WS3130 Datasheet, PDF (6/8 Pages) List of Unclassifed Manufacturers – High Performance LED Driver

WS3130 Product Description
unit is employed between the CS Pin and the current
comparator input.During the blanking time,the path,CS Pin to
the current comparator input,is blocked.Figure shows the
leading edge blanking.
typical is 1.0V, the power MOSFET is turned off for the
remainder of that cycle.
Leading-Edge Blanking For FB Pin
As shown in Fig, when the power MOSFET is turned off,
a damping voltage spike will occur at FB pin due to parasitic
capacitance of power MOSFET and leak inductor of
transformer. An internal leading edge blanking (LEB) was
introduced to filter this noise.
Output over Voltage Protection
Output over voltage protection can prevent the
components from damage in the over voltage condition.The
positive plateau of auxiliary winding voltage is proportional to
the output voltage. The OVP uses the auxiliary winding
voltage instead of directly monitoring the output voltage.
Once the FB pin voltage is higher than 3.6V, the OVP signal
will be triggered and latched, the gate driver will be turned off
and the IC work at quiescent mode, the VDD voltage dropped
below the UVLO which will make the IC shut down and the
system restarts again.The output OVP setting point can be
calculated as:
V_{OUT _ OVP}
 3.6
N_s
N _AUX

R_FBH  R_FBL
R_FBL
V_{OUT_OVP ……Output over voltge protection value}
N_{AUX ……the auxiliary winding turns}
N_{s ……the secondary winding turns}
Current Limit
The current limit circuit senses the current of inductor by
CS pin. When this current exceeds the internal threshold,
Output Short Circuit Protection
When the output short circuit happens, the positive
plateau of auxiliary winding voltage is also near zero. The IC
will shut down and restart again once FB voltage falls
below 1.0V and lasts for about 20mS.
Thermal Shut Down
The thermal shutdown circuitry senses the die
temperature.The threshold is set at 150℃ typical with a 25℃
hysteresis.When the die temperature rises above this
threshold (150 ℃ ),the 840X turn off the power MOSFET by
DRV and remains turning off until the die temperature falls by
25℃,at which point it is re-enabled.
VDD over Voltage Protection
WS3130 provides an over voltage protection circuit for
VDD pin. The GATE output will shut down once the VDD
voltage exceeds 25V (typical value), the IC would restart until
VDD drops to 9.0V.
Fault protection
There is several default protections were integrated in
the WS3130 to prevent the IC from being damaged which
including FB pin open or short, CS pin open.
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
www.winsemi.com Tel : [phone] Fax : [phone]
WINSEMI MICROELECTRONICS
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