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onsemi BF422ZL1G
- Part No.:
- BF422ZL1G
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Datasheet:
-
BF422ZL1G.pdf
- Description:
- TRANS NPN 250V 0.05A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:3,059
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Product details
Overview
BF422ZL1G from onsemi is an NPN silicon high-voltage transistor designed for switching and amplification in off-line power supplies, horizontal deflection circuits, and pulse applications. It features VCEO = 250 V, IC = 50 mA continuous, hFE ≥ 50 at 25 mA/20 V, fT = 60 MHz, and TO-92 package with Pb-free construction.
For engineers reviewing the BF422ZL1G datasheet, pinout, applications, or equivalent options, key selection criteria include high-voltage breakdown capability, low saturation voltage (VCE(sat) ≤ 0.5 V), thermal resistance (RJA = 150 °C/W), and compatibility with legacy TO-92 PCB footprints in CRT flyback and industrial control designs.
Technical Context
This device operates as a medium-speed, high-voltage NPN switch optimized for stable gain and low leakage across −55°C to +150°C junction temperature. Its V(BR)CEO = 250 V and V(BR)CBO = 250 V support operation in 200–240 V AC line-derived circuits with margin.
The BF422ZL1G delivers hFE ≥ 50 at IC = 25 mA/VCE = 20 V and maintains VBE(sat) ≤ 2.0 V at IC/IB = 10, enabling efficient base drive in discrete SMPS gate drivers and pulse transformers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 250 Vdc - supports operation in 240 V AC mains-derived circuits with safety margin |
| IC (continuous) | 50 mAdc - suitable for low-to-medium power switching stages up to ~1.25 W dissipation |
| hFE | ≥50 at 25 mA/20 V - ensures reliable current amplification in linear and saturated switching modes |
| fT | 60 MHz - enables use in horizontal deflection and fast-pulse generator applications |
| VCE(sat) | ≤0.5 V at 20 mA/2 mA - reduces conduction loss and self-heating in repetitive switching |
| RJA | 150 °C/W - requires minimal copper area (200 mm² 1 oz Cu) for thermal management |
| Cre | ≤1.6 pF at 30 V - minimizes Miller effect in high-frequency switching nodes |
Pinout & Package
BF422ZL1G is housed in a Pb-free TO-92 package (Case 29, Style 14), with standardized lead configuration and 2000-unit ammo pack packaging.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Emitter | Current sink node; connected to ground or low-side return path in common-emitter switches |
| 2 | Collector | High-voltage output node; rated for 250 V blocking and 50 mA continuous conduction |
| 3 | Base | Control input; requires ≤2.0 V drive for full saturation at IC/IB = 10 |
Key Features
| Feature | Design Value |
|---|---|
| High VCEO rating | 250 V - enables direct use in 230 V AC line-synchronized circuits without intermediate voltage reduction |
| Pb-free TO-92 package | RoHS-compliant construction with standard footprint - supports automated assembly and legacy board reuse |
| Low VCE(sat) | ≤0.5 V - reduces power loss and thermal stress in high-duty-cycle switching applications |
| Stable hFE over temperature | Specified at −55°C, 25°C, and +125°C - ensures predictable gain in automotive and industrial environments |
| Low Cre | ≤1.6 pF - limits capacitive coupling and improves switching speed in high-frequency pulse circuits |
Applications
| Horizontal Deflection Circuits | Off-Line SMPS Switching |
|---|---|
Use Scenario: Horizontal output stage in CRT-based monitors and TVs operating at ~15.7 kHz with flyback energy recovery. IC Role / Device Role / Timing Role: High-voltage NPN switch controlling primary current in line-output transformer (LOPT). Use Value: 250 V VCEO and 60 MHz fT ensure safe retrace timing and minimal switching distortion. |
Use Scenario: Primary-side switching transistor in low-power AC/DC adapters (<10 W) with universal input (85–265 V AC). IC Role / Device Role / Timing Role: Discrete power switch in self-oscillating or fixed-frequency flyback converters. Use Value: Low VCE(sat) and stable hFE reduce conduction loss and improve efficiency at light loads. |
| Pulse Generators | Industrial Control Interfaces |
Use Scenario: Fast-rise-time pulse driver for optocoupler inputs, solenoid triggers, or logic-level translation in PLC I/O modules. IC Role / Device Role / Timing Role: Medium-speed digital switch translating TTL/CMOS signals to 100–200 V pulses. Use Value: 60 MHz fT and ≤1.6 pF Cre enable sub-100 ns rise/fall times with minimal overshoot. |
Use Scenario: Isolated feedback or signal conditioning stage in motor drive gate driver boards and HVAC control units. IC Role / Device Role / Timing Role: High-voltage level shifter or current amplifier interfacing microcontrollers to 200 V bus monitoring circuits. Use Value: 250 V V(BR)CBO and −55°C to +150°C TJ range support robust operation in harsh industrial enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage NPN transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BF422G | Same die, identical electrical specs; differs only in packaging (bulk box vs. ammo pack) | No functional difference - used interchangeably where packaging format is not constrained | Select BF422G for high-volume manual or semi-automated assembly requiring bulk handling |
| MPSA42 | VCEO = 300 V, hFE = 40–120 (min/max), RJA = 200 °C/W - higher voltage but lower thermal performance | Better suited for 300 V applications; less ideal for thermally constrained layouts due to higher RJA | Choose MPSA42 when >250 V blocking is required and board space allows larger thermal relief |
Compared with BF422G, BF422ZL1G offers identical electrical behavior with optimized logistics for tape-and-reel–compatible ammo pack feeding; versus MPSA42, it trades 50 V headroom for superior thermal resistance and tighter hFE consistency, making it preferable in compact, temperature-sensitive designs.
