The UCC3807 family of high speed, low power integrated circuits contains all of the control and drive circuitry required for off-line and DC-to-DC fixed frequency current mode switching power supplies with minimal external parts count. These devices are similar to the UCC3800 family, but with the added fea- ture of a user programmable maximum duty cycle. Oscillator frequency and maximum duty cycle are programmed with two resistors and a capacitor. The UCC3807 family also features internal full cycle soft start and internal leading edge blanking of the current sense input. The UCC3807 family offers a variety of package options, temperature range options, and choice of critical voltage levels. The family has UVLO thresholds and hysteresis levels for off-line and battery powered systems. Thresholds are shown in the table below.
The UCC3807 family of high‑speed, low‑power PWM controller ICs provides all control and drive circuitry required for off‑line and DC‑to‑DC fixed‑frequency current‑mode switching power supplies. Key features include a user‑programmable maximum duty cycle, internal full‑cycle soft start, leading‑edge blanking of the current‑sense input, and built‑in UVLO thresholds.
The devices are offered in DIL‑8, SOIC‑8, and TSSOP‑8 packages and support a wide range of operating conditions, with supply voltages up to 13.5 V, output currents up to ±1 A, and oscillator frequencies from 175 kHz to 228 kHz. Typical applications include off‑line converters, flyback regulators, and other power‑management designs.
| Supply Voltage (IDD) | 13.5 V |
|---|---|
| Supply Current | 30 mA |
| Output Current | ± 1 A |
| Oscillator Frequency | 175‑228 kHz |
| Maximum Duty Cycle | 75‑81 % |
| UVLO Start Threshold | 6.6‑7.8 V |
The PWM controller can be programmed for a maximum duty cycle between 75 % and 81 % typical.
The devices are available in DIL‑8, SOIC‑8, and TSSOP‑8 packages.
Typical startup current is 0.1 mA to 0.2 mA depending on the variant.
UCC1807 operates from –55 °C to +125 °C, UCC2807 from –40 °C to +85 °C, and UCC3807 from 0 °C to +70 °C.