General Description
The APW38HC4XA family are fixed frequency, high performance, current-mode PWM controller with 1.2 A drive current capability. Undervoltage lockout circuitry allows the APW38HC42A and APW38HC44A versions to start up at 14.5V and operate down to 9V, and the APW38HC43A and APW38HC45A versions start at 8.4V with operateion down to 7.6V. All versions operate up to 24V. The ultra low start-up current 25µA (typical), and operating current 2mA (typical) have been designed to improve the converter efficiency. High output driving capability up to 1.2A ensures the fast switching to minimize the switching losses. The APW38HC4XA features a trimmed and temperature compensated oscillator discharge current and bandgap reference. APW38HC4XA is available in both 8-pin plastic DIP and SOP packages.

FEATUREs
• Ultralow start-up current (25µA typical)
• Low operating current (2mA typical)
• Fast output rise/fall times : −15ns rise/10ns fall
• High output drive (1.2A peak current)
• CMOS outputs with rail-to-rail swing
• Current-mode operation up to 1MHz
• Trimmed 5V bandgap reference
• Pin-to-pin compatible with MIC38HC4X
• Trimmed oscillator discharge current
• UVLO with hysteresis
• Low cross-conduction currents

APPLICATIONs
• Current-mode , Off-line , Switched-mode Power Supplies
• Current-mode , DC-to-DC converters
• Various converters ( step-down, step-up, flyback , forward, and synchronous FET)