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晶丰明源半导体
BP2836D
Non-isolated Buck Offline LED Driver
Description
The BP2836D is a high precision buck constant
current LED driver. The device operates in critical
conduction mode and is suitable for 85Vac~265Vac
universal input offline LED lighting.
The BP2836D integrates a 500V power MOSFET.
With patent pending MOSFET driving technique, the
operating current of the IC is very low. So it doesn’t
need the auxiliary winding for supplying the chip. It
can achieve excellent constant current performance
with very few external components, so the system
cost and size are minimized.
The BP2836D utilizes patent pending current control
method. It can achieve precise output current and
excellent line regulation. The driver operates in
critical conduction mode, the output current does not
change with the inductance and LED output voltage.
The BP2836D offers rich protection functions to
improve the system reliability, including LED open
circuit protection, LED short circuit protection, VCC
under voltage protection, CS resistor short circuit
protection and thermal regulation function.
Features
Critical Conduction Mode Operation
Internal 500V Power MOSFET
No Auxiliary Winding
Ultra Low Operating Current
±5% LED Output Current Accuracy
LED Open Protection
LED Short Protection
Current Sensing Resistor Short Protection
VCC Under Voltage Protection
Thermal Regulation Function
Available in DIP-8 Package
Applications
LED Tube
LED Ceiling Light
LED Bulb
Other LED Lighting
Typical Application
AC BP2836D
4 VCC DRAIN 5
2 ROVP DRAIN 6
3 NC
CS 7
1 GND
CS 8
BP2836D_EN _DS_Rev.1.0
Figure 1. Typical application circuit for BP2836D
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晶丰明源半导体
Internal Block Diagram
VCC
9.0V 14V
17V
BP2836D
Non-isolated Buck Offline LED Driver
DRAIN
VCC
HV
MOSFET
OTP
UVLO
RESET
OCP
OVP
ROVP
GND
CC &
Logic Control
LED
+
Current
Sense
-
400mV
CS
Figure 3. BP2836D Internal Block Diagram
Application Information
The BP2836D is a high performance non-isolated
Buck converter specially designed for LED lighting.
The device integrates a 500V power MOSFET. With
very few external components, the converter
achieves excellent constant current control. And it
does not need auxiliary winding for powering the IC
or voltage sensing, hence the system size and cost is
greatly reduced.
Start Up
After system powered up, the VCC pin capacitor is
charged up by the start up resistor. When the VCC
pin voltage reaches the turn on threshold, the internal
circuits start operating. The BP2836D integrates a
17V zener diode to clamp the VCC voltage. Due to
the ultra-low operating current, the auxiliary winding
is not needed to supply the IC.
Constant Current Control
Cycle by Cycle current sense is adopted in BP2836D,
the CS pin is connected to the current sense
comparator, and the voltage on CS pin is compared
with the internal 400mV reference voltage. The
MOSFET will be switched off when the voltage on
CS pin reaches the threshold. The CS comparator
includes a 350ns leading edge blanking time.
The peak inductor current is given by:
I PK
400
R CS
(mA)
Where, RCS is the current sense resistor value.
The current in LED can be calculated by the
equation:
BP2836D_EN _DS_Rev.1.0
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