Availability
BF422ZL1G is available at Aetrix Electronics and suitable for horizontal deflection circuits, off-line SMPS switching, and industrial control interfaces requiring stable component supply, RoHS compliance, and TO-92 form factor continuity.
Supply support for BF422ZL1G 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, delivering power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The BF422ZL1G belongs to onsemi's high-voltage bipolar transistor product line, engineered specifically for reliability-critical switching in CRT, power conversion, and industrial pulse applications where voltage margin and thermal stability are essential.
FAQ
What is the maximum collector-emitter voltage rating for BF422ZL1G?
The BF422ZL1G has a guaranteed minimum V(BR)CEO of 250 Vdc at IC = 1.0 mAdc and IB = 0. This rating is validated per onsemi's test conditions and defines the absolute maximum DC voltage the device can block in common-emitter configuration without breakdown. Designers should apply derating per application safety standards when using BF422ZL1G in 230 V AC line-derived circuits.
Does BF422ZL1G have Pb-free construction?
Yes, BF422ZL1G is explicitly marked as Pb-free in onsemi's ordering information and package documentation. It complies with RoHS Directive 2011/65/EU and uses lead-free solderability finishes compatible with standard reflow profiles. The "G" suffix in BF422ZL1G confirms this environmental compliance, distinguishing it from non-Pb-free variants like BF422ZL1.
What is the thermal resistance of BF422ZL1G, and how does it affect layout?
BF422ZL1G has a specified RJA of 150 °C/W when mounted on a FR4 board with 200 mm² of 1 oz copper and 5 mm lead length. This value directly informs PCB copper area requirements: reducing copper area increases junction temperature rise under load. For continuous 50 mA operation, designers must verify that calculated TJ remains below 150°C using actual ambient and power dissipation values.
Can BF422ZL1G replace BF420 in existing designs?
BF422ZL1G is not a direct replacement for BF420 due to its lower VCEO (250 V vs. 300 V) and V(BR)CBO ratings. While both share identical package, pinout, and hFE, substituting BF422ZL1G into a BF420 design risks premature breakdown in circuits operating near 300 V. Validation of voltage stress margins is mandatory before any cross-substitution involving BF422ZL1G and BF420.
What is the typical current gain (hFE) of BF422ZL1G at operating conditions?
The BF422ZL1G guarantees hFE ≥ 50 when tested at IC = 25 mAdc and VCE = 20 Vdc. This minimum value is specified across the full temperature range (−55°C to +150°C). Actual measured hFE may exceed 50 depending on bias point and temperature, but circuit designs must be verified using the guaranteed minimum to ensure functionality across all operating conditions.
BF422ZL1G 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):
- 50 mA
- Voltage - Collector Emitter Breakdown (Max):
- 250 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 2mA, 20mA
- Current - Collector Cutoff (Max):
- -
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 50 @ 25mA, 20V
- Power - Max:
- 830 mW
- Frequency - Transition:
- 60MHz
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-92 (TO-226)
BF422ZL1G FAQ
1.How can I place an order for BF422ZL1G through Aetrix?
Please submit a Request for Quotation (RFQ) for BF422ZL1G 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 BF422ZL1G reliable?
The price and inventory of BF422ZL1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BF422ZL1G is usually 5 days.
3.What payment methods are accepted for BF422ZL1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BF422ZL1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BF422ZL1G?
BF422ZL1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BF422ZL1G 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 BF422ZL1G?
For technical support, including BF422ZL1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BF422ZL1G requirements.
6.How does Aetrix verify that BF422ZL1G is sourced from the original manufacturer or authorized distributors?
All BF422ZL1G 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 BF422ZL1G meets industry standards.
7.What is the process for return or replacement of BF422ZL1G?
All BF422ZL1G units undergo pre-shipment inspection (PSI). If there is an issue with BF422ZL1G, 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 BF422ZL1G part is unused and in its original packaging.
Return procedure for BF422ZL1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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