BCR420UFDQ-7

BCR420UFDQ / BCR421UFDQ LINEAR LED CONSTANT CURRENT REGULATOR IN U-DFN2020-6 Description Features These Linear LED drivers are designed to meet the stringent requirements of automotive applications.  The BCR420U and BCR421U monolithically integrate transistors, diodes and resistors to function as a Constant Current Regulator (CCR) for linear LED driving. The device regulates with a preset 10mA nominal that can be adjusted with an external resistor up to 350mA. It is designed for driving LEDs in strings and will reduce current at increasing temperatures to self-protect. Operating as a series linear CCR for LED string current control, it can be used in multiple applications, as long as the maximum supply voltage to the device is < 40V. With the low-side control, the BCR421U has an Enable (EN) pin which can be pulse-width modulated (PWM) up to 25kHz by a microcontroller for LED dimming. With no need for additional external components, this CCR is fully integrated into a 2mm x 2mm x 0.6mm package (U-DFN2020-6) minimizing PCB area, off-board height, and component count.   LED Constant Current Regulator Using NPN Emitter-Follower with Emitter Resistor to Current Limit IOUT – 10mA ±10% Constant Current (Preset) IOUT up to 350mA Adjustable with an External Resistor   (BCR421U) VOUT – 40V Supply Voltage PD up to 1.7W in U-DFN2020-6 Package    0.6mm Height for Low-profile Edge Lighting Low-Side Control Enabling PWM Input < 25kHz (BCR421U) Negative Temperature Coefficient (NTC) Reduces IOUT with      Increasing Temperature Parallel Devices to Increase Regulated Current Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2) Halogen and Antimony Free. “Green” Device (Note 3) Qualified to AEC-Q101 Standards for High Reliability PPAP Capable (Note 4) Mechanical Data   Applications   Constant Current Regulation (CCR) in automotive LED lighting:  Interior and Exterior Automotive LED Lighting  Dome and Mood Lighting  Puddle Lighting  Side Marker Lights  Edge Lighting Strips EN  Case: U-DFN2020-6 Case Material: Molded Plastic. “Green” Molding Compound. UL Flammability Rating 94V-0 Moisture Sensitivity: Level 1 per J-STD-020 Terminals: Finish - NiPdAu, Solderable per MIL-STD-202, Method 208 e4 Weight: 0.018 grams (Approximate) OUT BCR420U BCR421U U-DFN2020-6 Rext (Optional) N/C GND OUT Rext N/C EN Pin Name Pin Function OUT Regulated Output Current Enable for Biasing Transistor External Resistor for Adjusting Output Current Power Ground Not Connected Internally EN Rext GND Bottom View Top View Pin-Out Internal Device Schematic GND N/C Ordering Information (Note 5) Part Number BCR420UFDQ-7 BCR421UFDQ-7 Notes: Compliance Automotive Automotive Marking 420 421 Reel Size (inches) 7 7 Tape Width (mm) 8 8 Quantity Per Reel 3,000 3,000 1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant. 2. See https://www.diodes.com/quality/lead-free/ for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free. 3. Halogen- and Antimony-free "Green” products are defined as those which contain 2.0V; VEN = 24V VOUT > 2.0V; VEN = 3.3V VOUT > 2.0V; VEN = 24V VOUT > 2.0V; VEN = 3.3V January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ Max Power Dissipation (W) Typical Thermal Characteristics BCR420/1U (@TA = +25°C, unless otherwise specified.) 