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The UC3845 is a fixed frequency current-mode PWM controller. It is specially designed for Off-Line and DC to DC converter applications with minimum external components. This integrated circuit feature a trimmed oscillator for precise duty cycle control, a temperature compensated reference, a high gain error amplifier, a current sensing comparator, and a high current totem pole output for driving a Power MOSFET. The UC3845 has UVLO thresholds of 8.5V (on) and 7.9V (off). The UC3845 can operate within a 50% duty cycle.
UC3845 Pinout
UC3845 Pin Configuration
| Pin No | Pin Name | Description |
|---|---|---|
| 1 | COMP: | Compensation Pin |
| 2 | VFB | FeedBack Voltage Pin |
| 3 | CURRENT SENSE | Current Sense Pin |
| 4 | RT/CT | Resistor/Capacitor Timing Pin |
| 5 | GND | Ground Pin |
| 6 | OUTPUT | Output Pin |
| 7 | VCC | Supply Voltage |
| 8 | Vref | Voltage Reference Pin |
UC3845 Features
- Low Start up Current
- Maximum Duty Clamp
- UVLO With Hysteresis
- Operating Frequency up to 500KHz
- Temperature compensated reference
- High gain amplifier
- Current sensing comparator
- High current totem pole output
Application
- Off-Line
- DC to DC converter
You can download this datasheet for UC3845 Current Mode PWM Controller – Datasheet from the link given below:
