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Diodes Incorporated BCR421UFDQ-7
- Part No.:
- BCR421UFDQ-7
- Manufacturer:
- Diodes Incorporated
- Category:
- LED Drivers
- Package:
- 6-UDFN Exposed Pad
- Datasheet:
-
BCR421UFDQ-7.pdf
- Description:
- IC LED DRVR LIN PWM 350MA 6DFN
- Quantity:
- Payment:
- Shipping:
Inventory:435,674
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Product details
Overview
BCR421UFDQ-7 from Diodes Incorporated is an AEC-Q101 qualified linear LED constant current regulator (CCR) in U-DFN2020-6 package, designed for automotive low-side LED string control. It delivers 10mA ±10% preset output current, adjustable up to 350mA via external resistor REXT, supports 40V max supply voltage, features PWM-enabled dimming up to 25kHz on EN pin, and implements negative temperature coefficient current reduction for self-protection - used in dome lighting, puddle lamps, and side marker modules.
For engineers reviewing the BCR421UFDQ-7 datasheet, BCR421UFDQ-7 pinout, BCR421UFDQ-7 application, or BCR421UFDQ-7 equivalent, this page provides verified technical context, validated pin functions, real-world thermal and dimming performance data, and confirmed automotive-grade alternatives with documented functional differences.
Technical Context
The BCR421UFDQ-7 operates as a monolithic NPN emitter-follower CCR with integrated bias resistor (1.5kΩ typ) and internal current-sense resistor (95Ω typ), enabling precise current regulation without external feedback components. Its low-side enable architecture accepts 3.3V logic-level PWM signals up to 25kHz, delivering 200:1 dimming range while staying above audible frequencies.
Thermal protection is implemented via inherent negative temperature coefficient: output current decreases by −0.2%/°C above 25°C, limiting power dissipation under elevated ambient conditions. Maximum junction temperature is rated at +150°C, with RθJA = 100°C/W on 25mm² 1oz copper - requiring careful PCB copper area planning for >150mA operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 10mA ±10% preset; adjustable to 350mA with REXT - enables single-part scalability across low- and mid-current LED strings. |
| Supply Voltage | Up to 40V - supports 12V/24V automotive systems with margin for transients and LED stack voltage drop. |
| PWM Dimming | EN pin accepts 3.3V logic, 25kHz max frequency, 0.5% min duty cycle - achieves flicker-free, audio-noise-free dimming in interior lighting. |
| Thermal Coefficient | −0.2%/°C IOUT drift - provides automatic current derating above 25°C, eliminating need for external thermal shutdown circuitry. |
| Power Dissipation | 1.3W max on 25mm² 1oz Cu - defines practical current limit under typical automotive ambient (85°C) with required copper area. |
| Package | U-DFN2020-6 (2.0 × 2.0 × 0.6mm) - enables ultra-low-profile edge lighting and tight PCB spacing in space-constrained lamp housings. |
| Qualification | AEC-Q101 qualified, PPAP capable, IATF 16949 manufactured - meets automotive production traceability and reliability requirements. |
Pinout & Package
U-DFN2020-6 package: 2.0mm × 2.0mm footprint, 0.6mm profile, NiPdAu-plated terminals, moisture sensitivity level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| OUT | Regulated output current sink | Connects to cathode of LED string; carries full load current with minimal voltage drop (VOUT(MIN) = 1.4V). |
| EN | Enable input for PWM dimming | 3.3V logic-compatible input; controls internal bias transistor; enables high-frequency digital dimming without external MOSFET. |
| REXT | External current-setting resistor node | Parallel connection point with internal 95Ω resistor; sets total current via REXT value (e.g., 6.2Ω → ~150mA). |
| GND | Power ground reference | Common return path for OUT, EN, and REXT; must be low-impedance for stable current regulation. |
| N/C | No-connect terminal | Internally unconnected; left floating per design - no routing or soldering required. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated current-setting resistor | 95Ω ±10% internal RINT enables 10mA baseline operation without any external components. |
| Low-side PWM control | EN pin directly accepts microcontroller GPIO signals up to 25kHz - eliminates gate driver and level-shifter overhead. |
| Automotive thermal derating | −0.2%/°C IOUT reduction ensures safe operation at 85°C ambient without external thermal sensors. |
| Parallelable architecture | Multiple BCR421UFDQ-7 units can be paralleled to scale current beyond 350mA while maintaining matched regulation. |
| Green packaging | Halogen- and antimony-free, RoHS 3 compliant, UL 94V-0 molding compound - satisfies global automotive environmental mandates. |
Applications
| Interior Dome Lighting | Puddle Lamp Modules |
|---|---|
Use Scenario: Ambient lighting in vehicle cabin ceiling with soft white LEDs. IC Role / Device Role / Timing Role: Low-side constant current sink regulating 20–60mA LED strings, controlled via MCU PWM for fade-in/fade-out effects. Use Value: Eliminates inductor and capacitor requirements versus switching solutions, reducing BOM cost by >30% and board area by 40%. | Use Scenario: Ground-illuminating LED strips beneath door sills. IC Role / Device Role / Timing Role: Current-regulated driver for 350mA high-brightness LED strings, thermally derated during prolonged activation. Use Value: Self-protecting current reduction prevents thermal runaway when mounted near warm body panels. |
| Side Marker Lights | Edge Lighting Strips |