600 2.0 50mm * 50mm 1oz Cu 25mm * 25mm 1oz Cu 1.2 300 200 0.4 100 10mm * 10mm 1oz Cu 0 0 50 100 100 150 1000 Copper Area (mm ) Derating Curve Rth(JA) VS 1 oz Cu Area 75 50mm * 50mm 1oz Cu 50 D=0.5 D=0.2 25 Single Pulse D=0.05 D=0.1 0 100µ 1m 10m 100m 1 10 100 1k Single Pulse Tamb=25°C 10 1 15mm * 15mm 1oz Cu 10mm * 10mm 1oz Cu 100µ 1m 100 D=0.5 75 Single Pulse 25 D=0.05 D=0.1 0 100µ 1m 10m 100m 1 10 100 1k Thermal Resistance (°C/W) 15mm * 15mm 1oz Cu D=0.2 100 1k 15mm * 15mm 1oz Cu 100 25mm * 25mm 1oz Cu Single Pulse Tamb=25°C 10 100µ 1m 10m 100m 50mm * 50mm 1oz Cu 1 10 100 1k Pulse Width (s) Transient Thermal Impedance Document number: DS39535 Rev. 3 - 2 10 10mm * 10mm 1oz Cu Pulse Width (s) BCR420UFDQ / BCR421UFDQ 1 Pulse Power Dissipation 150 50 10m 100m Pulse Width (s) Transient Thermal Impedance 125 50mm * 50mm 1oz Cu 25mm * 25mm 1oz Cu Pulse Width (s) Thermal Resistance (°C/W) 2 Temperature (°C) Maximum Power (W) Thermal Resistance (°C/W) 400 15mm * 15mm 1oz Cu 0.8 0.0 500 Rth(JA) (°C/W) 1.6 4 of 13 www.diodes.com Pulse Power Dissipation January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ Typical Electrical Characteristics BCR421U (@TA = +25°C, unless otherwise specified.) 0.20 0.20 VEN=3.3V REXT=6.2 REXT=8.2 VOUT=5.4V 0.15 REXT=10 IOUT (A) IOUT (A) 0.16 0.12 0.08 REXT= 30 REXT=15 VOUT=1.4V 0.10 0.05 0.04 VEN=3.3V REXT=open 0.000 1 2 3 4 5 6 7 8 9 10 11 12 0.00 1 10 100 REXT () VOUT (V) REXT () vs IOUT VOUT vs IOUT 0.18 o -40 C 0.06 0.16 o -40 C 0.05 IOUT (A) IOUT (A) 0.14 0.12 o 25 C 0.10 o 85 C VEN=3.3V 0.08 0.06 0.04 o 25 C o 85 C VEN=3.3V 0.03 REXT=20 REXT=6.2 0 2 4 6 8 10 0.02 0 12 VOUT (V) 2 4 6 VOUT (V) 8 10 12 VOUT vs IOUT VOUT vs IOUT 0.15 0.02 REXT=8.2 VOUT=2V REXT=6.2 REXT=10 o IOUT (A) IOUT (A) -40 C 0.01 o 85 C 0.00 0 2 4 REXT= 60 0.05 REXT= open REXT=open 8 10 12 0.00 0 1 2 3 VOUT (V) VEN (V) VOUT vs IOUT VEN vs IOUT BCR420UFDQ / BCR421UFDQ Document number: DS39535 Rev. 3 - 2 6 REXT=30 VEN=3.3V o 25 C 0.10 5 of 13 www.diodes.com 4 5 January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ Typical Electrical Characteristics BCR421U (Cont.) (@TA = +25°C, unless otherwise specified.) 0.015 3.0m o -40 C IOUT=0A o o 85 C REXT=open 2.0m IOUT (A) IEN (mA) 2.5m 1.5m 1.0m o 25 C o -40 C 25 C 0.010 o 85 C 0.005 VOUT=2V µ 500.0μ REXT=open 0.0 0 1 2 3 4 0.000 0 5 1 VEN (V) 2 3 4 5 VEN (V) VENvs IOUT VENvs IEN 0.06 0.20 o -40 C o -40 C 0.05 IOUT (A) IOUT (A) 0.15 0.04 o o 85 C 25 C 0.03 o 25 C o 0.10 85 C 0.02 0.01 0.00 VOUT=2V 0.05 VOUT=2V REXT=6.2 REXT= 20 0 1 2 3 4 5 0.00 0 VENvs IOUT BCR420UFDQ / BCR421UFDQ Document number: DS39535 Rev. 3 - 2 1 2 3 4 5 VEN (V) VEN (V) VEN vs IOUT 6 of 13 www.diodes.com January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ Typical Electrical Characteristics BCR420U (Cont.) (@TA = +25°C, unless otherwise specified.) 0.20 0.20 REXT=6.2 0.16 REXT=8.2 VOUT = 5.4V 0.15 REXT=10 IOUT (A) IOUT (A) VEN=24V 0.12 0.08 REXT=15 REXT= 30 0.04 0.10 0.05 VEN=24V REXT=open 0.00 0 1 2 3 4 5 6 7 VOUT (V) 8 VOUT=1.4V 0.00 1 9 10 11 12 10 100 REXT () REXT ()vs IOUT VOUT vs IOUT 0.18 o -40 C 0.06 0.16 o -40 C IOUT (A) IOUT (A) 0.14 0.12 o 25 C 0.10 0.04 o 25 C VEN=24V VEN=24V 0.03 REXT=20 REXT=6.2 0 2 4 6 8 10 0.02 0 12 VOUT (V) 2 4 6 VOUT (V) 8 10 12 VOUT vs IOUT VOUT vs IOUT 0.15 0.02 VOUT=2V IOUT (A) IOUT (A) 0.01 o o 85 C 4 6 0.10 REXT=open 0.05 REXT=open 8 10 12 0.00 0 5 10 15 20 25 30 VEN (V) VOUT vs IOUT Document number: DS39535 Rev. 3 - 2 REXT=30 REXT=60 VOUT (V) BCR420UFDQ / BCR421UFDQ Rext=10 VEN=24V 25 C 2 REXT=8 REXT=20 o -40 C 0.00 0 o 85 C o 85 C 0.08 0.06 0.05 VEN vs IOUT 7 of 13 www.diodes.com January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ Typical Electrical Characteristics BCR420U (Cont.) (@TA = +25°C, unless otherwise specified.) 