Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Diodes Incorporated BAS21T-7-F

Name: BAS21T-7-F
Brand: Diodes Incorporated
SKU: BAS21T-7-F
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BAS21T-7-F

Manufacturer:: Diodes Incorporated

Category:: Single Diodes

Package:: SOT-523

Datasheet:: BAS21T-7-F.pdf

Description:: DIODE GEN PURP 200V 200MA SOT523

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:4,390

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

BAS21T-7-F from Diodes Incorporated is a surface-mount fast-switching silicon switching diode in SOT-523 package, rated for 250 V repetitive peak reverse voltage, 400 mA forward current, and 50 ns reverse recovery time. It serves as a high-speed signal routing or clamping element in low-power analog and digital interface circuits, including ESD protection front-ends and level-shifting nodes.

For engineers reviewing the BAS21T-7-F datasheet, BAS21T-7-F pinout, BAS21T-7-F application, or BAS21T-7-F equivalent, key selection criteria include its 250 V V_RRM, 50 ns t_rr, 1.25 V V_F @ 200 mA, 5.0 pF C_T @ 0 V, and thermal resistance of 833 °C/W - all critical for high-frequency switching integrity and PCB space-constrained designs.

Technical Context

The BAS21T-7-F is a planar epitaxial silicon PN junction diode optimized for fast transient response and low capacitance. Its 50 ns reverse recovery time and 5.0 pF junction capacitance at zero bias enable reliable operation in 1–10 MHz signal path switching, clamping, and polarity detection.

Designed for ambient temperatures from –65 °C to +150 °C and rated for 150 mW power dissipation on FR-4 with recommended pad layout, it supports stable performance in thermally demanding consumer and industrial control modules where lead-free compliance and small footprint are mandatory.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	250 V - supports DC blocking in 200 V rail systems with 25 % safety margin
t_rr	50 ns - enables clean edge transitions in 10 MHz digital signal routing
C_T	5.0 pF @ 0 V - minimizes signal loading in RF detector and sample-hold inputs
V_F	1.25 V @ 200 mA - limits conduction loss to ≤250 mW in pulsed 200 mA paths
R_θJA	833 °C/W - requires minimal copper area for thermal management in SOT-523 layout
I_FSM	2.5 A @ 1 µs - withstands brief ESD-induced current surges without degradation

Pinout & Package

Package: SOT-523 - ultra-compact 3-terminal plastic surface-mount case (1.60 × 1.60 × 0.75 mm), lead-free matte tin-plated, moisture sensitivity level 1, UL 94V-0 rated.

Pin/Terminal	Circuit Role	Design Meaning
Anode (Pin 1)	Forward current entry node	Connected to higher-potential side in clamping or rectification paths; marked by device top-side "T3" symbol adjacent to this pin
Cathode (Pin 2)	Forward current exit node	Internally bonded to die cathode; tied to reference or lower-potential rail; electrically isolated from package tab (no thermal pad)
No-connect (Pin 3)	Non-functional terminal	Internal die bond wire stub; must remain unconnected per datasheet - floating or grounded connection degrades t_rr and leakage

Key Features

Feature	Design Value
Ultra-fast recovery	50 ns t_rr ensures minimal switching distortion in 10 MHz clock distribution networks
High-voltage blocking	250 V V_RRM allows direct use across 24–48 V industrial I/O lines without series resistors
Low junction capacitance	5.0 pF C_T preserves signal rise/fall times in high-impedance sensor interface nodes
Green RoHS-compliant construction	Halogen- and antimony-free molding compound (<900 ppm Br/Cl, <1000 ppm Sb) meets IPC-1752A Tier 1 reporting

Applications

USB 2.0 Data Line Protection

Automotive CAN Bus Transceiver Clamp

Use Scenario: Bidirectional ESD suppression on D+/D− lines of USB 2.0 peripherals operating up to 480 Mbps.

IC Role / Device Role: Fast-clamping diode in low-capacitance TVS-assisted architecture.

Use Value: 5.0 pF C_T prevents signal integrity loss; 50 ns t_rr avoids latch-up during ±8 kV contact discharge events.

Use Scenario: Overvoltage clamp on CAN_H/CAN_L differential pair in 12 V automotive body control modules.

IC Role / Device Role: Standoff diode limiting transients to ±250 V while preserving common-mode range.

Use Value: 250 V V_RRM accommodates load-dump spikes; SOT-523 footprint enables placement within 3 mm of connector.

Industrial PLC Digital Input Conditioning

Portable Medical Sensor Signal Routing

Use Scenario: Polarity-insensitive front-end protection for 24 V DC digital input channels accepting NPN/PNP sourcing/sinking signals.

IC Role / Device Role: Reverse-polarity safeguard and transient suppressor before optocoupler input.

Use Value: 400 mA I_FM handles sustained 24 V short-circuit currents; 833 °C/W R_θJA permits operation at 75 °C ambient without derating.

Use Scenario: Multiplexer-based signal path selection in battery-powered ECG front-ends requiring sub-10 pF channel capacitance.

