-92 outline; requires clearance for voltage isolation. |
| 3 | Emitter | Reference terminal; tied to ground or low-side return path; establishes common reference for bias and load current sensing. |
Key Features
| Feature | Design Value |
|---|---|
| High current capability | 1 A continuous / 1.5 A pulsed collector current enables direct drive of relays, LEDs, and small solenoids without external buffers. |
| Two hFE selections | hFE-10 (63–160) and hFE-16 (100–250) allow precise gain matching across production batches for consistent bias stability in regulator feedback loops. |
| High power dissipation | 0.83 W on standard FR4 PCB supports linear operation at >500 mW without forced airflow or heatsinks in compact industrial modules. |
| Low VCEsat | ≤500 mV at IC = 500 mA / IB = 50 mA minimizes dropout voltage in series pass transistors and reduces heat generation in driver stages. |
| Robust voltage ratings | 45 V VCEO and VCBO, plus 5 V VEBO, ensure reliable operation in 24 V automotive auxiliary circuits and 36 V industrial power rails. |
Applications
| Linear Voltage Regulators | Low-Side Switches |
|---|---|
Use Scenario: Used as series pass element in adjustable 3-terminal linear regulators delivering 1–1.5 A at 3.3–12 V output. IC Role / Device Role / Timing Role: NPN medium power transistor operating in active region to regulate output voltage via feedback-controlled base current. Use Value: Low VCEsat (≤500 mV) maintains <1 V dropout at full load, while hFE-16 selection ensures stable loop gain with minimal base drive overhead. |
Use Scenario: Controls ground-return paths for 12 V DC loads such as fans, indicators, and sensors in PLC I/O modules. IC Role / Device Role / Timing Role: NPN switch biased into saturation to minimize on-state resistance and power loss during steady-state conduction. Use Value: 1 A continuous rating and 1.5 A pulse capability support transient inrush currents; TO-92 package allows direct through-hole mounting on control boards. |
| MOSFET Drivers | Amplifiers |
Use Scenario: Drives the gate of N-channel power MOSFETs in half-bridge motor control stages where logic-level microcontrollers lack sufficient sink current. IC Role / Device Role / Timing Role: Low-side NPN buffer providing fast turn-on/turn-off current to charge/discharge MOSFET gate capacitance. Use Value: fT ≥ 100 MHz and Cc = 6 pF enable sub-100 ns switching transitions; hFE-16 variant reduces required MCU GPIO drive strength by >2×. |
Use Scenario: Audio preamplifier stage in industrial instrumentation requiring low-noise, high-linearity gain at frequencies up to 20 kHz. IC Role / Device Role / Timing Role: Common-emitter amplifier configured with emitter degeneration for stable DC bias and AC signal amplification. Use Value: hFE consistency (63–250) and low ICBO (<100 nA at 25 °C) preserve gain accuracy and offset stability over temperature and time. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN medium power transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC636,112 | PNP complement with identical VCEO (45 V), IC (1 A), and SOT54A package; hFE range 63–250 but inverted polarity. | Used in complementary emitter-follower or push-pull output stages where sourcing (not sinking) current is required. | Select BC636,112 only when circuit topology demands PNP functionality - not a drop-in replacement for BC635,112. |
| BCX54,115 | SOT89 surface-mount package; higher thermal performance (Ptot = 0.85 W with 1 cm² pad); same VCEO/IC/hFE specs but different pinout (emitter-collector-base). | Preferred in space-constrained, thermally demanding designs where reflow assembly and improved heatsinking are available. | Choose BCX54,115 for SMT production and better thermal management; requires PCB layout change due to 3-pin SOT89 pinout reversal. |
Compared with BC635,112, BC636,112 provides complementary PNP functionality in identical packaging but cannot substitute in NPN-biased circuits, while BCX54,115 offers superior thermal handling in SMT form but mandates pinout redesign and eliminates through-hole assembly compatibility.
Availability
BC635,112 is available at Aetrix Electronics and suitable for linear voltage regulators, low-side switches, and MOSFET drivers requiring stable component supply in industrial control, power management, and embedded analog subsystems.
Supply support for BC635,112 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
NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in high-performance analog, logic, and power discrete solutions for industrial, automotive, and consumer markets.
The BC635,112 belongs to NXP's legacy medium-power bipolar transistor family, engineered for reliability in linear regulation, switching, and driver applications where cost-effective through-hole discretes remain essential.
FAQ
What is the package type and marking code for BC635,112?
The BC635,112 is packaged in SOT54A (JEITA SC-43A / JEDEC TO-92) and marked with "C635" on the device body. This through-hole 3-lead package features standardized lead spacing and mechanical dimensions per NXP's Fig 15, supporting manual or wave-solder assembly.
Does BC635,112 have multiple hFE gain options, and how are they distinguished?
Yes, BC635,112 is available in two hFE selections: -10 (63–160) and -16 (100–250), both specified at VCE = 2 V and IC = 150 mA. The -16 variant is identified by marking "C63516", while standard BC635,112 carries "C635". Gain selection impacts base drive requirements in precision regulator and driver designs.
What is the maximum power dissipation of BC635,112 on a standard FR4 PCB?
The BC635,112 has a total power dissipation (Ptot) of 0.83 W when mounted on a standard FR4 PCB with single-sided copper and tin plating at Tamb ≤ 25 °C. Power must be derated linearly above 25 °C per the curve in Fig 1, reaching zero at ~107 °C ambient.
Can BC635,112 be used in place of BC636,112?
No - BC635,112 is an NPN transistor, while BC636,112 is its PNP complement. They share identical voltage/current ratings and SOT54A packaging but opposite polarity and biasing requirements. Substituting one for the other will result in circuit failure unless topology is redesigned.
What are the absolute maximum ratings for BC635,112?
The absolute maximum ratings for BC635,112 include VCEO = 45 V, VCBO = 45 V, VEBO = 5 V, IC = 1 A, ICM = 1.5 A (tp ≤ 1 ms), IBM = 0.2 A (tp ≤ 1 ms), and Tj = 150 °C. Exceeding any of these may cause permanent damage; operation should remain within characteristics limits in Table 8.
BC635,112 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 (TO-226AA) Formed Leads
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 1 A
- Voltage - Collector Emitter Breakdown (Max):
- 45 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 50mA, 500mA
- Current - Collector Cutoff (Max):
- 100nA (ICBO)
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 63 @ 150mA, 2V
- Power - Max:
- 830 mW
- Frequency - Transition:
- 180MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92-3
BC635,112 FAQ
1.How can I place an order for BC635,112 through Aetrix?
Please submit a Request for Quotation (RFQ) for BC635,112 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 BC635,112 reliable?
The price and inventory of BC635,112 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC635,112 is usually 5 days.
3.What payment methods are accepted for BC635,112?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC635,112 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC635,112?
BC635,112 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC635,112 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 BC635,112?
For technical support, including BC635,112 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC635,112 requirements.
6.How does Aetrix verify that BC635,112 is sourced from the original manufacturer or authorized distributors?
All BC635,112 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 BC635,112 meets industry standards.
7.What is the process for return or replacement of BC635,112?
All BC635,112 units undergo pre-shipment inspection (PSI). If there is an issue with BC635,112, 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 BC635,112 part is unused and in its original packaging.
Return procedure for BC635,112:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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