illustrate

The UC28023 and UC28025 are controllers optimized for fixed frequency PWM high frequency switch-mode power supply applications. The UC28023 is a single-ended topology, while the UC28025 offers dual alternating double-ended outputs and full-bridge topologies with single output PWM.

Designed as a cost-effective solution with minimal external components, the UC2802x includes an oscillator, temperature compensated reference, wide band width error amplifier, a high speed current sense comparator, and a high current high effective totem pole output to drive an external MOSFET directly.

The protection circuitry includes a threshold current limit comparator with 1 - V, a TTL-compatible shutdown port, and a soft-start pin that doubles the maximum duty cycle clamp.

characteristic

• Peak current mode, average current mode or voltage mode
  (with feed-forward) control methods
• Practical operation up to 1 MHz
• 50 - ns propagation delay to output
• ± 1.5 peak totem pole output
• 9 V to 30 V rated operating voltage range
• Wideband error amplifier
• Full lock-in logic double-pulse suppression
• The pulse is limited by the pulse current
• Programmable maximum duty cycle control
• Undervoltage lockout and hysteresis
• Edge 5.1-V with UVLO reference
• Same features as UC3823 with UC3825
• apply
  • Offline and DC/DC power supplies
  • The converter adopts voltage mode, peak current mode,
    or average current mode control method
  • Single-ended or dual-switch topology design