Internal Block Diagram
BP3102
High Precision PSR Constant Current LED Driver
Figure 3. BP3102 Internal Block Diagram
Function Description
The BP3102 is a high performance power switch
specially designed for LED lighting, it uses the
patent constant current control technology of BPS.
The BP3102 integrates a 600V power MOSFET. The
accurate LED current can be realized without
opto-coupler and TL431 feedback circuit while
minimizing the external component count, lowering
the total bill of material cost.
Start Up
The start-up current in BP3102 is designed to as low
as 25uA. The VCC capacitor will be charged through
the start-up resistor when the system is powered on,
once the voltage on VCC reaches the start-up
threshold, the BP3102 will start to operate, and then
the VCC is supplied by the auxiliary winding.
Constant Current Control
Cycle-by-Cycle current sense is offered in BP3102,
the CS is connected to the current sense comparator,
and the voltage on CS will be compared with the
internal 500mV reference voltage, the MOSFET will
be switched off when the voltage on CS reaches the
threshold. The output of the comparator also includes
a 500nS leading edge blanking time
The primary peak current is given by:
I P_PK
=
500
(mA)
RCS
The current in LED can be calculated by the
equation:
BP3102_DS_Rev.1.0
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