GM38C45

www.DataSheet4U.com Description GM38C4x is fixed frequency, high performance, and current- mode PWM controllers. Gamma's BiCMOS devices are pin compatible with standard 384x bipolar devices but with several improvements. Undervoltage lockout circuitry allows the '42 and '44 versions to start up at 14.5V and operate down to 9V, and the '43 and '45 versions start at 8.4V with operation down to 7.6V. All versions operate up to 16V. When compared to bipolar 384x devices operating from a 15V supply, start-up current has been reduced to 50µA typical and operating current has been reduced to 4.0 mA typical. Decreased output rise/fall times drive larger MOSFETs, and rail-to-rail output capability increases efficiency, especially at lower supply voltages. GM38C4x also features a trimmed oscillator discharge current and bandgap reference. GM38C4x denotes 8-pin plastic DIP and SOP packages. Features 40ns output rise and 30ns output fall times -40° to +85°C temp. range same as standard UC284x Low-power BiCMOS Process Very low start-up current (50µA typical) Low operating current (4mA typical) CMOS outputs with rail-to-rail swing 500kHz current-mode operation Pin-for-pin compatible with UC3842/ 3843 / 3844/ 3845(A) Trimmed oscillator discharge current UVLO with hysteresis Low cross-conduction currents Application Current-mode, off-line, switched-mode power supplies Current-mode, dc-to-dc converters. Step-down "buck" regulators Step-up "boost" regulators Flyback, isolated regulators For...