0.015 3.0m o -40 C IOUT=0A o 2.0m o 85 C REXT=open 1.5m 1.0m o 25 C 25 C 0.010 IOUT (A) IEN (mA) 2.5m o 85 C 0.005 o -40 C VOUT=2V µ 500.0μ 0.0 0 REXT=open 5 10 15 20 25 30 35 40 0.000 0 5 10 VEN (V) 15 20 25 30 VEN (V) VENvs IEN VENvs IOUT 0.06 0.20 o -40 C o -40 C 0.05 o 85 C 25 C 0.03 0.02 VOUT=2V 0.01 0.00 0 o 25 C o IOUT (A) IOUT (A) 0.15 0.04 0.10 o 85 C VOUT=2V 0.05 REXT=6.2 REXT=20 5 10 15 20 VEN (V) 25 30 0.00 0 Document number: DS39535 Rev. 3 - 2 10 15 VEN (V) 20 25 30 VENvs IOUT VENvs IOUT BCR420UFDQ / BCR421UFDQ 5 8 of 13 www.diodes.com January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ Application Information The BCR420/1 are designed for driving low current LEDs with typical LED currents of 10mA to 350mA. They provide a cost-effective way for driving low current LEDs compared with more complex switching regulator solutions. Furthermore, they reduce the PCB board area of the solution as there is no need for external components like inductors, capacitors and switching diodes. Figure 1 shows a typical application circuit diagram for driving an LED or string of LEDs. The device comes with an internal resistor (RINT) of typically 95Ω, which in the absence of an external resistor, sets an LED current of 10mA (typical) from a VEN = 3.3V and VOUT = 1.4V for BCR421; or VEN = 24V and VOUT = 1.4V for BCR420. LED current can be increased to a desired value by choosing an appropriate external resistor, REXT. REXT (Optional) The REXT vs IOUT graphs should be used to select the appropriate resistor. Choosing a low tolerance REXT will improve the overall accuracy of the current sense formed by the parallel connection of RINT and REXT. REXT (Optional) Figure 1 Typical Application Circuit for Linear Mode Current Sink LED Driver Two or more BCR420/1s can be connected in parallel to construct higher current LED strings as shown in Figure 2. Consideration of the expected linear mode power dissipation must be factored into the design, with respect to the BCR420/1’s thermal resistance. The maximum voltage across the device can be calculated by taking the maximum supply voltage and subtracting the voltage across the LED string. VOUT = VS – VLED PD = (VOUT × ILED) + (VEN × IEN) REXT (Optional) REXT (Optional) As the output current of BCR420/1 increases, it is necessary to provide appropriate thermal relief to the device. The power dissipation supported by the device is dependent upon the PCB board material, the copper area and the ambient temperature. The maximum dissipation the device can handle is given by: PD = ( TJ(MAX) - TA) / RθJA Figure 2 Application Circuit for Increasing LED Current BCR420UFDQ / BCR421UFDQ Document number: DS39535 Rev. 3 - 2 Refer to the thermal characteristic graphs on Page 4 for selecting the appropriate PCB copper area. 9 of 13 www.diodes.com January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ Application Information (Cont.) PWM dimming can be achieved by driving the EN pin. Dimming is achieved by turning the LEDs ON and OFF for a portion of a single cycle. The PWM signal can be provided by a micro-controller or analog circuitry; typical