Low Power LED Driver DW3505A for GENERAL DESCRIPTION:
The DW3505A is an instant On/Off LED driver for low power LED applications. At DW3505A 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.
DW3505A easily provides users a consistent current source. User may adjust the output current from up to 300mA 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.
DW3505A also guarantees that LEDs can be cascaded to maximum 40V at the output port.
DW3505A 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
DW3505A Features:
● Constant output current invariant to supply and load voltage change
● 5V to 40V supply voltage
● Up to 300mA adjustable regulated output current
● Built-in thermal derating circuit
● Available PWM dimming control
● Output current adjusted through an external resistor
● SOT89-5L(4.5 x 2.45 x 1.5(mm) Package
DW3505A Pin placement and IC dimension:
DW3505A Pin Description
Pin
| PIN Name | Description |
1
| RS
| Output current set input. Connect a resistor from RS to GND to set the LED bias current.
|
| 2 | GND
| Ground.
|
| 3 | 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. |
| 4 | OUT
| Output pin. Sink current is decided by the current on RSET connected to RS. |
| 5 | VDD
| Supply voltage input. |
DW3505A Block Diagram
DW3505A Typical Operating Characteristics
DW3505A PWM Dimming Typical Application
DW3505 vs. BCR320U/BCR420U Contrast test
| DW3505 | BCR320U
| BCR420U
| Remark |
Vender
| DONGWOON | infineon | infineon | -
|
Operating voltage | 5V~40V | ~25V | ~40V | -
|
PKG Size | 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 | O
(PWM input up to 20KHz) | O
(PWM input up to 10KHz) | O
(PWM input up to 10KHz) | -
|
Output Current | Up to 300mA
Adjustable | Up to 250mA
Adjustable | Up to 150mA
Adjustable | Output current is required
set by considering the actual
PKG' surface temperature. |
Temperature
Protection | O | X | X | LED module is requiredhigh
temperature protection |
Dropout Voltage | 0.1V@60mA | 1.4V (Iout>18mA) | 1.4V (Iout>18mA) | DW3505 helps to install
many LED module on SMPS |
Variation by Temp. | Under ±2%
(at 60mA) | - | ±10%
(at 52mA) | Temperature -40℃~145℃ |
Iout Variation
At VEN Voltage | Under ±0.5%
(VEN 5~40V) | -
| 40mA~52mA
(VEN 5V~25V) | BCR320U need to select
VEN voltage |
Accuracy | ±5% (at 60mA) | - | ±10% (at 10mA) | -
|
Output current characteristics by Temperature change
vCondition: VIN 12V, VOUT3V, IOUT 60mA/150mA, Temp -40℃~150℃
ØDW3505 Output Current Accuracy
àOutput Current 60mA Setting : -1.3% ~ 0.68%
àOutput Current 150mA Setting : -1.52% ~ 1.31%
vØAs DW3505 operate the thermal derating protection at 140°C~150 °C,output current values reduce to ¼.
ØBCR320U have no thermal protection circuits
Output current characteristics by EN pin voltage change
vDW3505 Condition : VIN 30V, VEN0V~30V, VOUT 2V, RSETParameter, Ta 25℃
vBCR320U Condition : IOUT=f(VEN),VOUT 2V, REXT3ohm, Refer to datasheet 16page
ØIn the case of DW3505, when a voltage higher than 2V isapplied to the EN pin, it drives normally.
èOutput current accuracy : ±0.01%
ØIn the case of BCR320U, output current regulation is notgood according to the voltage applied to EN pin.
DONGWOON Linear constant current solution recommend：
| 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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