The UC28025N is a fixed-frequency Pulse Width Modulation (PWM) Controller optimized for high-frequency switched-mode power supply applications. The UC28025 offers dual alternating outputs for double-ended and full bridge topologies. The UC2802x include an oscillator, a temperature compensated reference, a wide band width error amplifier, a high-speed current-sense comparator and high-current active-high totem-pole outputs to directly drive external MOSFETs. Protection circuitry includes a current limit comparator with a 1V threshold, a TTL compatible shutdown port and a soft-start pin which will double as a maximum duty cycle clamp. The logic is fully latched to provide jitter free operation and prohibit multiple pulses at an output. An undervoltage lockout section with 800mV of hysteresis assures low start-up current. During undervoltage lockout, the outputs are high impedance.
Peak current mode, average current mode, or voltage mode (with feed-forward) control methods
Wide bandwidth error amplifier
Fully latched logic with double pulse suppression
Pulse-by-pulse current limiting
Programmable maximum duty cycle control
Under-voltage lockout with hysteresis
Trimmed 5.1V Reference with UVLO
50ns Propagation delay to output
±1.5A Peak totem pole outputs
Green product and no Sb/Br
Device has limited built-in ESD protection, leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
