DW8505A General Description：
The DW8505A is an instant On/Off LED driver for low power LED applications. At DW8505A output stage, one regulated current port is designed to provide a uniform and constant current sink for driving LEDs within a large range of VF variations.
DW8505A easily provides users a consistent current source. User may adjust the output current from up to 100mA through an external resistor RS, which gives users flexibility in controlling the light intensity of LEDs. In addition, users can precisely adjust LED brightness from 0% to 100% via output enable (EN) with Pulse Width Modulation.
DW8505A also guarantees that LEDs can be cascaded to maximum 40V at the output port.
DW8505A Applications :
• LED light bulbs
• Signage and decorative LED lighting
• General lighting of flat panel displays
• RGB backlighting LED driver
• Current stabilizer with DC/DC or AC/DC
• Automotive lighting
• General purpose constant current source
DW8505A Features：
● The DW8505A is Constant output current invariant to supply and load voltage change.
● The DW8505A is 5V to 40V supply voltage
● The DW8505A is Up to 100mA adjustable regulated output current
● The DW8505A is Built-in thermal derating circuit
● The DW8505A is Available PWM dimming control
● The DW8505A is Output current adjusted through an external resistor
●The DW8505A is SOT-23-5L(2.92x 2.8x 1.3(mm)) Package
DW8505A Pin placement and IC dimension ：
DW8505A Pin Description
PIN(DW8505A)
| DW8505A Pin Name | DW8505A Description |
1
| EN
| Output stage enable control pin. High enable the OUT pin. Dimming control is possible by PWM(Pulse width modulation).Typically, It operates under 30kHz. |
| 2 | GND
| Ground
|
| 3 | RS
| Output current set input. Connect a resistor from RS to GND to set the LED bias current. |
| 4 | VDD
| Supply voltage input.
|
| 5 | OUT
| Output pin. Sink current is decided by the current on RSET connected to RS. |
DW8505A Block Diagram
The DW8505A Typical Applications circuit
DW8505A vs BCR401W/420U
| DW8505A
| DW8506 | BCR401W | BCR420U | Remark |
Vender | DONGWOON
| DONGWOON | infineon | infineon | - |
Operating voltage | 5V~40V | 6.5V~40V | ~18V | ~40V | - |
PKG Size | SOT23-5L
(2.9mm X 2.8mm X 1.3mm)
| SOT23-5L
(2.9mm X 2.8mm X 1.3mm) | SOT343-4L (2.0mm X 2.1mm X 0.9mm) | SC74-6L
(2.9mm X 2.5mm X 1.1mm) | - |
PWM Dimming | O
(PWM input up to 20KHz)
| X | X | O
(PWM input up to 10KHz) | PWM input up to 20kHz frequency(DW8505A) |
Output Current | Up to 150mA Adjustable
| Up to 150mA
Adjustable | Up to 60mA
Adjustable | Up to 150mA
Adjustable | The Output current is Required set by considering The actual PKG’ surface temperature |
Temperature Protection | O
| O | X | X | LED module is required high Temperature protection |
Dropout Voltage | 0.1V@60mA
| 0.5V@50mA | 1.2V(Iout>8mA) | 1.4V (Iout>1.8mA) |
DW8505A(06) helps to install Many LED modules on a SMPS |
Variation by Temp. | Under ±1% (VEN 5V~40V) |
Under ±1% (VEN 5V~40V) | - | ±10%
(at 52mA) | Temperature -40℃~145℃ |
Iout Variation
At VEN Voltage | Under ±0.5% (VEN 5~40V) | - | - | 40mA~52mA
(VEN 5V~25V) |
Infinieon IC needs to select VEN Voltage |
Accuracy | ±3%(at 60mA)
| ±5% (at 60mA) | ±10%(at 20mA) | ±10% (at 10mA) | - |
Test DEMO Board
| DW8505A | DW8506 | BCR401W | BCR420U |
| EVB | 
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| 
| 
|
| RSET(20mA) | 36Kohm
| 6.04Kohm
| 80ohm
| 100ohm
|
DW8505A Output current characteristics by output voltage change
Test Condition：Vin12V, Iout 20mA Setting
| DW8505A
| DW8506
| BCR420U
| BCR401W
| Note. |
Dropout Voltage | 0.2V
| 0.3V
| 1V
| 1.2V
| Standard of VOUT 90%
|
DW8505A（DW8506）helps to install many LED modules on the same 12Vdc SMPS ( Because the dropout voltage of DW8505A, DW8506 are lower than BCR401W,BCR420U)
DW8505A IC Temperature characteristics by output voltage change ：
Test Condition : Vin12V, Iout 20mA Setting
IC temperature characteristics by Vout values( customer’s use of conditions : Vout Max. 9.4V )
| DW8505A
| DW8506
| BCR420U
| BCR401W
|
| IC Temp.(°C) | 53.7°C
| 54.3°C
| 58.4°C
| 51.2°C
|
DW8505A Output current characteristics by temperature change
Test Condition : Vin12V, Iout 20mA, Vout LED Vf Min.~Max. Setting. Temp. -45°C~145°C.
