MC33025

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 specifically designed 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 Start-Up Current 500 mA 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 Simplified

.

Pb-Free Packages are Available