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onsemi BF423ZL1G
- Part No.:
- BF423ZL1G
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Datasheet:
-
BF423ZL1G.pdf
- Description:
- TRANS PNP 250V 0.5A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:5,912
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Product details
Overview
BF423ZL1G from onsemi is a PNP silicon high-voltage transistor rated for −250 VCEO, −250 VCBO, and −5.0 VEBO, with continuous collector current of −500 mA and DC current gain (hFE) ≥50 at IC = −25 mA, VCE = −20 V - used in flyback converter snubber networks, relay drivers, and HV switching stages in industrial power supplies.
For engineers reviewing the BF423ZL1G datasheet, pinout, applications, or equivalent options, key selection criteria include verified −250 V breakdown rating, TO-92 package thermal resistance (RJA = 150 °C/W), VCE(sat) ≤ −0.5 V at IC/IB = 10, fT = 60 MHz, and Cre = 2.8 pF for high-frequency switching stability.
Technical Context
The BF423ZL1G operates as a medium-speed, high-voltage PNP switch with fixed gain structure optimized for linear and saturated-mode operation in off-line power circuits. Its −250 V ratings enable direct use across 230 VAC mains-referenced nodes without cascading.
Thermal design relies on its TO-92 package's RJL = 68 °C/W (junction-to-lead) and specified mounting on FR4 with 200 mm² copper, supporting sustained 830 mW dissipation at TA = 25°C before derating at 6.6 mW/°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | −250 Vdc - supports direct switching in 230 VAC-derived rails with ≥2× safety margin |
| hFE | ≥50 at −25 mA / −20 V - ensures reliable base drive sizing for <10 mA control signals |
| VCE(sat) | ≤ −0.5 V at −20 mA / −2 mA - limits conduction loss to <10 mW in saturated switching |
| fT | 60 MHz - enables stable operation up to ~5–10 MHz switching in snubber or oscillator roles |
| Cre | 2.8 pF at −30 V - minimizes Miller feedback in high-dV/dt environments like flyback primary clamping |
| RJA | 150 °C/W - requires ≥200 mm² copper pour for full 830 mW rating at ambient 25°C |
Pinout & Package
BF423ZL1G uses the standard TO-92 (Case 29, Style 14) package with straight leads in ammo pack configuration. Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base - confirmed per onsemi marking diagram and package outline drawing.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Emitter) | Current sink reference terminal | Connected to system ground or negative rail; carries full load current in common-base configurations |
| 2 (Collector) | High-voltage output node | Rated for −250 V standoff; ties to transformer primary, relay coil, or HV bus in switching applications |
| 3 (Base) | Control input | Receives negative-turn-on current; requires series resistor to limit IB ≤ −2 mA for saturation |
Key Features
| Feature | Design Value |
|---|---|
| Pb-free, Halogen Free/BFR Free | Complies with RoHS Directive 2011/65/EU and JEDEC JS709B; no lead or brominated flame retardants |
| High VCEO / VCBO | −250 V rating enables single-transistor replacement of older −200 V parts in legacy 230 VAC designs |
| Low VCE(sat) | ≤ −0.5 V reduces power loss by >30% vs. comparable −250 V transistors with VCE(sat) > −0.7 V |
| Stable hFE over temperature | hFE remains ≥50 from −55°C to +125°C - simplifies bias network design across industrial temp range |
Applications
| Switched-Mode Power Supply Snubbers | Industrial Relay Drivers |
|---|---|
|
Use Scenario: Clamping voltage spikes across flyback transformer primary during MOSFET turn-off. IC Role / Device Role / Timing Role: High-voltage PNP switch absorbing transient energy into RC network. Use Value: −250 V VCEO withstands reflected 200–220 V spikes without avalanche stress; 2.8 pF Cre minimizes false triggering. |
Use Scenario: Driving 24–48 VDC industrial relays with microcontroller GPIO-level base control. IC Role / Device Role / Timing Role: Saturated PNP interface amplifier sinking relay coil current. Use Value: −500 mA IC rating covers typical 30–100 mA relay coils; VCE(sat) ≤ −0.5 V ensures <50 mW dissipation at full load. |
| AC Line Voltage Sensing Circuits | High-Voltage Signal Level Shifting |
|
Use Scenario: Resistive divider-fed detection of 230 VAC zero-crossing or overvoltage events. IC Role / Device Role / Timing Role: High-impedance PNP switch isolating AC sensing node from low-voltage logic. Use Value: −250 V VCBO allows direct connection to phase line with minimal external protection; IEBO ≤ −100 nA prevents leakage-induced false triggers. |
Use Scenario: Translating −100 V to −200 V logic transitions to 0–3.3 V MCU inputs in test equipment. IC Role / Device Role / Timing Role: Emitter-follower level shifter with grounded emitter and collector referenced to HV rail. Use Value: 60 MHz fT supports clean edge transmission up to 5 MHz; hFE ≥50 ensures predictable gain across temperature. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage PNP transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BF423G | Same die, identical electrical specs; differs only in packaging - bulk box (5000 units) vs. ammo pack (2000 units) | No functional difference; choice depends solely on procurement volume and handling requirements | Select BF423ZL1G for automated SMT feeders requiring ammo-pack tape compatibility; BF423G suits manual assembly or high-volume bulk use. |
| MPSA92 | −300 V VCEO, −300 V VCBO, but lower hFE (min 25), higher VCE(sat) (−1.0 V), and Cre = 4.0 pF | Acceptable where higher voltage margin is critical but switching speed or gain stability is secondary | Choose MPSA92 only if −300 V rating is mandatory and circuit tolerates reduced gain and higher saturation loss. |
Compared with BF423ZL1G, BF423G offers identical performance in bulk packaging, while MPSA92 trades gain and speed for extra 50 V headroom - making BF423ZL1G optimal for cost-sensitive, thermally constrained 230 VAC designs needing consistent hFE and low VCE(sat).
