DongWoon Primary Agent DC to DC linear constant current drive IC DW3505A
- Model：
- DW3505A
- Brand：
- DongWoon
- Batch No：
- DW3505A,BCR320U,BCR420U
- Desc：
- As an authorized Level 1 distributor of DONGWOON ANATECH, GSMICRO supplies genuine DW3505A in stock. This part is fully pin-to-pin compatible and can replace AMC7135, QX7135, BCR420U and other equivalent models.
- Stock：
- 250000 只
DONGWOON DW3505A Low Dropout Linear LED Driver IC | 300mA Adjustable, SOT89-5L, Automotive & Industrial Indicator Lighting | Replace AMC7135/QX7135/BCR420U
The DW3505A from DONGWOON ANATECH is a wide input voltage, low dropout linear constant current LED driver IC. It supports 5V to 40V input and delivers 0~300mA adjustable output current, integrating a power MOSFET and thermal fold-back protection. Packaged in SOT89‑5L, it is pin-to-pin compatible with AMC7135, QX7135, BCR320U, BCR420U and other popular models. Ideal for automotive interior lighting, signage, RGB backlighting, and other EMI‑sensitive applications that demand low dropout. Compared to traditional solutions, the DW3505A offers ultra-low dropout (0.2V@60mA) and PWM dimming, significantly reducing heat generation and improving system reliability in 12V/24V systems.
DW3505A Ordering Information & Package Specifications
| Part Number | Marking | Package | Packaging Type |
|---|---|---|---|
| DW3505A | DW3505A | SOT89-5L | 2500pcs/Reel |
DW3505A Key Features & Advantages
● Wide input voltage 5~40V, perfect for 12V/24V automotive and industrial power supplies
● Adjustable output current 0~300mA, set by a single resistor, ±5% constant current accuracy
● Ultra-low dropout: 0.2V max @60mA, lower heat dissipation, higher efficiency
● Built-in thermal fold-back protection (140°C threshold), auto current reduction, safer long-term operation
● PWM dimming support (≤30kHz), 0~100% flicker-free precise dimming
● Only one external resistor required, extremely simple BOM and PCB layout
● SOT89-5L standard package, small size, good thermal performance, easy SMT assembly
● No EMI interference, easily passes safety and EMC tests
DW3505A Key Electrical Specifications | Datasheet Parameters
| Parameter | Typical Value | Unit |
|---|---|---|
| Input Voltage | 5~40 | V |
| Output Current | 0~300 | mA |
| Dropout Voltage | 0.2@60mA | V |
| Constant Current Accuracy | ±5% | -- |
| Thermal Fold-back Threshold | 140 | ℃ |
| Dimming Method | PWM (≤30kHz) | -- |
| Package | SOT89-5L | -- |
DW3505A Pin Configuration & Package Dimensions | Pinout Diagram
| Pin No. | Pin Name | Description |
|---|---|---|
| 1 | RS | Output current set, connect resistor to GND |
| 2 | GND | Ground |
| 3 | EN | Enable & PWM dimming input, active high, recommended ≤30kHz |
| 4 | OUT | LED constant current output |
| 5 | VDD | Power supply input |
DW3505A Internal Block Diagram | Architecture
DW3505A Typical Application Circuits | Reference Designs
The circuits above cover 12V/24V conventional driving, PWM dimming, multi-LED series connection, and high‑voltage input step‑down extended solutions. Connect a PWM signal to the EN pin for stepless dimming, and set the current with an RS resistor – extremely simple external components.
DW3505A Applications | Target Markets
● LED bulbs, residential lighting, small luminaires
● Signage, advertising displays, decorative LED lighting
● Flat panel displays, appliance panels, general backlighting
● RGB backlighting, color‑changing lighting, mood lighting
● DC/DC, AC/DC companion constant current sources, current regulators
● Automotive interior lights, daytime running lights, signal lamps, vehicle lighting
● General constant current sources, industrial controls, instrument constant current supply
DONGWOON Linear Constant Current LED Driver Solutions
| Model / Parameter | 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 | ≤1.5A adjustable | ≤2.5A adjustable | ≤100mA adjustable | ≤100mA adjustable | Fixed 60mA | ≤300mA adjustable |
| Dropout | Max.0.3V@300mA | Max.1V@1A | Max.0.1V@60mA | Max.0.5V@50mA | Max.0.6V@60mA | Max.0.2V@60mA |
| Dimming | PWM | PWM | PWM | -- | -- | PWM |
| Protection | Thermal fold-back | Thermal fold-back | Thermal fold-back | Thermal fold-back | Thermal fold-back | Thermal fold-back |
| Package | SOT223-5L/TO252-5L | TO263-5L/TO220-5L | SOT23-5L | SOT23-5L | WLCSP | SOT89-5L |
| Typical Circuit |  |  |  |  |  |  |
DW3505A Compatible Replacement Models & Advantage Comparison
DONGWOON DW3505A is a direct PIN‑TO‑PIN replacement for: AMC7135, QX7135, BCR320U, BCR420U.