IC Role / Device Role: Low-leakage analog switch enabling bidirectional AC-coupled signal routing.

Use Value: 15 nA I_R @ 100 °C preserves DC accuracy; 5.0 pF C_T maintains >100 kHz bandwidth across switched paths.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BAS16-7-F	V_RRM = 100 V, t_rr = 4 ns, C_T = 2.0 pF - faster but lower voltage rating	Suitable only for ≤36 V logic-level interfaces; insufficient for 48 V industrial I/O	Select when speed dominates over voltage margin and board space allows larger SOT-23 footprint
1N4148W-7-F	V_RRM = 100 V, t_rr = 4 ns, C_T = 4.0 pF - slightly lower capacitance, same voltage limit	Not rated for >100 V reverse stress; unsuitable for 200 V DC-blocking roles	Prefer for general-purpose 5 V/3.3 V signal steering where cost and availability outweigh voltage headroom needs

Compared with BAS16-7-F and 1N4148W-7-F, the BAS21T-7-F uniquely delivers 250 V blocking capability in SOT-523 without sacrificing 50 ns switching speed - making it the only option among the three for compact, high-voltage signal conditioning in space-constrained 24–48 V embedded systems.

Availability

BAS21T-7-F is available at Aetrix Electronics and suitable for USB 2.0 interface protection, automotive CAN bus clamping, and industrial PLC digital input conditioning requiring stable component supply across multi-year production cycles.

Supply support for BAS21T-7-F 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The BAS21T belongs to Diodes' high-speed switching diode product line, engineered specifically for compact, high-reliability signal routing and transient suppression in industrial, automotive, and portable electronics.

FAQ

What is the maximum continuous forward current rating for BAS21T-7-F?

The BAS21T-7-F is rated for 400 mA continuous forward current (I_FM) at 25 °C ambient, provided terminals are maintained at ambient temperature using the recommended FR-4 pad layout. Derating begins above 25 °C per the 150 mW power dissipation limit and 833 °C/W thermal resistance.

Does BAS21T-7-F have a thermal pad or exposed cathode connection?

No. The SOT-523 package has no thermal pad or exposed metal slug. Pin 2 (cathode) is the sole functional terminal; Pin 3 is a non-connected internal stub and must remain unconnected. Thermal performance relies entirely on PCB copper area under the standard footprint.

Can BAS21T-7-F be used in place of a 1N4148 in 5 V logic circuits?

Yes, electrically - its 1.25 V V_F @ 200 mA and 50 ns t_rr meet or exceed 1N4148 specs. However, its 250 V V_RRM and SOT-523 footprint require layout verification; it is not a drop-in replacement due to different pinout and smaller size.

Is BAS21T-7-F compliant with JEDEC moisture sensitivity level requirements?

Yes. The device is rated MSL Level 1 per J-STD-020D, meaning it may be stored indefinitely at ≤30 °C/85 % RH without baking prior to reflow. This eliminates pre-bake steps in standard SMT assembly for most production environments.

BAS21T-7-F Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: SOT-523

Packaging:: Tape & Reel (TR)

Product Status:: Active

Technology:: Standard

Voltage - DC Reverse (Vr) (Max):: 200 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:: SOT-523

Operating Temperature - Junction:: -65°C ~ 150°C

BAS21T-7-F FAQ

1.How can I place an order for BAS21T-7-F through Aetrix?

Please submit a Request for Quotation (RFQ) for BAS21T-7-F 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 BAS21T-7-F reliable?

The price and inventory of BAS21T-7-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BAS21T-7-F is usually 5 days.

3.What payment methods are accepted for BAS21T-7-F?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BAS21T-7-F transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BAS21T-7-F?

BAS21T-7-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BAS21T-7-F 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 BAS21T-7-F?

For technical support, including BAS21T-7-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BAS21T-7-F requirements.

6.How does Aetrix verify that BAS21T-7-F is sourced from the original manufacturer or authorized distributors?

All BAS21T-7-F 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 BAS21T-7-F meets industry standards.

7.What is the process for return or replacement of BAS21T-7-F?

All BAS21T-7-F units undergo pre-shipment inspection (PSI). If there is an issue with BAS21T-7-F, 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 BAS21T-7-F part is unused and in its original packaging.

Return procedure for BAS21T-7-F:

1.Submit a request within 90 days.

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

Tech Hub

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

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…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

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…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

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…

2026-08-11 LDO Regulator: Dropout Voltage, Noise, PSRR and Power Dissipation

LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…

2026-08-06 Conditional Access Module: CAM, CI/CI+ and DVB Security

Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…

2026-08-03 Electronic Component Obsolescence: EOL Risks, Replacement Options and Last-Time Buy Strategy

Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.

2026-07-29 18650 Battery: Voltage, Capacity, Charging and Pack Design

18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…

2026-07-27 Hall Effect Sensor: Working Principle, Types, Circuits and Applications

Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…

2026-07-20 Product Change Notification (PCN) in Electronic Components: Meaning and Supply Chain Response

Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…

2026-07-19 Blend Door Actuator: Symptoms, Location, Reset and Replacement Guide

A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…