My Inquiry
My Account
onsemi BF422ZL1
- Part No.:
- BF422ZL1
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-226-3, TO-92-3 Long Body, Formed Leads
- Datasheet:
-
BF422ZL1.pdf
- Description:
- TRANS NPN 250V 0.05A TO92
- Quantity:
- Payment:
- Shipping:
Inventory:6,074
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BF422ZL1 from onsemi is an NPN silicon high-voltage transistor designed for switching and amplification in line-powered and industrial control circuits. It features VCEO = 250 V, IC = 50 mA continuous, hFE ≥ 50 at 25 mA/20 V, fT = 60 MHz, and TO-92 package with emitter-collector-base pinout. It is used in horizontal deflection output stages and flyback converter drivers.
For engineers reviewing the BF422ZL1 datasheet, pinout, applications, or equivalent options, key selection criteria include high-voltage breakdown (VCEO, VCBO), DC current gain stability across temperature, saturation voltage under defined drive conditions, thermal resistance (RJA = 150 °C/W), and Pb-free compliance per ordering suffix "ZL1".
Technical Context
The BF422ZL1 operates as a general-purpose NPN bipolar junction transistor optimized for high-voltage switching where collector-emitter blocking capability up to 250 Vdc and low saturation voltage (VCE(sat) ≤ 0.5 V at IC/IB = 10) are critical. Its fT of 60 MHz supports moderate-frequency switching in CRT deflection and SMPS auxiliary circuits.
It uses standard TO-92 packaging with defined lead assignments (Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base) and exhibits specified cutoff leakage (ICBO ≤ 10 nA at 200 V, IEBO ≤ 100 nA at 5 V), enabling reliable operation in high-impedance bias networks and high-side switch configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 250 Vdc - Supports operation in 230 VAC-derived supply rails with margin for transient spikes. |
| IC (continuous) | 50 mAdc - Sufficient for driving small relays, gate resistors, or low-power flyback transformer bases. |
| hFE | ≥50 at IC = 25 mA, VCE = 20 V - Ensures predictable base drive requirements in linear and saturated switching modes. |
| VCE(sat) | ≤0.5 V at IC = 20 mA, IB = 2 mA - Minimizes conduction loss and self-heating in pulsed switching applications. |
| fT | 60 MHz - Enables stable gain in RF preamp stages up to ~10 MHz and fast turn-off in <100 ns pulse circuits. |
| RJA | 150 °C/W - Requires minimal copper area (200 mm² 1 oz Cu) for thermal management at full power dissipation. |
| Cre | ≤1.6 pF at VCB = 30 V - Limits Miller feedback in high-gain amplifier configurations and improves switching speed. |
Pinout & Package
BF422ZL1 is housed in a TO-92 (Case 29, Style 14) plastic package with 3 leads, lead-free finish, and standard through-hole mounting. Package dimensions conform to ON Semiconductor's CASE 029−11 specification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | Emitter | Reference node for base-emitter bias; connects to ground or low-side return path in common-emitter switches. |
| Pin 2 | Collector | High-voltage output node; handles up to 250 Vdc blocking and 50 mA continuous current. |
| Pin 3 | Base | Current-controlled input; requires ~2 mA drive for full saturation at 20 mA collector load. |
Key Features
| Feature | Design Value |
|---|---|
| High VCEO rating | 250 Vdc enables use in 230 VAC line-referenced circuits without external snubbers or voltage clamping. |
| Pb-free construction | ZL1 suffix confirms RoHS-compliant lead finish and compatibility with lead-free reflow profiles. |
| Low VCE(sat) | ≤0.5 V reduces power loss and thermal stress during sustained conduction in relay drivers and lamp ballasts. |
| Stable hFE over temperature | Specified minimum gain maintained from −55°C to +125°C, supporting industrial ambient operation. |
| Controlled Cre | ≤1.6 pF minimizes unwanted coupling in high-frequency amplifier feedback paths and improves switching edge fidelity. |
Applications
| Horizontal Deflection Output | Flyback Converter Driver |
|---|---|
Use Scenario: Horizontal scan circuit in CRT-based monitors and TVs requiring precise timing and high-voltage pulse generation. IC Role / Device Role / Timing Role: Switching transistor in damper diode–coupled output stage, handling repetitive 15.734 kHz pulses with 250 V peak collector swing. Use Value: High VCEO and low VCE(sat) reduce flyback energy loss and improve waveform fidelity at line frequency. | Use Scenario: Primary-side switch driver in low-power offline flyback converters for AC/DC adapters and auxiliary supplies. IC Role / Device Role / Timing Role: Low-side BJT switch controlling base current of main power transistor or directly driving transformer primary via resistor-coupled interface. Use Value: 60 MHz fT and controlled Cre support clean turn-on/turn-off edges, minimizing EMI in <5 W designs. |
| Relay and Solenoid Driver | High-Voltage Signal Amplifier |
Use Scenario: Interface between microcontroller GPIO and 24–48 VDC industrial relays or pneumatic solenoids. IC Role / Device Role / Timing Role: Common-emitter switch providing galvanic isolation and current gain to energize coil loads with <5 mA MCU output. Use Value: Guaranteed hFE ≥ 50 ensures reliable saturation with standard logic-level base drive, eliminating need for Darlington configuration. | Use Scenario: Low-noise preamplifier stage for sensor signals referenced to high-voltage rails (e.g., plasma detection, HV monitoring). IC Role / Device Role / Timing Role: Common-emitter amplifier biased with high-impedance network, operating at fixed VCE = 20 V and IC = 10 mA. Use Value: Low ICBO (≤10 nA) prevents leakage-induced offset drift in precision DC-coupled gain blocks. |
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 |
|---|---|---|---|
| BF422RL1 | Same die, TO-92 tape-and-reel packaging (2000 pcs/reel); identical electrical specs and thermal performance. | No functional difference; selected for automated SMT placement instead of manual or ammo-pack insertion. | Choose BF422RL1 for pick-and-place assembly; BF422ZL1 for hand-soldering or low-volume prototyping. |
| 2N5551 | Lower VCEO (160 V), higher IC (600 mA), higher hFE (80–250), but larger RJA (200 °C/W) and no guaranteed 250 V rating. | Suitable only in sub-160 V circuits; not drop-in for 230 VAC-derived designs requiring 250 V margin. | Select 2N5551 only when voltage stress is below 150 V and higher current drive is needed; verify thermal derating. |
Compared with BF422RL1, BF422ZL1 offers identical performance in a manually handled ammo pack format; compared with 2N5551, BF422ZL1 provides assured 250 V blocking but lower current capacity-making it optimal for voltage-critical, medium-speed switching where reliability at line voltage is mandatory.