● Advantage 1: Wider operating voltage 5~40V, covers more automotive and industrial applications
● Advantage 2: Lower dropout (0.2V@60mA), higher efficiency, lower heat generation
● Advantage 3: Built‑in thermal fold‑back protection – most competitors lack this, improving reliability
● Advantage 4: ±5% constant current accuracy, more stable over temperature and voltage variations
● Advantage 5: Supports higher PWM dimming frequency, smoother flicker‑free dimming
DW3505A vs. Competing Models – Parameter Comparison
| Parameter | DW3505A | BCR320U | BCR420U | Advantage Description |
|---|---|---|---|---|
| Brand | DONGWOON | Infineon | Infineon | Stable OEM supply |
| Operating Voltage | 5~40V | ~25V | ~40V | Wider voltage range |
| Max Current | 300mA | 250mA | 150mA | Higher output capability |
| Dropout Voltage | 0.2V@60mA | 1.4V | 1.4V | Lower dropout, higher efficiency |
| Thermal Protection | Yes | No | No | Safer under high temperature |
| Current Accuracy | ±5% | -- | ±10% | Higher precision & stability |
Brand & Distribution Service
GSMicro Semiconductor (Shenzhen) Co., Ltd. is an official authorized distributor of DONGWOON (Korea). We focus on linear constant current LED drivers and power management ICs, providing complete datasheets, application solutions, sample testing, and technical support to help customers achieve fast mass production. With warehouses in Shenzhen and Shanghai, we offer fast shipping.
Official website: https://www.gs-micro.com
Frequently Asked Questions (FAQ)
Can the DW3505A directly replace AMC7135 or QX7135?
What is the PWM dimming frequency limit?
What is the thermal fold-back trigger temperature?
How can I request samples or get volume pricing?
DW3505A vs BCR320U/BCR420U Performance Parameter Test | DONGWOON Low Dropout Linear Constant Current Driver IC Selection Advantages
Keywords:DW3505A, DONGWOON Korea, BCR320U, BCR420U, DW3505A replace BCR320U, DW3505A compare BCR420U, Linear Constant Current Driver IC, Low Dropout Constant Current IC, PWM Dimming LED Driver IC, Automotive Lighting Constant Current Chip, Vehicle LED Decorative Light Driver, Low Power Constant Current IC, LED Driver With Thermal Protection, DW3505A Parameters, BCR320U Parameter Comparison
Overview:This article conducts a complete performance parameter test on DONGWOON DW3505A versus Infineon BCR320U and BCR420U. It makes a horizontal comparison from multiple dimensions including operating voltage, output current, dropout voltage, temperature protection, current accuracy, PWM dimming, high and low temperature characteristics. The test results prove that DW3505A features ultra-wide voltage range, ultra-low dropout voltage, built-in thermal derating protection and high-precision current stability. It is an ideal alternative to BCR320U/BCR420U for automotive lighting, LED decorative lights, backlight driving and industrial constant current solutions.