Use Scenario: Red/amber LED arrays meeting SAE J585E photometric requirements. IC Role / Device Role / Timing Role: Precision 10mA current source for indicator LEDs, with AEC-Q101 reliability for 15-year service life. Use Value: ±10% initial accuracy and <1%/V supply rejection ensure consistent luminance across battery voltage range (9–16V). | Use Scenario: Thin-profile accent lighting along door trim or dashboard edges. IC Role / Device Role / Timing Role: Ultra-low-height (0.6mm) current regulator enabling <1.2mm total assembly height. Use Value: U-DFN2020-6 package allows direct integration into narrow extrusions without mechanical interference. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar linear LED constant current regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BCR420UFDQ-7 | Same die, but EN pin rated for 40V (not 3.3V logic); no PWM dimming capability; internal bias resistor = 20kΩ. | Used where simple ON/OFF control suffices (e.g., static marker lights), not dynamic dimming. | Select BCR420UFDQ-7 only if PWM is unnecessary and higher enable voltage tolerance is required. |
| AL8862T-7 | Switching buck LED driver; 300mA max; requires external inductor/capacitor; 2.5MHz switching frequency. | Suitable for higher-efficiency (>90%) designs where thermal headroom is limited and EMI filtering is acceptable. | Choose AL8862T-7 only when >150mA operation exceeds BCR421UFDQ-7's thermal limits on available PCB copper area. |
Compared with BCR420UFDQ-7, BCR421UFDQ-7 adds true 3.3V logic PWM dimming and lower bias resistance - making it optimal for dynamically controlled interior lighting. Versus AL8862T-7, it trades efficiency for simplicity, size, and EMI-free operation - ideal for space- and noise-sensitive automotive zones.
Availability
BCR421UFDQ-7 is available at Aetrix Electronics and suitable for automotive interior lighting, exterior marker lamps, puddle lighting modules, and edge illumination systems requiring stable component supply, AEC-Q101 compliance, and long-term production continuity.
Supply support for BCR421UFDQ-7 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 semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions for automotive, industrial, and consumer markets.
The BCR421UFDQ-7 belongs to Diodes' automotive-qualified linear LED driver product line, engineered specifically for cost-sensitive, space-constrained, thermally demanding LED lighting applications in vehicles.
FAQ
What is the maximum continuous output current achievable with BCR421UFDQ-7?
The BCR421UFDQ-7 supports up to 350mA output current when configured with appropriate REXT and sufficient PCB copper area (≥50mm² 1oz Cu recommended). At 150mA, junction temperature remains within safe limits (<125°C) at 85°C ambient. Exceeding 350mA violates absolute maximum ratings and risks thermal failure.
Can BCR421UFDQ-7 drive multiple parallel LED strings?
Yes - the device can regulate current for a single LED string connected to its OUT pin. To drive multiple independent strings, one BCR421UFDQ-7 per string is required. Parallel devices may be used to increase total current capacity for a single string, provided matching REXT values and symmetrical PCB layout are maintained.
Is external reverse-polarity protection required for BCR421UFDQ-7?
Yes - the device has no built-in reverse-voltage protection. Diodes Incorporated recommends adding a low-VF Schottky diode (e.g., SDM10U45LP or BAS40BRW) in series with the input supply to prevent damage from battery reversal, especially in automotive environments where reverse jump-start events occur.
How does temperature affect output current accuracy in BCR421UFDQ-7?
Output current decreases linearly with rising temperature at −0.2%/°C, beginning at 25°C. At 85°C ambient, IOUT drops ~12% from nominal - a deliberate safety feature that prevents thermal runaway. This behavior is fully characterized and repeatable; no calibration is needed for automotive thermal profiles.
BCR421UFDQ-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- 6-UDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Linear
- Topology:
- -
- Internal Switch(s):
- No
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- -
- Voltage - Supply (Max):
- 18V
- Voltage - Output:
- 40V
- Current - Output / Channel:
- 350mA
- Frequency:
- -
- Dimming:
- PWM
- Applications:
- Lighting, Signage
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- U-DFN2020-6
BCR421UFDQ-7 FAQ
1.How can I place an order for BCR421UFDQ-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for BCR421UFDQ-7 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 BCR421UFDQ-7 reliable?
The price and inventory of BCR421UFDQ-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BCR421UFDQ-7 is usually 5 days.
3.What payment methods are accepted for BCR421UFDQ-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BCR421UFDQ-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BCR421UFDQ-7?
BCR421UFDQ-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BCR421UFDQ-7 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 BCR421UFDQ-7?
For technical support, including BCR421UFDQ-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BCR421UFDQ-7 requirements.
6.How does Aetrix verify that BCR421UFDQ-7 is sourced from the original manufacturer or authorized distributors?
All BCR421UFDQ-7 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 BCR421UFDQ-7 meets industry standards.
7.What is the process for return or replacement of BCR421UFDQ-7?
All BCR421UFDQ-7 units undergo pre-shipment inspection (PSI). If there is an issue with BCR421UFDQ-7, 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 BCR421UFDQ-7 part is unused and in its original packaging.
Return procedure for BCR421UFDQ-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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