My Inquiry
My Account
Nexperia USA Inc. BAS321Z
- Part No.:
- BAS321Z
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Diodes
- Package:
- SC-76, SOD-323
- Datasheet:
-
BAS321Z.pdf
- Description:
- DIODE GEN PURP 200V 250MA SOD323
- Quantity:
- Payment:
- Shipping:
Inventory:28,415
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
BAS321Z from Nexperia is a general-purpose silicon switching diode fabricated in planar technology and housed in an SOD323 (SC-76) surface-mount package. It delivers 250 mA continuous forward current, 200 V reverse voltage rating, 1.25 V forward voltage at 200 mA, 50 ns reverse recovery time, and 300 mW power dissipation - enabling reliable signal routing and polarity protection in compact consumer and industrial PCBs.
For engineers reviewing the BAS321Z datasheet, BAS321Z pinout, BAS321Z application, or BAS321Z equivalent, key selection criteria include its 50 ns switching speed, 250 V peak repetitive reverse voltage, thermal resistance of 366 K/W (junction-to-ambient), cathode/anode terminal assignment, and compatibility with FR4 PCB layouts using standard SOD323 footprints.
Technical Context
The BAS321Z operates as a unidirectional PN junction device optimized for general-purpose switching in low-power DC circuits. Its planar construction ensures stable junction characteristics across temperature, while the SOD323 package enables high-density placement without compromising thermal performance on single-sided FR4 boards.
It exhibits a typical reverse recovery time of 50 ns under IF = IR = 30 mA conditions, with reverse leakage limited to 100 nA at 200 V and 25 °C. Junction temperature remains within safe limits up to 150 °C, supported by a 130 K/W junction-to-solder-point thermal resistance when mounted per recommended footprint.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Forward Voltage | 1.25 V at 200 mA - defines conduction loss in series power path or clamping circuit |
| Reverse Recovery Time | 50 ns - enables use in ≤10 MHz switching applications without excessive switching loss |
| Repetitive Peak Reverse Voltage | 250 V - supports operation in 24 V–48 V industrial bus systems with transient margin |
| Continuous Forward Current | 250 mA - sustains steady-state load current in signal-level logic interface or LED biasing |
| Thermal Resistance (j-a) | 366 K/W - requires minimal copper area for thermal management on standard FR4 PCB |
| Diode Capacitance | 2 pF at 0 V, 1 MHz - minimizes signal distortion in RF-coupled or high-speed digital lines |
| Junction Temperature Limit | 150 °C - allows operation in sealed enclosures with ambient temperatures up to 85 °C |
Pinout & Package
The BAS321Z is packaged in the SOD323 (SC-76) plastic surface-mount case measuring 1.7 mm × 1.25 mm × 0.95 mm, with 1.3 mm lead pitch and tin-plated terminations compatible with reflow and wave soldering per IPC-J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Cathode (K) | Negative terminal; connects to lower-potential node in forward-biased configuration |
| 2 | Anode (A) | Positive terminal; connects to higher-potential node during conduction |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-small SMD footprint | SOD323 package saves >60% board area vs. SOD123 in space-constrained IoT sensor nodes |
| Controlled reverse recovery | 50 ns trr ensures predictable turn-off behavior in PWM-driven LED drivers and level shifters |
| Low forward voltage drop | 1.25 V at 200 mA reduces power loss in battery-powered portable equipment |
| High surge tolerance | 9 A non-repetitive peak forward current withstands ESD-induced transients on I/O lines |
Applications
| USB Port Polarity Protection | Microcontroller I/O Clamping |
|---|---|
Use Scenario: Preventing reverse connection damage to USB Type-A receptacles in embedded host devices. IC Role / Device Role / Timing Role: Unidirectional blocking element placed in series with VBUS line. Use Value: Withstands 200 V reverse standoff and dissipates <100 mW during fault, eliminating need for larger TVS or MOSFET solutions. |
Use Scenario: Limiting GPIO voltage excursions beyond supply rails during hot-plug or ESD events. IC Role / Device Role / Timing Role: Clamp diode connected between I/O pin and VDD/GND rails. Use Value: 2 pF capacitance avoids signal integrity degradation on 10 MHz SPI/MIDI lines; 100 nA leakage preserves sleep-mode current budget. |
| DC-DC Converter Snubber | Optocoupler Input Protection |
Use Scenario: Suppressing flyback voltage spikes across secondary-side rectifiers in isolated flyback converters. IC Role / Device Role / Timing Role: Fast-recovery snubber diode parallel to output rectifier. Use Value: 50 ns trr synchronizes with 500 kHz switching frequency; 250 mA rating handles peak currents in 5 W adapters. |
Use Scenario: Protecting optocoupler LED anodes from reverse polarity during AC-coupled signal conditioning. IC Role / Device Role / Timing Role: Series-blocking diode in front of opto-LED input. Use Value: 1.25 V VF ensures sufficient forward bias margin at 3.3 V logic levels; SOD323 fit accommodates 0.5 mm pitch opto packages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar general-purpose switching diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor MMBD301LT1G | Lower VR (100 V), faster trr (4 ns), same SOD323 package | Restricted to ≤12 V systems; unsuitable for 24 V industrial bus protection | Select only where ultra-fast switching dominates over voltage margin |
| Diodes Incorporated BAV99W-7-F | Dual-series configuration, 70 V VR, 4 ns trr, SOT-363 package | Requires redesign for dual-diode layout; not drop-in for single-diode placements | Use when dual-channel clamping is needed on same net pair |
Compared with MMBD301LT1G and BAV99W-7-F, the BAS321Z provides superior voltage headroom (250 V RRM) and thermal robustness (150 °C Tj) at the cost of moderate switching speed - making it optimal for 24–48 V industrial control, power supply auxiliary rails, and legacy interface protection where reliability outweighs nanosecond-scale timing.
