| Topology | Flyback, Forward |
| Duty cycle (Max) (%) | 90 |
| Vin (Max) (V) | 14.5 |
| UVLO thresholds on/off (V) | 13.0/8.0 |
| Features | Adjustable Switching Frequency, Current Limiting, HV Start-up, Input Line Monitor, Multi-topology, Programmable Max Duty Cycle, Programmable Slope Compensation, Soft Start |
| Operating temperature range (C) | -40 to 105 |
| Switching frequency (Max) (kHz) | 2000 |
| Rating | Catalog |
| Gate drive (Typ) (A) | 0.01 |
- 2-MHz High-Frequency Oscillator With 1-MHz Operation Per Channel
- Matched Internal Slope Compensation Circuits
- Programmable Maximum Duty Cycle Clamp 60% to 90% Per Channel
- Peak Current Mode Control With Cycle-by-Cycle Current Limit
- Current Sense Discharge Transistor for Improved Noise Immunity
- Accurate Line Undervoltage and Overvoltage Sense With Programmable Hysteresis
- Opto-Coupler Interface
- 110-V Internal Start-Up JFET (UCC28221)
- Operates From 12-V Supply (UCC28220)
- Programmable Soft Start
The UCC28220 and UCC28221 are a family of BiCMOS interleaved dual channel PWM controllers. Peak current mode control is used to ensure current sharing between the two channels. A precise maximum duty cycle clamp can be set to any value between 60% and 90% duty cycle per channel.
The UCC28220 has an UVLO turnon threshold of
10 V for use in 12-V supplies while UCC28221 has a turnon threshold of 13 V for systems needing wider UVLO hysteresis. Both have 8-V turnoff thresholds.
Additional features include a programmable internal slope compensation with a special circuit which is used to ensure exactly the same slope is added to each channel and a high-voltage 110-V internal JFET for easier start-up for the wider hysteresis UCC28221 version.
The UCC28220 is available in both 16-pin SOIC and low-profile TSSOP packages. The UCC28221 also comes in 16-pin SOIC package and a slightly larger 20-pin TSSOP package to allow for high-voltage pin spacing to meet UL1950 creepage clearance safety requirements.
