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Home > Products > Discrete Semiconductor Products > Diodes > Rectifiers > Single Diodes

Nexperia USA Inc. BAS21/8R

Name: BAS21/8R
Brand: Nexperia USA Inc.
SKU: BAS21/8R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BAS21/8R

Manufacturer:: Nexperia USA Inc.

Category:: Single Diodes

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: BAS21/8R.pdf

Description:: DIODE GP 250V 200MA TO236AB

Quantity:: RFQ Add To RFQ list

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Inventory:395,630

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Product details

Overview

BAS21/8R from ON Semiconductor is a high-speed switching diode in SOT-23 package, rated for 250 V peak repetitive reverse voltage (V_RRM), 225 mA average forward current (I_F(AV)), and 50 ns reverse recovery time (t_rr). It serves as a signal-level clamp or fast rectifier in low-power logic interface and analog sampling circuits.

For engineers reviewing the BAS21/8R datasheet, BAS21/8R pinout, BAS21/8R application, or BAS21/8R equivalent, key selection criteria include reverse recovery speed, junction capacitance at 0 V (C_j = 2.5 pF), leakage current at 200 V (I_R = 100 nA), and thermal resistance (R_θJA = 357 °C/W).

Technical Context

The BAS21/8R is a planar epitaxial silicon switching diode optimized for high-speed operation in digital and analog signal paths. Its low stored charge (Q_rr = 4 nC) and fast t_rr enable clean edge transitions in 10–50 MHz pulse applications.

It operates with a forward voltage drop of 1.25 V at 200 mA and exhibits stable performance across -65 °C to +150 °C junction temperature range. The device is not designed for power rectification but for precision timing, clamping, and signal steering where minimal delay and low capacitive loading are critical.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	250 V - supports signal clamping in industrial I/O lines up to 24 V nominal with safety margin
I_F(AV)	225 mA - sufficient for logic-level signal routing and low-current bias networks
t_rr	50 ns - enables reliable operation in 10–20 MHz digital switching and sample-hold circuits
C_j @ 0 V	2.5 pF - minimizes capacitive loading on high-impedance nodes such as op-amp inputs or RF detectors
I_R @ 200 V	100 nA - ensures low leakage in precision voltage reference and sensor conditioning paths
R_θJA	357 °C/W - requires careful PCB copper area planning for sustained 150 mW dissipation at ambient

Pinout & Package

Package: SOT-23 (TO-236AB), surface-mount, 3-terminal plastic package with standard pin assignment.

Pin/Terminal	Circuit Role	Design Meaning
1 (Anode)	Forward current entry	Connected to signal source or positive rail in clamping/steering configuration
2 (Cathode)	Forward current exit / reverse blocking terminal	Connected to load or reference node; defines polarity of conduction and breakdown
3 (Anode)	Internal die connection - redundant anode bond	Not electrically isolated; tied internally to Pin 1 for mechanical robustness and thermal path

Key Features

Feature	Design Value
High V_RRM / small footprint	250 V standoff in SOT-23 enables compact protection in space-constrained PLC I/O modules
Low Q_rr	4 nC stored charge reduces switching-induced transients in analog multiplexer front-ends
Specified t_rr at 100 mA	50 ns measured under standardized 100 mA IF/IR conditions - directly comparable across vendors
Wide T_J range	-65 °C to +150 °C operation supports deployment in automotive engine control and industrial motor drives

Applications

Logic-Level Clamping

Analog Signal Steering

Use Scenario: Protecting CMOS input pins from overvoltage transients in microcontroller-based sensor interfaces.

IC Role / Device Role / Timing Role: Fast-acting clamp diode limiting input swing to V_CC + 0.7 V and GND − 0.5 V.

Use Value: Prevents latch-up without adding RC delay; t_rr < 50 ns avoids distortion in 10 MHz SPI clock lines.

Use Scenario: Routing analog signals between multiple ADC channels using discrete diode steering.

IC Role / Device Role / Timing Role: Low-capacitance bidirectional switch enabling channel selection via bias control.

Use Value: C_j = 2.5 pF minimizes crosstalk and settling error in 12-bit, 1 MSPS data acquisition systems.

Pulse Width Modulation Demodulation

High-Voltage Logic Interface

Use Scenario: Recovering baseband signals from PWM carriers in motor feedback circuits.

IC Role / Device Role / Timing Role: Edge-detecting rectifier converting PWM edges into clean logic pulses.

Use Value: 50 ns t_rr preserves rise/fall fidelity for 20 kHz carrier demodulation with <1% duty cycle error.

Use Scenario: Level-shifting 24 V industrial fieldbus signals to 3.3 V MCU GPIOs.

IC Role / Device Role / Timing Role: High-V_RRM signal translator providing galvanic isolation via series impedance.