Availability
BAS321Z is available at Aetrix Electronics and suitable for USB port protection, microcontroller I/O clamping, DC-DC converter snubbing, and optocoupler input protection requiring stable component supply and long-term production continuity.
Supply support for BAS321Z 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
Nexperia is a global semiconductor expert focused on high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified and industrial-grade components.
The BAS321Z belongs to Nexperia's general-purpose diode portfolio designed for cost-sensitive, space-constrained applications in consumer electronics, industrial controls, and communication interfaces - emphasizing manufacturability, thermal stability, and consistent parametric performance.
FAQ
Is the BAS321Z suitable for automotive applications?
No. The BAS321Z is explicitly marked as non-automotive qualified in its revision history. It lacks AEC-Q101 qualification, has no automotive-grade screening, and is not tested to automotive temperature or reliability standards. For automotive use, Nexperia offers the BAS321-Q variant, which undergoes extended temperature cycling and failure analysis per AEC requirements.
What is the maximum allowable ambient temperature for continuous operation at 250 mA?
At 250 mA forward current, the maximum permissible ambient temperature is 85 °C when mounted on a standard FR4 PCB with single-sided copper and tin-plated traces. This derives from the 300 mW power dissipation limit and 366 K/W junction-to-ambient thermal resistance - exceeding this ambient temperature risks junction overheating beyond the 150 °C absolute maximum.
Does the BAS321Z have a specified avalanche energy rating?
No. The datasheet does not specify avalanche energy (EAS) or ruggedness under repetitive avalanche conditions. It is rated only for non-repetitive peak forward current (IFSM = 9 A at tp = 1 µs), and operation beyond absolute maximum ratings - including sustained avalanche - may cause irreversible junction damage.
Can the BAS321Z replace the BAS16 in existing designs?
Only with design validation. While both are SOD323 general-purpose diodes, the BAS321Z has higher reverse voltage (250 V vs. 85 V), higher forward current (250 mA vs. 215 mA), and slower trr (50 ns vs. 4 ns). Substitution may improve voltage margin but degrade high-frequency switching performance in oscillator or RF detector circuits.
BAS321Z Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Nexperia USA Inc.
- Series:
- -
- Package/Case:
- SC-76, SOD-323
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Standard
- Voltage - DC Reverse (Vr) (Max):
- 200 V
- Current - Average Rectified (Io):
- 250mA
- Voltage - Forward (Vf) (Max) @ If:
- 1.25 V @ 200 mA
- Speed:
- Fast Recovery =< 500ns, > 200mA (Io)
- Reverse Recovery Time (trr):
- 50 ns
- Current - Reverse Leakage @ Vr:
- 100 nA @ 200 V
- Capacitance @ Vr, F:
- 2pF @ 0V, 1MHz
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-323
- Operating Temperature - Junction:
- 150°C (Max)
BAS321Z FAQ
1.How can I place an order for BAS321Z through Aetrix?
Please submit a Request for Quotation (RFQ) for BAS321Z 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 BAS321Z reliable?
The price and inventory of BAS321Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BAS321Z is usually 5 days.
3.What payment methods are accepted for BAS321Z?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BAS321Z transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BAS321Z?
BAS321Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BAS321Z 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 BAS321Z?
For technical support, including BAS321Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BAS321Z requirements.
6.How does Aetrix verify that BAS321Z is sourced from the original manufacturer or authorized distributors?
All BAS321Z 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 BAS321Z meets industry standards.
7.What is the process for return or replacement of BAS321Z?
All BAS321Z units undergo pre-shipment inspection (PSI). If there is an issue with BAS321Z, 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 BAS321Z part is unused and in its original packaging.
Return procedure for BAS321Z:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BAS321Z Tags
-
1N4448X-TP
Micro Commercial Co
-
1N4148WX-TP
Micro Commercial Co
-
1N4148TR
onsemi
-
MMSD4148T1G
onsemi
-
MMBD914LT3G
onsemi
-
BAS16HT1G
onsemi
-
1N914BWT
onsemi
-
BAS21LT1G
onsemi
-
LL4148
onsemi
-
BAS16LT1G
onsemi
-
MMSD914T1G
onsemi
-
BAV21W-7-F
Diodes Incorporated
Tech Hub
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
