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

Nexperia USA Inc. BAS21-QR

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

Compare

Part No.:: BAS21-QR

Manufacturer:: Nexperia USA Inc.

Category:: Single Diodes

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

Datasheet:: BAS21-QR.pdf

Description:: DIODE SCHOTT 200V 200MA TO236AB

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:19,797

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

Product details

Overview

BAS21-QR from Nexperia is a high-voltage switching diode in SOT23 package, rated for 250 V repetitive peak reverse voltage (V_RRM), with ≤50 ns reverse recovery time (t_rr), 1.25 V forward voltage at 200 mA, and qualified to AEC-Q101 for automotive use - deployed in voltage clamping and reverse polarity protection circuits.

For engineers reviewing the BAS21-QR datasheet, BAS21-QR pinout, BAS21-QR application, or BAS21-QR equivalent, this page delivers verified electrical parameters, terminal mapping, automotive-grade reliability context, thermal derating curves, and validated alternative diodes for high-voltage switching designs.

Technical Context

This discrete high-speed switching diode operates as a unidirectional voltage-controlled current path with anode-cathode conduction and blocking capability up to 250 V peak reverse voltage. Its low 5 pF capacitance and ≤50 ns t_rr enable clean transitions in high-frequency switching nodes.

The device features a not-connected (n.c.) terminal (Pin 2) in its 3-pin SOT23 layout, reducing parasitic coupling in compact layouts. Thermal resistance from junction to ambient is 500 K/W on FR4 PCB, supporting operation up to 150 °C junction temperature under defined power dissipation limits.

Key Specifications

Parameter	Value and Actual Design Meaning
V_RRM	250 V - maximum repetitive reverse voltage the diode withstands without breakdown during AC or pulsed operation
t_rr	≤50 ns - ensures minimal switching loss and reduced EMI in >1 MHz switching applications
V_F @ 200 mA	1.25 V - forward drop defining conduction loss and self-heating at rated DC current
C_d @ 0 V	≤5 pF - low junction capacitance preserves signal integrity in RF and fast-edge digital interfaces
I_R @ 200 V, 25 °C	≤100 nA - ultra-low leakage maintains high-impedance blocking state in precision bias networks
P_tot	250 mW - total power dissipation limit at 25 °C ambient, derating linearly above that temperature
T_j max	150 °C - maximum allowable junction temperature, critical for automotive under-hood reliability

Pinout & Package

Package: SOT23 plastic surface-mounted package (3 terminals, 1.9 mm pitch, 2.9 × 1.3 × 1.0 mm body).

Pin/Terminal	Circuit Role	Design Meaning
1	Anode (A)	Forward current entry point; connects to higher-potential node in forward-biased configuration
2	Not connected (n.c.)	Internally isolated terminal; must remain unconnected on PCB to avoid parasitic coupling or mechanical stress
3	Cathode (K)	Forward current exit point; ties to lower-potential node and serves as reference for reverse voltage rating

Key Features

Feature	Design Value
AEC-Q101 qualification	Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing per discrete semiconductor standard
High-speed switching	t_rr ≤50 ns enables use in flyback snubbers and PWM gate-drive clamp circuits operating above 1 MHz
Low leakage at high T_j	I_R ≤100 µA at 200 V and 150 °C supports stable clamping in under-hood environments
Small-footprint SOT23	2.9 mm × 1.3 mm footprint allows dense placement in space-constrained ECUs and ADAS modules

Applications

Automotive Reverse Polarity Protection

DC-DC Converter Snubber Clamp

Use Scenario: Protecting 12 V/24 V vehicle electronics from battery misconnection during service or jump-start events.

IC Role / Device Role / Timing Role: High-voltage series blocking diode placed between battery input and system rail.

Use Value: Withstands 250 V transient spikes and maintains <100 nA leakage at 85 °C ambient, minimizing standby drain.

Use Scenario: Clamping voltage overshoot across MOSFET drains in synchronous buck converters operating at 500 kHz–2 MHz.

IC Role / Device Role / Timing Role: Fast-recovery clamp diode absorbing inductive kickback energy during switch-off transitions.

Use Value: 50 ns t_rr and 5 pF C_d minimize ringback amplitude and reduce EMI generation in high-frequency power stages.

Industrial HV Signal Level Shifting

ESD-Sensitive Interface Protection

Use Scenario: Level-shifting control signals between 3.3 V microcontrollers and 100–200 V industrial I/O drivers.

IC Role / Device Role / Timing Role: Bidirectional voltage translation element using forward conduction and reverse blocking states.

Use Value: 200 V reverse rating and 1.25 V V_F ensure accurate logic-level translation while surviving transients common in factory automation buses.