Current Accuracy：
LED Vf
| DW8505A
| DW8506
| BCR420U
| BCR401W
| Note. |
2.6V
| 4.53 ~ -5.84%
| -1.82 ~ 3.41%
| 10.64 ~ -20.39%
| 14.89 ~ -17.30%
| DW8505A/06 Thermal Derating O |
3.2V
| 4.42 ~ -5.70%
| -1.81 ~ 3.39%
| 10.56 ~ -20.42%
| 14.81 ~ -18.63%
|
As DW8505A, DW8506 operate the thermal derating protection at 125 °C, output current values reduce to ¼ .
As a result, It can drop IC’s heating level.
DW8505A/06 have the deviation(variation) less than ±6%, While BCR401W/420U have the deviation(variation) less than ±20%.
DW8505A Output current characteristics by EN pin voltage change：
Test Condition：Vin40V, Iout 20mA Setting, EN pin variable Voltage
DW8505A is able to output constant current, 20mA as variable EN pin voltage, but BCR420U does not output the constant current value.
(In the case of BCR420U, it separately needs to set EN pin voltage values)
DW8505A has output current variations up to -0.09% on EN pin 5V~35V while BCR420U has output current variations up to 15.38%.
DONGWOON Linear Solution ( Constant Current Regulator) ：
| DW8501
| DW8502
| DW8505A
| DW8506
| DW8506A
| DW3505A
|
Vin (min/max(V)) | 5V to 40V
| 5V to 40V
| 5V to 40V
| 6.5V to 40V
| 6.5V to 40V
| 5V to 40V
|
Output Current(mA) | Up to 1.5A adjustable
| Up to 2.5A adjustable
| Up to 100mA adjustable
| Up to 100mA adjustable
| Fixed 60mA
| Up to 300mA adjustable
|
Dropout Voltage
| Max.0.3V @ ILED=300mA
| Max. 1V @ ILED=1A
| Max. 0.1V @ ILED=60mA
| Max. 0.5V @ ILED=50mA
| Max. 0.6V @ ILED=60mA
| Max. 0.2V @ ILED=60mA
|
Dimming
| PWM
| PWM
| PWM
| -- | -- | PWM
|
Protection Function | Thermal derating
| Thermal derating
| Thermal derating
| Thermal derating
| Thermal derating
| Thermal derating
|
Package Options | SOT223-5L (6.5 x 3.5 x 1.8) TO252-5L (6.5 x 5.5 x 2.3) | TO263-5L (10.16x15.35x4.57) TO220-5L (10.1x28.85x4.57) | SOT23-5L (2.9 x 2.8 x 1.45) | SOT23-5L (2.92 x 2.8 x 1.3) | WLCSP (0.94 X 0.85 X 0.45) | SOT-89-5L (4.5 x 2.45 x 1.5) |
Typical application circuit | 
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