DW3505A vs BCR320U/BCR420U Full Parameter Comparison Table
| Item | DW3505A | BCR320U | BCR420U | Remark |
| Manufacturer | DONGWOON | Infineon | Infineon | - |
| Operating Voltage | 5V~40V | ~25V | ~40V | - |
| Package Dimension | SOT89-5L (4.5mm X 4.5mm X 1.5mm) | SC74-3D (2.9mm X 2.5mm X 1.1mm) | SC74-6L (2.9mm X 2.5mm X 1.1mm) | - |
| PWM Dimming | Available (PWM input up to 20KHz) | Available (PWM input up to 10KHz) | Available (PWM input up to 10KHz) | - |
| Output Current | Up to 300mA Adjustable | Up to 250mA Adjustable | Up to 150mA Adjustable | Depends on package surface temperature and heat dissipation condition |
| Thermal Protection | Yes | No | No | Required for high-temperature resistant LED modules |
| Output Dropout Voltage | 0.1V@60mA | 1.4V (Iout>18mA) | 1.4V (Iout>18mA) | DW3505A supports more LED modules installed on SMPS |
| Temperature Drift | Under ±2% (at 60mA) | - | ±10% (at 52mA) | Temperature range: -40℃~145℃ |
| Iout Variation With VEN | Under ±0.5% (VEN 5~40V) | - | 40mA~52mA (VEN 5V~25V) | BCR320U requires strict VEN voltage selection |
| Current Accuracy | ±5% (at 60mA) | - | ±10% (at 10mA) | - |
Influence of High & Low Temperature on DW3505A Constant Current Output Characteristics
Test Condition: Input 12V, Output 3V, Output Current 60mA/150mA, Temperature Range -40℃~150℃
DW3505A Constant Current Output Accuracy Test Data
Output Current Accuracy @60mA: -1.3% ~ 0.68%
Output Current Accuracy @150mA: -1.52% ~ 1.31%
When DW3505A operates at 140℃~150℃ high temperature range and activates thermal derating protection, the output current will automatically drop to 1/4 of the normal value, ensuring chip and lamp safety.
BCR320U has no built-in thermal protection circuit, which brings burnout risk under high-temperature operation and is not suitable for harsh high-temperature working conditions of vehicle applications.
Influence of EN Pin Voltage Fluctuation on DW3505A Output Current Stability
DW3505A Test Condition: Input Voltage 30V, EN Voltage 0V~30V, Output Voltage 2V, RSET Configuration, Ta=25℃
BCR320U Test Condition: IOUT=F(VEN), VOUT=2V, REXT=3Ω, Refer to Datasheet Page 16
DW3505A can work normally when EN pin voltage is higher than 2V, with output current accuracy up to ±0.01%. It features excellent voltage adaptability and is ideal for vehicle power supply environment with large voltage fluctuation.
The output current of BCR320U fluctuates obviously with EN pin voltage. Its current stability and controllability are far lower than DW3505A, which is not conducive to high-precision LED lighting solution design.
Summary of Core Selection Advantages: DW3505A vs BCR320U/BCR420U
1. DW3505A supports 5~40V ultra-wide operating voltage, higher than BCR320U upper limit 25V. It perfectly adapts to harsh power supply scenarios of vehicle and industrial equipment, more friendly for automotive lighting solution selection.
2. DW3505A ultra-low dropout voltage only 0.1V@60mA, much lower than 1.4V of BCR series. It generates less heat and achieves higher power conversion efficiency, suitable for multi-LED series module design.
3. DW3505A is built-in with thermal derating protection, while BCR320U/BCR420U have no thermal protection function. DW3505A owns higher reliability and burnout resistance under long-term high-temperature continuous operation.
4. DW3505A current accuracy reaches ±5%, its stability under temperature and voltage fluctuation is far better than BCR420U with ±10% accuracy, delivering more uniform and consistent light brightness.
5. DW3505A supports up to 20kHz PWM dimming with smooth flicker-free dimming performance, better than 10kHz upper limit of BCR series, suitable for interior ambient light and backlight fine dimming applications.
DW3505A Selection FAQ
Q1: Can DW3505A directly replace BCR320U?
A1: Direct pin-to-pin compatible replacement available. DW3505A matches package size, features wider adjustable current range, ultra-low dropout voltage and built-in thermal protection, with overall performance surpassing BCR320U comprehensively.
Q2: Which one provides better PWM dimming effect, DW3505A or BCR420U?
A2: DW3505A supports 20kHz high-frequency PWM dimming, far exceeding 10kHz limit of BCR420U. It achieves smoother dimming transition and better flicker-free visual experience.
Q3: Can BCR320U be used in automotive high-temperature scenarios without thermal protection?
A3: Not recommended. BCR320U/BCR420U lack built-in thermal protection circuit, easy to burn out under long-term operation in summer high-temperature vehicle environment. DW3505A comes with thermal derating protection, more suitable for harsh working conditions of automotive lighting.
Q4: What is the biggest advantage of DW3505A compared with BCR series?
A4: Five core advantages: 40V ultra-high withstand voltage, 0.1V ultra-low on-state dropout voltage, tiny current drift under high and low temperature, built-in thermal protection and high-frequency PWM dimming. It is the preferred alternative device for industrial and vehicle LED constant current driver applications.
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