DONGWOON DW8505A Low Dropout Linear LED Constant Current Driver IC | 100mA Adjustable / SOT23-5L / Compact Package for Backlight Application | Pin-to-Pin Replacement for BCR401W/BCR420U/DW8506

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Product Description: DW8505A is a fast-switching low dropout linear LED constant current driver IC launched by DONGWOON Korea. It features 5~40V wide input voltage, maximum 100mA adjustable output current, built-in thermal foldback protection and 0~100% PWM dimming function. The output current is set by a single external resistor with minimal peripheral circuits and low EMI noise. It is ideally designed for LED lamps, indicator & decorative lighting, panel backlight, RGB backlight, automotive lighting and general constant current source applications. It can directly replace mainstream models including BCR401W, BCR420U and DW8506 with higher constant current accuracy, lower dropout voltage and superior reliability.

DW8505A Linear LED Constant Current Driver IC Core Advantages

● Wide input voltage 5~40V, compatible with 12V/24V industrial and backlight power supply systems

● 0~100mA adjustable output current, precise current setting via single resistor, constant current accuracy ±3%

● Ultra-low dropout voltage: 0.1V max @ 60mA, lower heat generation and higher efficiency

● Built-in thermal foldback protection, current automatically reduces under high temperature for long-term reliable operation

● PWM dimming support (≤30kHz), flicker-free precise dimming from 0 to 100%

● Only one external resistor required, simplified circuit design, lower cost and easy PCB layout

● Compact SOT23-5L package, small footprint, good heat dissipation and easy for SMT production

● Low EMI interference, easily pass various safety and EMC compliance tests

DW8505A Key Electrical Parameters | Specifications

DW8505A Pinout & Package Dimension | Pin Diagram

DW8505A Internal Block Diagram | Internal Structure

DW8505A Typical Application Circuit | Reference Design

DW8505A Application Fields | Applicable Industries

● LED bulbs, residential lighting and small lighting equipment

● Indicator signs, advertising signage and decorative LED lighting

● Panel displays, home appliance panels and general backlight lighting

● RGB backlight, colorful lighting and ambient light drivers

● Constant current modules matched with DC/DC & AC/DC power supplies

● Automotive interior lights, daytime running lights, signal lights and vehicle lighting

● General constant current sources, industrial control and instrumentation power supply

Compatible Replacement Models & Advantages Comparison

DONGWOON DW8505A supports direct pin-to-pin replacement for: DW8506, BCR401W, BCR420U

● Advantage 1: Wider operating voltage range 5~40V, covering more industrial and backlight scenarios

● Advantage 2: Lower dropout voltage (0.1V @ 60mA), higher efficiency and less heat dissipation

● Advantage 3: Built-in thermal foldback protection, higher reliability compared with competitors without protection

● Advantage 4: ±3% constant current accuracy, stable output against voltage and temperature fluctuation

● Advantage 5: PWM dimming supported while BCR401W does not, broader application coverage

Parameter Comparison with Similar Products | Replacement Comparison

Demo Board Test Comparison

	DW8505A	DW8506	BCR401W	BCR420U
EVB
RSET (20mA)	36Kohm	6.04Kohm	80ohm	100ohm

Output Current Characteristics vs Output Voltage

Test Condition: Input 12V, Output Current 20mA

DW8505A and DW8506 enable multiple LED modules to be installed on a single 12VDC power supply, thanks to their much lower dropout voltage compared with BCR401W and BCR420U.

IC Temperature Characteristics vs Output Voltage

Test Condition: Input 12V, Output Current 20mA

Output Current Characteristics vs Ambient Temperature

Test Condition: Input 12V, Output Current 20mA, Temperature Range -45℃~145℃

When the junction temperature of DW8505A and DW8506 reaches 125℃, thermal foldback protection activates and reduces the output current to 1/4 of the set value, which effectively lowers chip temperature.

BCR420U and BCR401W have no built-in thermal protection circuit.

Output Current Characteristics vs EN Pin Voltage

Test Condition: Input 40V, Output Current 20mA, Variable EN Pin Voltage

DW8505A maintains stable 20mA constant current output with varying EN pin voltage, while BCR420U cannot keep constant output current.

Within EN pin voltage range 5V~35V, the output current variation of DW8505A is only -0.09%, compared with 15.38% of BCR420U.

DONGWOON Korea Linear Constant Current Driver Solution Recommendation

	DW8501	DW8502	DW8505A	DW8506	DW8506A	DW3505A
Input Voltage (V)	5~40	5~40	5~40	6.5~40	6.5~40	5~40
Output Current	Adjustable up to 1.5A	Adjustable up to 2.5A	Adjustable up to 100mA	Adjustable up to 100mA	Fixed 60mA	Adjustable up to 300mA
Dropout Voltage	Max.0.3V @ 300mA	Max.1V @ 1A	Max.0.1V @ 60mA	Max.0.5V @ 50mA	Max.0.6V @ 60mA	Max.0.2V @ 60mA
Dimming Function	PWM	PWM	PWM	--	--	PWM
Protection	Thermal Foldback	Thermal Foldback	Thermal Foldback	Thermal Foldback	Thermal Foldback	Thermal Foldback
Package	SOT223-5L/TO252-5L	TO263-5L/TO220-5L	SOT23-5L	SOT23-5L	WLCSP	SOT89-5L
Typical Circuit

Authorized Distributor & Service

GS Micro Semiconductor (Shenzhen) Co., Ltd. is the official authorized distributor of DONGWOON Korea. We focus on promoting linear constant current drivers and power management ICs, providing complete datasheets, application solutions, sample testing and professional technical after-sales support to accelerate customers' mass production.

Official Website: https://www.gs-micro.com