MC34025P

高速双端PWM控制器 High Speed Double-Ended PWM Controller

The MC34025 series are high speed, fixed frequency, double−ended pulse width modulator controllers optimized for high frequency operation. They are specificallydesigned for Off−Line and DC−to−DC converter applications offering the designer a cost effective solution with minimal external components. These integrated circuits feature an oscillator, a temperature compensated reference, a wide bandwidth error amplifier, a high speed current sensing comparator, steering flip−flop, and dual high current totem pole outputs ideally suited for driving power MOSFETs. Also included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cycle−by−cycle current limiting, and a latch for single pulse metering. The flexibility of this series allows it to be easily configured for either current mode or voltage mode control.

Features

•50 ns Propagation Delay to Outputs

•Dual High Current Totem Pole Outputs

•Wide Bandwidth Error Amplifier

•Fully−Latched Logic with Double Pulse Suppression

•Latching PWM for Cycle−By−Cycle Current Limiting

•Soft−Start Control with Latched Overcurrent Reset

•Input Undervoltage Lockout with Hysteresis

•Low Startup Current 500 A Typ

•Internally Trimmed Reference with Undervoltage Lockout

•45% Maximum Duty Cycle Externally Adjustable

•Precision Trimmed Oscillator

•Voltage or Current Mode Operation to 1.0 MHz

•Functionally Similar to the UC3825

•Pb−Free Packages are Available

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