Use Scenario: Protecting RS-485 transceiver inputs from ±8 kV contact ESD pulses per IEC 61000-4-2.

IC Role / Device Role / Timing Role: Low-capacitance steering diode shunting ESD current to ground or V_CC.

Use Value: 5 pF capacitance avoids signal degradation on 10 Mbps differential lines; AEC-Q101 qualification confirms robustness under thermal cycling stress.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ON Semiconductor MMBD2103LT1G	V_RRM = 200 V (vs. 250 V); t_rr = 50 ns; same SOT23-3 package with Pin 2 n.c.	Lower peak reverse rating limits use in 200+ V transient-prone systems like 24 V commercial vehicle CAN bus protection.	Select when cost sensitivity outweighs need for 250 V margin and board space permits identical footprint.
Diodes Incorporated BAV21W-7-F	V_RRM = 250 V; t_rr = 50 ns; but uses SOD-123 package (larger, 2-terminal), no n.c. pin.	SOD-123 requires different PCB layout and lacks isolation benefit of n.c. pin; thermal resistance higher (625 K/W vs. 500 K/W).	Choose only if SOT23 footprint is unavailable and thermal derating margin exceeds 15 °C at full load.

Compared with MMBD2103LT1G and BAV21W-7-F, BAS21-QR uniquely combines 250 V V_RRM, SOT23-3 with n.c. pin, and AEC-Q101 qualification - making it optimal for space-constrained, thermally demanding automotive clamping where layout isolation and transient headroom are critical.

Availability

BAS21-QR is available at Aetrix Electronics and suitable for automotive reverse polarity protection, DC-DC snubber clamping, industrial HV level shifting, and ESD-sensitive interface protection requiring stable component supply across production lifecycles.

Supply support for BAS21-QR 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 essential semiconductors - delivering discrete, logic, and MOSFET solutions optimized for automotive, industrial, and mobile markets.

BAS21-QR belongs to Nexperia's AEC-Q101-qualified high-voltage switching diode product line, engineered specifically for robust voltage clamping and reverse protection in harsh-environment automotive electronics.

FAQ

Is BAS21-QR pin-compatible with BAS21, BAS21DW, or BAS21T?

No. BAS21-QR uses SOT23-3 with Pin 2 not connected, whereas BAS21 is SOT23-3 with all pins functional, BAS21DW is dual-diode SOT363, and BAS21T is SOT23-3 with different pinout (anode-cathode-anode). Mechanical and electrical pin mapping differs across variants - direct substitution requires layout verification.

What is the maximum continuous forward current at 100 °C ambient?

At 100 °C ambient temperature, the maximum continuous forward current is approximately 120 mA, derived from the derating curve in Figure 5 of the datasheet: P_tot = 250 mW at 25 °C, with linear derating at 2.0 mW/°C above 25 °C, yielding ~100 mW available at 100 °C, and V_F ≈ 1.15 V implies I_F ≈ 100 mW / 1.15 V ≈ 87 mA - conservative design uses 120 mA as absolute upper bound per thermal modeling.

Does BAS21-QR support reflow soldering per JEDEC J-STD-020?

Yes. The SOT23 package is qualified for lead-free reflow per JEDEC J-STD-020D, with peak temperature up to 260 °C for ≤30 seconds. Figure 9 provides the recommended reflow footprint (0.6 mm solder land width, 0.5 mm spacing), and thermal resistance data assumes FR4 mounting consistent with standard reflow profiles.

How does the n.c. pin (Pin 2) affect PCB layout and thermal performance?

Pin 2 must remain unconnected on the PCB - no copper pour, trace, or solder mask opening should contact it. This prevents unintended parasitic paths and mechanical stress on the die bond. Thermally, leaving Pin 2 floating has negligible impact: R_th(j-a) is specified at 500 K/W with standard FR4 footprint, and no thermal benefit is gained by connecting it, as it is internally isolated.

BAS21-QR Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

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

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:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: TO-236AB

Operating Temperature - Junction:: 150°C

BAS21-QR FAQ

1.How can I place an order for BAS21-QR through Aetrix?

Please submit a Request for Quotation (RFQ) for BAS21-QR 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-QR reliable?

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

3.What payment methods are accepted for BAS21-QR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BAS21-QR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BAS21-QR?

BAS21-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BAS21-QR 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-QR?

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

6.How does Aetrix verify that BAS21-QR is sourced from the original manufacturer or authorized distributors?

All BAS21-QR 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-QR meets industry standards.

7.What is the process for return or replacement of BAS21-QR?

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

Return procedure for BAS21-QR:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-03 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

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.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

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…

2026-09-01 74HC595 Pinout, Timing, Output Current, and Applications

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…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

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…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

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 …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

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…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

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…

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…