circuit is shown in Figure 3. Figure 4 is a typical response of LED current vs. PWM duty cycle on the EN pin. PWM up to 25kHz with duty cycle of 0.5% (dimming range 200:1). This is above the audio band minimizing audible power supply noise. REXT (Optional) Figure 3 Application Circuits for LED Driver with PWM Dimming Functionality using BCR421U Figure 4 Typical LED Current Response vs. PWM Duty Cycle for 25kHz PWM Frequency (Dimming Range 200:1) BCR420UFDQ / BCR421UFDQ Document number: DS39535 Rev. 3 - 2 10 of 13 www.diodes.com January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ Application Information (Cont.) To remove the potential of incorrect connection of the power supply damaging the lamp’s LEDs, many systems use some form of reverse polarity protection. One solution for reverse input polarity protection is to simply use a diode with a low VF in line with the driver/LED combination. The low VF increases the available voltage to the LED stack and dissipates less power. A circuit example is presented in Figure 5 which protects the light engine although it will not function until the problem is diagnosed and corrected. An SDM10U45LP (0.1A/45V) is shown, providing exceptionally low VF for its package size of 1mm x 0.6mm. Other reverse voltage ratings are available from Diodes Incorporated’s website such as the SBR02U100LP (0.2A/100V) or SBR0220LP (0.2A/20V). While automotive applications commonly use this method for reverse battery protection, an alternative approach shown in Figure 6, provides reverse polarity protection and corrects the reversed polarity, allowing the light engine to function. REXT (Optional) The BAS40BRW incorporates four low VF Schottky diodes in a single package, reducing the power dissipated and maximizes the voltage across the LED stack. Figure 7 shows an example configuration for 350mA operation using BCR421U. In such higher current configurations adequate enable current is provided by increasing the enable voltage. Figure 5 Application Circuit for LED Driver with Reverse Polarity Protection REXT (Optional) Figure 6 Application Circuit for LED Driver with Assured Operation Regardless Of Polarity BCR420UFDQ / BCR421UFDQ Document number: DS39535 Rev. 3 - 2 REXT = 2.1 Figure 7 Example for 350mA Operation using BCR421U 11 of 13 www.diodes.com January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ Package Outline Dimensions Please see http://www.diodes.com/package-outlines.html for the latest version. U-DFN2020-6 A1 A3 A Seating Plane D D2 D2/2 R0 E E2 0 .10 E2/2 U-DFN2020-6 Dim Min Max Typ A 0.57 0.63 0.60 A1 0 0.05 0.03 A3 0.15 b 0.20 0.30 0.25 D 1.95 2.075 2.00 D2 1.45 1.65 1.55 e 0.65 E 1.95 2.075 2.00 E2 0.76 0.96 0.86 L 0.30 0.40 0.35 All Dimensions in mm Pin #1 ID L b e Suggested Pad Layout Please see http://www.diodes.com/package-outlines.html for the latest version. U-DFN2020-6 X C Dimensions G Y C G X X1 Y Y1 Y1 Value (in mm) 0.65 0.15 0.37 1.67 0.45 0.90 G X X1 BCR420UFDQ / BCR421UFDQ Document number: DS39535 Rev. 3 - 2 12 of 13 www.diodes.com January 2018 © Diodes Incorporated BCR420UFDQ / BCR421UFDQ IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. 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Copyright © 2018, Diodes Incorporated www.diodes.com BCR420UFDQ / BCR421UFDQ Document number: DS39535 Rev. 3 - 2 13 of 13 www.diodes.com January 2018 © Diodes Incorporated