Availability
BF423ZL1G is available at Aetrix Electronics and suitable for switched-mode power supply snubbers, industrial relay drivers, and AC line voltage sensing circuits requiring stable component supply with RoHS-compliant, Pb-free construction.
Supply support for BF423ZL1G 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 IoT applications.
The BF423ZL1G belongs to onsemi's high-voltage bipolar transistor family designed specifically for robust, cost-effective switching in off-line power conversion, motor control interfaces, and industrial signal conditioning circuits.
FAQ
What is the maximum continuous collector current rating for BF423ZL1G?
The BF423ZL1G is rated for −500 mA continuous collector current (IC) at TA = 25°C with proper PCB thermal management. This rating assumes mounting on FR4 with 200 mm² of 1 oz copper and 5 mm lead length. Derating begins at 6.6 mW/°C above 25°C ambient, and actual usable current depends on layout, airflow, and junction temperature limits. The BF423ZL1G must not exceed its 150 °C maximum junction temperature under operating conditions.
Is BF423ZL1G pin-compatible with BF421ZL1G?
No, BF423ZL1G is not pin-compatible with BF421ZL1G in functional replacement terms - although both share the same TO-92 package and pinout (Emitter=1, Collector=2, Base=3), their electrical ratings differ significantly: BF421ZL1G has −300 V VCEO/VCBO, while BF423ZL1G is rated at −250 V. Substituting BF423ZL1G for BF421ZL1G may compromise voltage safety margins in 230 VAC-derived circuits. The BF423ZL1G is intended for applications where −250 V suffices and tighter gain or saturation specs are prioritized.
Does BF423ZL1G support operation at elevated temperatures?
Yes, the BF423ZL1G is qualified for operation from −55°C to +150°C junction temperature. Its DC current gain (hFE) remains ≥50 across this full range when tested at IC = −25 mA and VCE = −20 V, and VCE(sat) stays ≤ −0.5 V at IC = −20 mA and IB = −2 mA. Thermal resistance values (RJA = 150 °C/W, RJL = 68 °C/W) are specified with defined board conditions, and the BF423ZL1G maintains safe operation in industrial environments when heatsinking and layout comply with onsemi's recommended footprint.
What is the typical transition frequency (fT) of BF423ZL1G and how is it measured?
The BF423ZL1G has a typical transition frequency (fT) of 60 MHz, measured under standardized small-signal conditions: IC = −10 mA, VCE = −10 Vdc, and f = 20 MHz. This parameter reflects the frequency at which the transistor's short-circuit current gain drops to unity and indicates usable bandwidth for linear amplification or fast switching. The BF423ZL1G's fT supports stable operation in snubber oscillators and moderate-speed HV signal paths, though practical switching edges are limited by external circuit parasitics and drive strength.
Can BF423ZL1G be used in avalanche mode?
No, the BF423ZL1G is not rated or characterized for controlled avalanche operation. Its absolute maximum ratings define VCEO = −250 V and VCBO = −250 V as non-repetitive breakdown limits - exceeding these voltages risks irreversible device failure. The BF423ZL1G is designed for forward-active and saturation-mode operation only. For avalanche-tolerant designs, dedicated avalanche-rated transistors such as the MJD122 or ZTX653 should be selected instead of relying on BF423ZL1G beyond its specified voltage limits.
BF423ZL1G 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:
- PNP
- Current - Collector (Ic) (Max):
- 500 mA
- Voltage - Collector Emitter Breakdown (Max):
- 250 V
- Vce Saturation (Max) @ Ib, Ic:
- 500mV @ 2mA, 20mA
- Current - Collector Cutoff (Max):
- 10nA (ICBO)
- 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)
BF423ZL1G FAQ
1.How can I place an order for BF423ZL1G through Aetrix?
Please submit a Request for Quotation (RFQ) for BF423ZL1G 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 BF423ZL1G reliable?
The price and inventory of BF423ZL1G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BF423ZL1G is usually 5 days.
3.What payment methods are accepted for BF423ZL1G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BF423ZL1G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BF423ZL1G?
BF423ZL1G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BF423ZL1G 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 BF423ZL1G?
For technical support, including BF423ZL1G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BF423ZL1G requirements.
6.How does Aetrix verify that BF423ZL1G is sourced from the original manufacturer or authorized distributors?
All BF423ZL1G 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 BF423ZL1G meets industry standards.
7.What is the process for return or replacement of BF423ZL1G?
All BF423ZL1G units undergo pre-shipment inspection (PSI). If there is an issue with BF423ZL1G, 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 BF423ZL1G part is unused and in its original packaging.
Return procedure for BF423ZL1G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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