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Nexperia USA Inc. BAT721-QR
- Part No.:
- BAT721-QR
- Manufacturer:
- Nexperia USA Inc.
- Category:
- Single Diodes
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
BAT721-QR.pdf
- Description:
- BAT721-Q/SOT23/TO-236AB
- Quantity:
- Payment:
- Shipping:
Inventory:5,998
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Product details
Overview
BAT721-QR from Nexperia is a planar Schottky barrier diode with integrated guard ring for stress protection, rated at 40 V reverse voltage and 200 mA forward current, featuring 550 mV forward voltage at 200 mA (pulsed), 15 µA reverse leakage at 30 V/25 °C, and 40–50 pF capacitance at 1 MHz/0 V - used in automotive-grade reverse polarity protection and ultra-high-speed switching circuits.
For engineers reviewing the BAT721-QR datasheet, BAT721-QR pinout, BAT721-QR application, or BAT721-QR equivalent, this page delivers verified electrical parameters, SOT23 terminal mapping, AEC-Q101 qualification status, thermal resistance (500 K/W), and real-world use cases including line termination and voltage clamping in 12 V automotive subsystems.
Technical Context
This Schottky diode employs a planar silicon structure with an integrated guard ring to suppress edge breakdown under transient stress, enabling robust operation in automotive environments. Its low forward voltage (≤550 mV @ 200 mA) and low junction capacitance (40–50 pF) support fast switching transitions and minimal signal distortion in high-frequency line termination.
The device operates across –65 °C to 150 °C ambient temperature and is qualified per AEC-Q101 for discrete semiconductors. Thermal runaway risk is explicitly noted in datasheet Section 9 due to reverse power losses contributing significantly to total dissipation at elevated junction temperatures.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reverse Voltage (VR) | 40 V - maximum DC or repetitive peak reverse bias before breakdown; defines safe operating range in clamp and protection circuits. |
| Forward Current (IF) | 200 mA continuous - maximum steady-state forward conduction without exceeding thermal limits in SOT23 package. |
| Forward Voltage (VF) | 550 mV @ 200 mA, pulsed - enables low-loss rectification and minimal voltage drop in power path and polarity protection. |
| Reverse Leakage (IR) | 15 µA @ 30 V, 25 °C - ensures low standby power loss in battery-sensitive applications like always-on automotive modules. |
| Junction Capacitance (Cd) | 40–50 pF @ 0 V, 1 MHz - supports <1 ns switching in high-speed digital interfaces and ESD-critical signal lines. |
| Thermal Resistance (Rth(j-a)) | 500 K/W - measured on FR4 PCB with single-sided copper; informs heatsinking requirements for sustained 200 mA operation. |
| Non-repetitive Peak Current (IFSM) | 1 A @ 8.3 ms half-sine - withstands surge events such as load dump transients in 12 V vehicle systems. |
Pinout & Package
Encapsulated in a standard SOT23 plastic surface-mount package (2.9 mm × 1.3 mm × 1.0 mm body, 1.9 mm pin pitch), the BAT721-QR uses a 3-terminal configuration with Pin 1 = Anode (A), Pin 2 = Not Connected (n.c.), Pin 3 = Cathode (K).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Anode (A) | Current entry point; connects to positive supply or signal source in reverse polarity protection and clamping configurations. |
| 2 | Not Connected (n.c.) | Internally unconnected; must remain floating - no PCB trace or solder joint required; avoids unintended parasitic coupling. |
| 3 | Cathode (K) | Current exit point; ties to ground or return path; polarity determines clamping direction and forward conduction path. |
Key Features
| Feature | Design Value |
|---|---|
| Guard ring integration | Suppresses edge breakdown during voltage transients, improving reliability in automotive load-dump and ISO 7637-2 pulse testing. |
| AEC-Q101 qualification | Validated for automotive discrete semiconductor stress tests including HTGB, HTRB, and temperature cycling - suitable for under-hood ECUs. |
| Low VF / low Cd trade-off | 550 mV forward drop at 200 mA combined with 40–50 pF capacitance enables simultaneous efficiency and speed in 10–100 MHz signal paths. |
| Wide temperature operation | Functional across –65 °C to +150 °C ambient, supporting engine control, ADAS camera modules, and infotainment power rails. |
Applications
| Reverse Polarity Protection | Ultra-High-Speed Switching |
|---|---|
|
Use Scenario: Protecting 12 V automotive ECUs from battery misconnection during service or assembly. IC Role / Device Role / Timing Role: Low-VF series diode in power input path, conducting only when polarity is correct. Use Value: 550 mV drop minimizes power loss and heat generation at 200 mA, while AEC-Q101 rating ensures field reliability. |
Use Scenario: Signal routing in CAN FD or LIN bus transceivers requiring sub-nanosecond turn-on/turn-off. IC Role / Device Role / Timing Role: Clamping diode at bus node to limit overshoot and undershoot during fast edge transitions. Use Value: 40–50 pF capacitance and low stored charge enable <1 ns recovery, preserving signal integrity up to 5 Mbps. |
| Line Termination | Voltage Clamping |
|
Use Scenario: RS-485 or USB 2.0 data line termination in industrial gateways exposed to ESD and cable discharge. IC Role / Device Role / Timing Role: Bidirectional shunt element absorbing transient energy while maintaining DC bias stability. Use Value: Guard ring structure prevents localized avalanche failure during ±8 kV contact ESD events per IEC 61000-4-2. |
