|
WINSEMI |
WS3215
40V/1.5A Step-down High Brightness LED Driver
Features
■ Simple low parts count
■ Wide input voltage range:8V to 40V
■ Up to 1.5A output current
■ Output current limit protection
■ Over temperature protection
■ Single pin on/off and brightness control using DC
Voltage or PWM
■ Typical 5% output current accuracy
■ Inherent open-circuit LED protection
■ High efficiency (up to 97% )
■ Adjustable LED constant current
Applications
■ MR16 LEDs
■ Automotive lighting
■ Low Voltage industrial lighting
■ illuminated signs
Typical Application Circuit
Description
The WS3215 is a continuous conduction mode inductive
step-down converter.designed for driving single or
multiple series LED efficiently from a voltage source
higher than the total LED chain voltage. The device
operates from an input supply between 8V and 30V and
provides an external adjustable output current of up to
1.5A.Depending upon supply voltage and external
components, the WS3215 can provide more than 10 watts
of output power. The WS3215 includes the power switch
and a high-side output current sensing circuit .which uses
an external resistor to set the nominal average output
current, and a dedicated DIM input accepts either a DC
voltage or a wide range of pulsed dimming. Applying a
voltage of 0.3V or lower to the DIM pin turns the output off
and switches the device into a low current standby state.
WS3215 using SOT89-5 package .
Rev.1.0 July.2011
Copyright@Winsemi Microelectronics Co., Ltd., All right reserved.
Pin Definition and Device Marking
WS3215
Pin Function Description
Pin Name Pin No. Pin Type
SW 1
Output
GND
2
Power
3
DIM
Floating
CSN
4
5
VIN
6
Exposed PAD
Current
Monitoring
Frequency
Setting
Floating
Function Description
Drain terminal of internal Power MOSFET.
Signal and Power GND.
Used for enabling Switch and Dimming with either a DC voltage or
PWM input signal .
Used for high-side output current sensing with an external sensing
resistance between CSN and VIN.
Power supply input. Bypass with capacitor as close to the device as
possible .
Connected to GND for thermal considerations and pasted on PCB for
reducing thermal resistance.
Block Diagram
Steady, keep you advance
2/9
|