器件名称: UC28025DW
功能描述: ECONOMY HIGH-SPEED PWM CONTROLLER
文件大小: 394.25KB 共18页
简 介:UC28023 UC28025
SLUS557B MARCH 2003 REVISED APRIL 2004
ECONOMY HIGHSPEED PWM CONTROLLER
FEATURES D Peak Current Mode, Average Current Mode, D D D D D D D D D D D
or Voltage Mode (with Feed-Forward) 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 Range 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
DESCRIPTION
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 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 1-V 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 o……
