The document describes the features and characteristics of UCC3839, including practical secondary side control, use of external N-channel depletion mode FET, onboard precision fixed gain differential current sense amplifier, wide bandwidth current error amplifier, 5V reference, and high current programmable Gm amplifier. The UCC3839 is designed for secondary side average current mode control in isolated power supplies.
The UCC1839, UCC2839, and UCC3839 provide control functions for secondary side average current mode control in isolated power supplies. These devices handle start-up, pulse width modulation, and MOSFET drive independently on the primary side while communicating via an opto-isolator.
| Supply Voltage | 0V to 15V |
|---|---|
| Storage Temperature (UCC3839) | -65°C to +150°C |
| Junction Temperature (UCC3839) | -55°C to +150°C |
| Reference Voltage (UCC3839) | 4.95V to 5.05V |
| Reference Voltage (UCC2839) | 4.9V to 5.1V |
| Reference Voltage (UCC1839) | 4.9V to 5.1V |
| Current Error Amplifier Gain (UCC3839) | 60 dB |
| Voltage Error Amplifier Offset (UCC3839) | 1.475V to 1.525V |
| Current Sense Amplifier Gain (UCC3839) | 8 |
The UCC3839 operates from -65°C to +150°C.
The UCC2839 operates from -40°C to 85°C.
The UCC1839 operates from -55°C to 125°C.
Power is generated by peak rectifying the voltage of the secondary winding using an external N-channel depletion mode FET.