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onsemi BC635ZL1G
- Part No.:
- BC635ZL1G
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Datasheet:
-
BC635ZL1G.pdf
- Description:
- TRANS NPN 45V 1A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:5,375
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Product details
Overview
BC635ZL1G from onsemi is an NPN silicon high-current transistor in TO-92 package, rated for VCEO = 45 V, IC = 1.0 A, PD = 625 mW at TA = 25°C, with hFE = 25–250 (IC = 5–500 mA), used in linear power regulation and low-frequency switching circuits.
For engineers reviewing the BC635ZL1G datasheet, pinout, applications, or equivalent options, key selection criteria include its 45 V VCEO, 1.0 A continuous collector current, TO-92 thermal resistance (RJA = 200 °C/W), Pb-free compliance, and verified hFE performance across 5–500 mA operating range.
Technical Context
The BC635ZL1G operates as a general-purpose NPN bipolar junction transistor optimized for medium-power amplification and switching. Its design supports DC current gain (hFE) of ≥25 at IC = 5 mA and ≥40 at IC = 150 mA, with VCE(sat) ≤ 0.5 V at IC = 500 mA / IB = 50 mA.
Thermal performance is defined by RJA = 200 °C/W and RJC = 83.3 °C/W, enabling operation from −55°C to +150°C. It exhibits fT = 200 MHz at IC = 50 mA, VCE = 2 V, confirming suitability for audio-frequency and low-speed digital switching-not RF or high-speed logic.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 45 V - Maximum safe collector-emitter voltage before breakdown under open-base condition. |
| IC (continuous) | 1.0 A - Continuous collector current rating at TA = 25°C; derates 5.0 mW/°C above ambient. |
| hFE | 25–250 - DC current gain range across 5–500 mA collector current, enabling predictable biasing in amplifier stages. |
| VCE(sat) | ≤0.5 V - Low saturation voltage at IC = 500 mA / IB = 50 mA, minimizing conduction loss in switch-mode applications. |
| fT | 200 MHz - Current-gain bandwidth product at IC = 50 mA, limiting usable frequency to audio and sub-MHz switching. |
| RJA | 200 °C/W - Junction-to-ambient thermal resistance in free-air, defining heatsinking requirements for sustained 1 A operation. |
Pinout & Package
BC635ZL1G uses the TO-92 (Case 29, Style 14) plastic package with 3 leads, standardized leadform for through-hole mounting and manual prototyping. Package dimensions comply with ANSI Y14.5M and are fully specified in ON Semiconductor's BC635/D datasheet, page 5.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Emitter | Current exit path; referenced to ground in common-emitter configurations; requires low-impedance return path for stable biasing. |
| 2 | Collector | Current entry path; connected to load or supply rail; must withstand 45 V and dissipate up to 625 mW at ambient. |
| 3 | Base | Control terminal; drives transistor into active/saturation via ~50 mA base current for full 500 mA collector conduction. |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free TO-92 package | Complies with RoHS Directive 2011/65/EU; suitable for lead-free reflow and hand-soldering processes without contamination risk. |
| High hFE consistency | Guaranteed hFE ≥25 at low current (5 mA) and ≥40 at mid-current (150 mA), simplifying bias network design across production lots. |
| Robust thermal capability | Rated for TJ = −55°C to +150°C; enables use in automotive under-hood and industrial control environments with minimal derating. |
| Low VBE(on) | ≤1.0 V at IC = 500 mA, reducing base drive power and easing compatibility with 3.3 V or 5 V microcontroller GPIO outputs. |
Applications
| Linear Power Regulators | DC Motor Drivers (Small) |
|---|---|
Use Scenario: Used as pass transistor in adjustable linear regulators (e.g., LM317-based circuits) delivering up to 1 A output current. IC Role / Device Role / Timing Role: NPN pass element controlling output voltage via base bias; operates in active region for precise voltage control. Use Value: Delivers stable 1 A output with <0.5 V dropout at full load due to low VCE(sat) and high hFE. | Use Scenario: Drives brushed DC motors in consumer appliances (e.g., fans, pumps) requiring <1 A stall current. IC Role / Device Role / Timing Role: Single-stage NPN switch controlled by MCU GPIO; configured in common-emitter with flyback diode protection. Use Value: Enables reliable on/off control with <1.0 V base drive requirement and thermal margin up to +125°C ambient. |
| Audio Amplifier Stages | Relay Drivers |
Use Scenario: Serves as pre-driver or output stage in Class-A/B audio amplifiers for portable speakers and intercom systems. IC Role / Device Role / Timing Role: Voltage/current amplifier in emitter-follower or common-emitter topology; biased for low-distortion linearity. Use Value: Supports 20 Hz–20 kHz signal fidelity with fT = 200 MHz and hFE stability across audio current range. | Use Scenario: Activates electromechanical relays (e.g., 5 V, 100–500 mW coils) in PLC I/O modules and HVAC controllers. IC Role / Device Role / Timing Role: High-gain switch providing >10× current gain to drive relay coil from low-power logic signals. Use Value: Ensures robust relay pull-in with guaranteed hFE ≥40 at 150 mA, eliminating need for Darlington pairing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BC635RL1G | Same electrical specs and TO-92 Pb-free package; differs only in tape-and-reel packaging (2000 pcs vs. BC635ZL1G's 2000 pcs ammo box). | No functional difference; identical use in PCB assembly-only logistics variation. | Select BC635RL1G for automated pick-and-place; BC635ZL1G for manual or semi-automated insertion where ammo box handling is preferred. |
| BC637ZL1G | Higher VCEO = 60 V and VCBO = 60 V; otherwise identical TO-92 Pb-free construction, hFE, and thermal specs. | Enables use in 48 V nominal systems (e.g., telecom power supplies) where BC635ZL1G's 45 V rating is marginal. | Choose BC637ZL1G when system transient voltages exceed 45 V; no layout or bias changes required. |
Compared with BC635ZL1G, BC635RL1G offers identical performance in tape-and-reel format for SMT lines, while BC637ZL1G provides 15 V higher breakdown margin-critical for 48 V bus designs-without altering footprint or drive requirements.
