Description

GM384XA series is high performance with fixed frequency current mode PWM controllers. They are specially designed for off-Line and DC-to-DC converter applications with minimum external components. These devices feature a trimmed oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier, current sensing comparator, and high current totem pole output which is suitable for driving MOSFETs.

The under voltage lock-out (U.V.L.O.) is designed to operated with 0.17mA typ. start-up current, allowing an efficient bootstrap supply voltage design. The U.V.L.O. thresholds for the AMC3842A/44A are 16V (on) and 10V (off) which are ideal for off-line applications. The corresponding typical threshold for the GM3843A/45A is 8.4V (on) and 7.6V (off). The GM3842A/43A can operated within 100 duty cycle and the GM3844A/45A can operated within 50 duty cycle.

Features

♦ Low Start-Up and Operating Current

♦ Automatic Feed Forward Compensation

♦ Current Mode Operating Frequency up to 500KHz

♦ Trimmed Oscillator Discharge Current for Precise Duty Cycle Control

♦ Latching PWM for Cycle-By-Cycle Current Limiting

♦ Under Voltage Lockout with Hysteresis

♦ High Current totem Pole Output Stage

Application

Off-line flyback or forward converters

DC-to DC buck boost converter

Monitor Power Supply