Part Number: SD6834
Function: CURRENT MODE PWM+PFM CONTROLLER WITH BUILT-IN HIGH VOLTAGE MOSFET
Package: DIP 8 Pin Type
Manufacturer: Silan Microelectronics
Image and Pinouts:
The SD6834 is built for high-voltage MOSFET switching power supply external sense resistor. The current mode PWM + PFM controller family. The circuit is low standby power consumption, low starting current. SD6834 is current mode PWM+PFM controller with built-in high-voltage MOSFET used for SMPS. It features low standby power and low start current. In standby mode, the circuit enters burst mode to reduce the standby power dissipation. The switch frequency is 25~67KHz decided by the load with jitter frequency
Built-in peak current compensation circuit makes the limit peak current stable even with different input AC voltage. Maximum peak current compensation during power-on reduces pressure on transformer to avoid saturation, the peak current compensation will decrease for balance after power-on. Limit output current can be adjusted through the resistor connected to CS. It integrates various protections such as undervoltage lockout, overvoltage protection, overload protection, leading edge blanking, primary winding overcurrent protection and thermal shutdown. The circuit will restart until normal if protection occurs.
Block Diagram :
The SD6834 is used for off-line switching power supply integrated circuits. Gate driver circuit includes high-voltage power circuit MOSFET, optimized and current mode Type PWM + PFM controller. The controller includes a frequency oscillator and various protection functions. Frequency jitter oscillator circuit can be reduced EMI. Maximum peak current compensation circuit reduces the stress starts transformer. CS terminal resistance can be adjusted by the limit peak current. In the light load When the circuit hiccup mode can effectively lower standby power consumption. Protection features include: undervoltage lockout, overvoltage protection, overload protection Care, primary coil overcurrent protection and thermal protection. The leading edge blanking function of the circuit, the MOSFET has opened to ensure the shortest possible time, eliminating the The interference caused by erroneous MOSFET off.
1. Various switching frequency following load for the high efficiency
2. EMI Frequency jitter for low EMI
3. Overvoltage, primary winding overcurrent, overload and over temperature protections
4. External peak current sense resistor
5. Undervoltage lockout
6. Built-in high voltage MOSFET