SD4844 Datasheet – Current Mode PWM Controller
SD4844 overview
The SD4844 is a Current Mode PWM Controller made by Silan Microelectronics, supplied in a DIP 8 Pin Type package. The absolute maximum ratings table on this page lists the 5 limits from the manufacturer's datasheet that must not be exceeded. This page brings together the SD4844 pinout and maximum ratings, with the full datasheet PDF to preview below or download.
SD4840/4841/4842/4843/4844 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 built- in 15ms soft start circuit to avoid the saturation of transformer. SD4840/4841/4842/4843/4844 includes under voltage lock-out, over voltage protection, leading edge blanking, over current protection and the temperature protection. The circuit will restart automatically until the system is normal after the protection is active.
Datasheet
SD4844 features
- Lower start-up current (Typ.6mA)
- Frequency jitter for low EMI
- Overcurrent protection
- Overvoltage protection
- Undervoltage lockout
- Built-in temperature protection
- Built-in high voltage MOSFET
- Auto restart mode
- Built-in soft start
- Burst mode operation
- Cycle by cycle current limit
SD4844 pinout
| Pin | Name | Description |
|---|---|---|
| 1 | SGND | Ground for control part. |
| 2 | PGND | MOSFET Ground. |
| 3 | VCC | Power supply pin. |
| 4 | FB | Feedback input pin. |
| 5 | NC | Not connected. |
| 6,7,8 | Drain | Drain pins. |
Absolute maximum ratings
| Parameter | Value | Unit |
|---|---|---|
| Drain-Gate Voltage (RGS=1MΩ) V | 650 | V |
| Gate-Source (GND) Voltage | ±30 | V |
| Power Supply Voltage | 21 | V |
| Analog Input Voltage | -0.3~ V | V |
| Darting | 0.017 | W/°C |
SD4844 applications
- Switch power
- Power Amplification
- Audio Systems
- Consumer Electronics
- Industrial Control
- Automotive Audio
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