Availability
BF422ZL1 is available at Aetrix Electronics and suitable for horizontal deflection circuits, flyback converter drivers, relay interface modules, and high-voltage signal amplifiers requiring stable component supply and Pb-free compliance.
Supply support for BF422ZL1 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 innovation for automotive, industrial, cloud, and intelligent edge applications.
The BF422ZL1 belongs to onsemi's high-voltage bipolar transistor product line, engineered specifically for robust switching and amplification in line-powered consumer and industrial equipment where voltage endurance and thermal stability are essential.
FAQ
What is the maximum collector-emitter voltage rating for BF422ZL1?
The BF422ZL1 has a guaranteed minimum VCEO rating of 250 Vdc under test condition IC = 1.0 mAdc and IB = 0. This rating allows safe operation in 230 VAC mains-derived circuits with sufficient safety margin against transients. The device must not be operated beyond this limit without external clamping or derating per thermal constraints.
Is BF422ZL1 RoHS-compliant and lead-free?
Yes, BF422ZL1 is RoHS-compliant and manufactured with a lead-free finish, as confirmed by the "ZL1" suffix in the part number and onsemi's official Pb-Free Packaging documentation. It meets JEDEC J-STD-020 moisture sensitivity level (MSL) requirements for standard reflow processes and is qualified for lead-free soldering.
What is the pin configuration of BF422ZL1 in the TO-92 package?
The BF422ZL1 uses standard TO-92 pinout: Pin 1 is Emitter, Pin 2 is Collector, and Pin 3 is Base - verified in onsemi's BF420/D datasheet, Figure 1 (Marking Diagram) and Package Dimensions section. This configuration is consistent across all BF42x variants and must be observed to avoid reverse-bias damage or incorrect switching behavior.
How does BF422ZL1 differ from BF420ZL1?
The BF422ZL1 differs from BF420ZL1 primarily in its VCEO and VCBO ratings: BF422ZL1 is rated at 250 V, while BF420ZL1 is rated at 300 V. All other parameters-including hFE, VCE(sat), fT, and package-are identical. BF422ZL1 is selected when 250 V suffices and cost or inventory optimization is prioritized.
What thermal derating applies to BF422ZL1 above 25°C ambient?
BF422ZL1 has a thermal derating factor of 6.6 mW/°C above 25°C ambient, based on its 830 mW maximum dissipation at TA = 25°C. When mounted on a FR4 board with 200 mm² of 1 oz copper and 5 mm lead length, power must be reduced linearly beyond 25°C to maintain junction temperature ≤150°C. At 75°C ambient, max allowable PD drops to 500 mW.
BF422ZL1 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)
BF422ZL1 FAQ
1.How can I place an order for BF422ZL1 through Aetrix?
Please submit a Request for Quotation (RFQ) for BF422ZL1 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 BF422ZL1 reliable?
The price and inventory of BF422ZL1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BF422ZL1 is usually 5 days.
3.What payment methods are accepted for BF422ZL1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BF422ZL1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BF422ZL1?
BF422ZL1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BF422ZL1 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 BF422ZL1?
For technical support, including BF422ZL1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BF422ZL1 requirements.
6.How does Aetrix verify that BF422ZL1 is sourced from the original manufacturer or authorized distributors?
All BF422ZL1 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 BF422ZL1 meets industry standards.
7.What is the process for return or replacement of BF422ZL1?
All BF422ZL1 units undergo pre-shipment inspection (PSI). If there is an issue with BF422ZL1, 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 BF422ZL1 part is unused and in its original packaging.
Return procedure for BF422ZL1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BF422ZL1 Tags
-
MMBT3906LT1G
onsemi
-
MMBT3904-7-F
Diodes Incorporated
-
MMBT3904LT1G
onsemi
-
MMBT3906-7-F
Diodes Incorporated
-
MMBT3904-TP
Micro Commercial Co
-
MMBT2222A-7-F
Diodes Incorporated
-
BC846BLT1G
onsemi
-
BC847B,215
Nexperia USA Inc.
-
SMMBT3904LT1G
onsemi
-
MMBT2222A-TP
Micro Commercial Co
-
MMBTA06LT1G
onsemi
-
MMBT2222ALT1G
onsemi
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