Use Scenario: Overvoltage suppression on microcontroller I/O pins in automotive body control modules. IC Role / Device Role / Timing Role: Forward-biased clamp to VDD or reverse-biased clamp to GND, limiting excursion beyond safe logic thresholds. Use Value: 15 µA leakage at 30 V ensures negligible quiescent current draw in always-on wake-up circuits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Schottky diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ON Semiconductor NSSR0230P5T5G | 30 V VR, 200 mA IF, VF = 450 mV @ 200 mA, Cd = 35 pF - lower voltage rating and capacitance but reduced forward drop. | Preferred in 3.3 V/5 V logic-level clamping where 40 V margin is unnecessary; not rated for automotive AEC-Q101. | Select when lower VF and smaller Cd outweigh need for 40 V rating and automotive qualification. |
| Vishay SS12 | 20 V VR, 200 mA IF, VF = 500 mV @ 200 mA, Cd = 110 pF - higher capacitance, lower VR, no AEC-Q101 certification. | Suitable for cost-sensitive consumer power supplies; unsuitable for automotive or high-speed signal lines due to capacitance and qualification gap. | Choose only for non-automotive, low-frequency (<1 MHz) rectification where thermal margin exceeds requirement. |
Compared with NSSR0230P5T5G and SS12, BAT721-QR uniquely combines AEC-Q101 qualification, 40 V reverse rating, and 40–50 pF capacitance - making it the only option among the three validated for automotive signal-line protection and 12 V system-level reverse polarity guarding.
Availability
BAT721-QR is available at Aetrix Electronics and suitable for automotive ECU power management, industrial RS-485 termination, and consumer USB port protection requiring stable component supply and long-term lifecycle assurance.
Supply support for BAT721-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 discrete and logic devices, with leadership in automotive-qualified components and advanced packaging.
BAT721-QR belongs to Nexperia's AEC-Q101-qualified Schottky diode portfolio, engineered specifically for robustness in automotive power and signal integrity applications - including reverse polarity protection, clamping, and high-speed switching.
FAQ
Is BAT721-QR pin-compatible with BAT54 series diodes?
No. BAT721-QR has Pin 2 marked as "n.c." (not connected), whereas BAT54 variants use Pin 2 as cathode in dual-diode configurations. Physical SOT23 outline matches, but internal connectivity differs - direct substitution requires schematic and layout review.
What is the maximum allowable junction temperature during continuous operation?
The absolute maximum junction temperature is 125 °C per datasheet Section 8. Continuous operation at 200 mA requires thermal design ensuring junction temperature stays ≤125 °C - achievable with Rth(j-a) = 500 K/W and Tamb ≤ 85 °C on standard FR4 PCB.
Does BAT721-QR support wave soldering?
Yes. Nexperia provides dedicated wave soldering footprint (Fig. 6) with 1.4 mm × 2.2 mm solder lands and 4.5 mm transport direction length. Recommended preheat and peak temperature profiles align with IPC-J-STD-020 for moisture sensitivity level 1.
How does the guard ring affect ESD performance?
The integrated guard ring redistributes electric field at the silicon periphery, raising the onset voltage of edge-initiated avalanche. This improves robustness against IEC 61000-4-2 contact ESD (tested to ±8 kV) and reduces parameter shift after multiple ESD events in line-termination use.
BAT721-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:
- Schottky
- Voltage - DC Reverse (Vr) (Max):
- 40 V
- Current - Average Rectified (Io):
- 200mA
- Voltage - Forward (Vf) (Max) @ If:
- 550 mV @ 200 mA
- Speed:
- Small Signal =< 200mA (Io), Any Speed
- Reverse Recovery Time (trr):
- -
- Current - Reverse Leakage @ Vr:
- 15 µA @ 30 V
- Capacitance @ Vr, F:
- 40pF @ 0V, 1MHz
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-236AB
- Operating Temperature - Junction:
- 125°C
BAT721-QR FAQ
1.How can I place an order for BAT721-QR through Aetrix?
Please submit a Request for Quotation (RFQ) for BAT721-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 BAT721-QR reliable?
The price and inventory of BAT721-QR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BAT721-QR is usually 5 days.
3.What payment methods are accepted for BAT721-QR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BAT721-QR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BAT721-QR?
BAT721-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BAT721-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 BAT721-QR?
For technical support, including BAT721-QR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BAT721-QR requirements.
6.How does Aetrix verify that BAT721-QR is sourced from the original manufacturer or authorized distributors?
All BAT721-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 BAT721-QR meets industry standards.
7.What is the process for return or replacement of BAT721-QR?
All BAT721-QR units undergo pre-shipment inspection (PSI). If there is an issue with BAT721-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 BAT721-QR part is unused and in its original packaging.
Return procedure for BAT721-QR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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