Part Number: SD4841, SD4840 Thru SD4844
Function: Current Mode PWM( Pulse Width Modulation ) Controller
Package: DIP 8 Pin
Manufacturer: Silan Microelectronics
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Description
This is CURRENT MODE PWM CONTROLLER WITH BUILT-IN HIGH VOLTAGE MOSFET.
The SD4841 is a current mode PWM controller with low standby power and low start current for power switch. In standby mode, the circuit enters burst mode to reduce the standby power dissipation. The switch frequency is 67KHz with ±2.5 KHz jitter frequency for low EMI. The stress on transformer during power on is reduced by the builtin 15ms soft start circuit to avoid the saturation of transformer.
Pinout
1. SGND : GND of control circuit
2. PGND : GND of MOSFET
3. VCC : Power supply
4. FB : Feedback input
5. NC : No connection
6. Drain : Drain end of MOSFET
7. Drain : Drain end of MOSFET
8. Drain : Drain end of MOSFET
Features
A current mode PWM (Pulse Width Modulation) controller is an electronic device used in power electronic circuits to regulate the output voltage of a power supply. It compares a reference signal to a feedback signal from the output of the power supply and adjusts the duty cycle of the PWM signal sent to a power switch to maintain the desired output voltage.
The main advantage of current mode control over voltage mode control is that it can provide a faster response to changes in the load current, making it more suitable for applications with rapidly changing loads. It also offers better noise immunity and improved stability over a wider range of operating conditions.
1. Lower start-up current (Typ.6μA)
2. Frequency jitter for low EMI
3. Overcurrent protection
4. Overvoltage protection
5. Undervoltage lockout
6. Built-in temperature protection
7. Built-in high voltage MOSFET
Applications:
1. Switch power
Block Diagram
Other data sheets are available within the file: SD4840, SD4840P67K65, SD4841, SD4841P67K65, SD4842
SD4841 Datasheet PDF Download