Availability
BC635ZL1G is available at Aetrix Electronics and suitable for linear power regulators, small DC motor drivers, audio amplifier stages, and relay drivers requiring stable component supply and RoHS-compliant sourcing.
Supply support for BC635ZL1G 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, sensors, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The BC635ZL1G belongs to onsemi's legacy high-current NPN transistor family designed for cost-sensitive, medium-power linear and switching applications where reliability, thermal robustness, and Pb-free compliance are essential.
FAQ
What is the maximum collector-emitter voltage rating for BC635ZL1G?
The BC635ZL1G has a maximum collector-emitter voltage (VCEO) rating of 45 Vdc, tested under open-base conditions with IC = 10 Adc. This rating defines the absolute upper limit before avalanche breakdown occurs and must not be exceeded in circuit design-even transiently-without appropriate clamping or derating.
Is BC635ZL1G RoHS compliant and what does the 'G' suffix indicate?
Yes, BC635ZL1G is RoHS compliant. The 'G' suffix explicitly denotes a Pb-free (lead-free) variant per ON Semiconductor's packaging standard, confirmed in the device ordering table on page 4 of the BC635/D datasheet. It uses matte tin lead plating and meets JEDEC J-STD-609A Class 1 requirements.
What is the DC current gain (hFE) range of BC635ZL1G and how does it vary with operating conditions?
The BC635ZL1G exhibits hFE = 25–100 at IC = 5.0 mAdc and VCE = 2.0 Vdc, and hFE = 40–250 at IC = 150 mAdc and VCE = 2.0 Vdc. This wide spread reflects process variation and confirms the need for design margin-especially in bias networks where minimum hFE = 25 must guarantee intended operation.
Can BC635ZL1G be used in switching applications, and what is its saturation voltage?
Yes, BC635ZL1G is suitable for low-frequency switching (≤100 kHz). Its VCE(sat) is guaranteed ≤0.5 V at IC = 500 mAdc and IB = 50 mAdc, ensuring low conduction loss. However, its fT = 200 MHz does not imply high-speed switching capability-the device's storage time and fall time limit practical use to audio and power-control frequencies.
What is the thermal resistance and maximum junction temperature of BC635ZL1G?
The BC635ZL1G has a junction-to-ambient thermal resistance (RJA) of 200 °C/W and a junction-to-case value (RJC) of 83.3 °C/W. Its operating junction temperature range is −55°C to +150°C. At 1.0 A collector current, self-heating exceeds safe limits without heatsinking-designers must verify TJ using actual board layout and ambient conditions.
BC635ZL1G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Packaging:
- Tape & Box (TB)
- 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:
- 40 @ 150mA, 2V
- Power - Max:
- 625 mW
- Frequency - Transition:
- 200MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92 (TO-226)
BC635ZL1G FAQ
1.How can I place an order for BC635ZL1G through Aetrix?
Please submit a Request for Quotation (RFQ) for BC635ZL1G 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 BC635ZL1G reliable?
The price and inventory of BC635ZL1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC635ZL1G is usually 5 days.
3.What payment methods are accepted for BC635ZL1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC635ZL1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BC635ZL1G?
BC635ZL1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BC635ZL1G 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 BC635ZL1G?
For technical support, including BC635ZL1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC635ZL1G requirements.
6.How does Aetrix verify that BC635ZL1G is sourced from the original manufacturer or authorized distributors?
All BC635ZL1G 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 BC635ZL1G meets industry standards.
7.What is the process for return or replacement of BC635ZL1G?
All BC635ZL1G units undergo pre-shipment inspection (PSI). If there is an issue with BC635ZL1G, 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 BC635ZL1G part is unused and in its original packaging.
Return procedure for BC635ZL1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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