The UCC28C5x-Q1 series of control integrated circuits provide the features necessary to implement AC-DC or DC‑to-DC fixed-frequency current-mode control schemes with a minimum number of external components. Protection circuitry includes undervoltage lockout (UVLO) and current limiting. Internally implemented circuits include a start-up current of less than 75 µA, a precision reference trimmed for accuracy at the error amplifier input, logic to ensure latched operation, a pulse-width modulation (PWM) comparator that also provides current-limit control, and an output stage designed to source or sink high-peak current. The output stage, suitable for driving N-channel MOSFETs, is low when it is in the OFF state. The oscillator contains a trimmed discharge current that enables accurate programming of the maximum duty cycle and dead time limit, making this device suitable for high-speed applications.

Major differences between members of this series are the UVLO thresholds, acceptable ambient temperature range, and maximum duty cycle and frequency. Typical UVLO thresholds of 14.5 V (ON) and 9 V (OFF) on the UCC28C52-Q1 and UCC28C54-Q1 devices make them ideally suited to off-line AC-DC applications. The corresponding typical thresholds for the UCC28C53-Q1 and UCC28C55-Q1 devices are 8.4-V (ON) and 7.6-V (OFF), making them ideal for use with regulated input voltages used in DC-DC applications. The UCC28C50-Q1 and UCC28C51-Q1 feature a start-up threshold of 7 V and a turnoff threshold of 6.6 V (OFF), which makes them suitable for battery- powered applications. The UCC28C56H/L-Q1, UCC28C57H/L-Q1, UCC28C58-Q1 and UCC28C59-Q1 operate with higher start-up thresholds for them suitably to work with SiC MOSFETs which often being used in high-voltage and high-power traction inverter applications. The UCC28C56H-Q1 and UCC28C57H-Q1 are with a start-up threshold 18.8-V (ON) and 15.5-V (OFF). The UCC28C56L-Q1 and UCC28C57L-Q1 are with a start-up threshold 18.8-V (ON) and 14.5-V (OFF). The UCC28C58-Q1 and UCC28C59-Q1 are with a start-up threshold 16-V (ON) and 12.5-V (OFF). The UCC28C50-Q1, UCC28C52-Q1, UCC28C53-Q1, UCC28C56H/L-Q1 and UCC28C58-Q1 devices operate to duty cycles approaching 100%. The UCC28C51-Q1, UCC28C54-Q1, UCC28C55-Q1, UCC28C57H/L-Q1 and UCC28C59-Q1 obtain a duty cycle from 0% to 50% by the addition of an internal toggle flip-flop, which blanks the output off every other clock cycle. The UCC28C5x series is specified for operation from –40°C to 125°C. The switching frequency (fSW) of the UCC28C50-Q1, UCC28C52-Q1, UCC28C53-Q1, UCC28C56H/L-Q1 and UCC28C58-Q1 gate drive is equal to fOSC; the switching frequency of the UCC28C51-Q1, UCC28C54-Q1, UCC28C55-Q1, UCC28C57H/L-Q1 and UCC28C59-Q1 is equal to half of the f_OSC.

The UCC28C5x-Q1 series are an enhanced replacement with pin-to-pin compatibility to the BiCMOS UCC28C4x- Q1 families. The new series offers improved performance when compared to older bipolar devices and other competitive BiCMOS devices with similar functionality. These improvements generally consist of tighter specification limits that are a subset of the older product ratings, maintaining drop-in capability. In new designs, these improvements can reduce the component count or enhance circuit performance when compared to the previously available devices.