Document
Fremont Micro Devices
FT833xxx
High Precision PSR Constant Current LED Driver
FMD Confidential
FEATURES
Built-in 650V power MOSFET PSR constant current control without
secondary sense and feedback circuit No auxiliary winding for sensing and supplying Ultra low operating current for high efficiency Universal input voltage ±3% LED current accuracy Choice for maximum duty cycle and OVP
voltage Precision OVP voltage for best LED open
circuit protection LED short circuit protection CS resistor short circuit protection VCC under-voltage protection Over temperature compensation Available in SOP8 and DIP8 packages
APPLICATIONS
Isolated solid state lighting GU10/E27 LED bulb, spot light Other LED lighting
DESCRIPTION
FT833xxx is a high precision primary-side feedback and regulation constant current driver for LED lighting applications. It is designed to work in inductor current discontinuous conduction mode (DCM) and is especially suitable for flyback converter under universal input. Under universal input voltage from 90V to 264V, the system output power for FT833Sxx, FT833Axx, FT833Bxx (SOP8) and FT833BD (DIP8) is recommended to be no more than 3W, 6W, 9W, and 12W, respectively.
The FT833xx integrates a 650V power MOSFET and eliminates secondary sense and feedback circuit. The loop compensation components are also removed while maintaining stability over all operating conditions. It uses a source drive architecture and special demagnetization sensing technology with very low operating current, the auxiliary winding for sensing the output and supplying the chip is therefore eliminated, resulting in low component counts and small system size.
With its highly accurate current sense method, the FT833xxx realizes ±3% accuracy of LED current along with excellent line and load regulation.
The multi-protection function of FT833xxx can greatly enhance the system reliability and safety. The FT833xxx features LED open/short circuit protection, CS resistor short circuit protection, over temperature compensation and VCC UVLO protection. The industry leading OVP voltage accuracy ensures the best LED open circuit protection.
© 2013 Fremont Micro Devices Inc.
Confidential Rev1.1
DS833xxx-A-page1
Fremont Micro Devices
TYPICAL APPLICATION CIRCUIT
FT833xxx
AC INPUT
+
+ Vo +
FMD Confidential
+
VCC TP
DRAIN DRAIN
FT833xxx
NC CS NC
GND
Vo -
Figure 1. Typical Application Circuit
ABSOLUTE MAXIMUM RATINGS
VCC to GND………………………………………………………………………………………………-0.3V to 20V CS Pin Inputs and Outputs……………………………………………………………………….……….. -0.3V to 6V DRAIN Pin Inputs and Outputs………………………………………………….………………………-0.3V to 650V TP Pin Inputs and Outputs…………………………………………………………..……………………-0.3V to 20V Operating Temperature Range………………………………………………………………………-40℃ to +105℃ Junction Temperature…………………………………………………………………………...........-40℃ to +150℃ Storage Temperature Range ……………………………………………………...…………………-60℃ to +150℃ ESD Protection HBM………………………………………………………………………………….