The UC28023 and UC28025 are fixed-frequency PWM controllers optimized for high-frequency switched-mode power-supply applications. The UC28023 is a single output PWM for single-ended topologies while the UC28025 offers dual alternating outputs for double-ended and full bridge topologies.
●Targeted for cost-effective solutions with minimal external components. UC2802x devices include an oscillator, a temperature compensated reference, a wide bandwidth 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 1-V threshold, a TTL compatible shutdown port, and a soft-start pin which doubles 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 800 mV of hysteresis assures low start-up current. During undervoltage lockout, the outputs are high impedance. Propagation delays through the comparators and logic circuitry have been minimized while maximizing bandwidth and slew rate of the error amplifier.
●Devices are available in the industrial temperature range of –40°C to 105°C. Package offerings are 16-pin SOIC (DW), or 16-pin PDIP (N) packages.
● Peak Current Mode, Average Current Mode, or Voltage Mode (With FeedForward) Control Methods
● Practical Operation Up to 1 MHz
● 50-ns Propagation Delay to Output
● ±1.5-A Peak Totem Pole Outputs
● 9-V to 30-V Nominal Operational Voltage
● Wide Bandwidth Error Amplifier
● Fully Latched Logic With Double Pulse Suppression
● Pulse-by-Pulse Current Limiting
● Programmable Maximum Duty Cycle Control
● Undervoltage Lockout With Hysteresis
● Trimmed 5.1-V Reference With UVLO
● Same Functionality as UC3823 and UC3825