Use Value: 250 V rating accommodates surge transients per IEC 61000-4-5 while maintaining sub-ns propagation delay.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed switching diode applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BAS16,115 (Nexperia)	V_RRM = 80 V, t_rr = 4 ns, C_j = 1.5 pF	Lower voltage rating limits use to 5–12 V logic domains; faster t_rr suits >50 MHz RF switching	Select when operating below 80 V and requiring minimal delay; avoid for 24 V fieldbus clamping.
1N4148WS (ON Semiconductor)	V_RRM = 100 V, t_rr = 4 ns, I_F(AV) = 150 mA	Lower current and voltage ratings reduce margin in industrial I/O; identical SOT-323 package	Use only in cost-sensitive consumer designs with ≤12 V rails and <100 mA peak current.

Compared with BAS16,115 and 1N4148WS, the BAS21/8R uniquely balances 250 V standoff, 225 mA current capability, and 50 ns recovery-making it the only option among the three qualified for 24 V PLC input protection with sustained thermal reliability.

Availability

BAS21/8R is available at Aetrix Electronics and suitable for industrial I/O modules, sensor interface boards, and motor control feedback circuits requiring stable component supply and long-term manufacturability.

Supply support for BAS21/8R 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

ON Semiconductor is a global semiconductor manufacturer focused on energy-efficient electronics, delivering power management, analog, sensing, and connectivity solutions.

The BAS21 series belongs to ON Semiconductor's high-speed switching diode product line, engineered specifically for signal integrity preservation in industrial automation, automotive body electronics, and precision instrumentation.

FAQ

What is the maximum continuous reverse voltage the BAS21/8R can withstand?

The BAS21/8R has a peak repetitive reverse voltage (V_RRM) rating of 250 V. This is the maximum instantaneous reverse voltage the device can block continuously without breakdown. Operation above this value risks avalanche conduction or permanent damage, even for short durations. Derating by 20% is recommended for reliability in industrial environments with voltage transients.

Is the BAS21/8R suitable for use in 5 V logic clamping circuits?

Yes - the BAS21/8R is fully compatible with 5 V logic clamping. Its low forward voltage (~0.85 V at 10 mA) and 250 V V_RRM provide ample margin. However, its 2.5 pF junction capacitance is higher than dedicated logic-clamp diodes like the BAV99; for ultra-high-speed 5 V interfaces (>100 MHz), lower-C_j alternatives may be preferred.

How does the SOT-23 package of the BAS21/8R affect thermal performance?

The SOT-23 package delivers R_θJA = 357 °C/W under standard JEDEC test conditions (1-inch² copper pad). At 225 mA forward current and 1.25 V drop, power dissipation reaches ~280 mW, raising junction temperature by ~100 °C above ambient. Adequate PCB copper area and airflow are required to maintain T_J ≤ 150 °C in continuous operation.

Can the BAS21/8R replace the 1N4148 in existing designs?

It can replace the 1N4148 in applications requiring higher V_RRM or I_F(AV), but not as a direct drop-in due to differences in t_rr (50 ns vs. 4 ns) and C_j (2.5 pF vs. 4 pF). In high-frequency signal paths, the slower recovery may cause timing skew. Verify waveform integrity and thermal margin before substitution.

BAS21/8R Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Bulk

Product Status:: Active

Technology:: Standard

Voltage - DC Reverse (Vr) (Max):: 250 V

Current - Average Rectified (Io):: 200mA

Voltage - Forward (Vf) (Max) @ If:: 1.25 V @ 200 mA

Speed:: Small Signal =< 200mA (Io), Any Speed

Reverse Recovery Time (trr):: 50 ns

Current - Reverse Leakage @ Vr:: 100 nA @ 200 V

Capacitance @ Vr, F:: 5pF @ 0V, 1MHz

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: TO-236AB

Operating Temperature - Junction:: 150°C (Max)

BAS21/8R FAQ

1.How can I place an order for BAS21/8R through Aetrix?

Please submit a Request for Quotation (RFQ) for BAS21/8R 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 BAS21/8R reliable?

The price and inventory of BAS21/8R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BAS21/8R is usually 5 days.

3.What payment methods are accepted for BAS21/8R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BAS21/8R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BAS21/8R?

BAS21/8R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BAS21/8R 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 BAS21/8R?

For technical support, including BAS21/8R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BAS21/8R requirements.

6.How does Aetrix verify that BAS21/8R is sourced from the original manufacturer or authorized distributors?

All BAS21/8R 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 BAS21/8R meets industry standards.

7.What is the process for return or replacement of BAS21/8R?

All BAS21/8R units undergo pre-shipment inspection (PSI). If there is an issue with BAS21/8R, 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 BAS21/8R part is unused and in its original packaging.

Return procedure for BAS21/8R:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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