STMicroelectronics

Description

UC2844A, UC2845A ,. UC3842A, UC3843A,. UC3844A, UC3845A. PDIP (8). 6.35 mm 9.81 mm. SOIC (8). 3.91 mm 4.90 mm. SOIC (14). 3.91 mm 8.65 mm. SOIC (16). 7.50 mm 10.30 mm. (1) For all available packages, see the orderable addendum at the end of the data sheet. Device Comparison Table. DEVICE. DESCRIPTION. The UC384xB family of control ICs provides the nec- essary features to implement off-line or DC to DC fixed frequency current mode control schemes with a minimal external parts count. Internally imple- mented circuits include a trimmed oscillator for pre- cise DUTY CYCLE CONTROL under voltage lock-. The UTC UC2844/2845 are high performance fixed frequency current mode controllers that specifically designed for Off-Line and. DC to DC converter applications with minimal external parts count. The differences between UC2844 and UC2845 are the maximum duty cycle ranges and under-voltage lockout thresholds. ABSTRACT. National Semiconductor marks devices sold in order to provide device identification and manufacturing traceablility information. The method of presenting the information marked on the device is dependent on the size of the device package and the area available for marking, as well as the nature and UC2845 : Linear Current Switching Regulator Controller. For complete documentation, see the data sheet. The UC3844, UC3845 series are high performance fixed frequency current mode controllers. They are specifically designed for Off-. Line and dc-to-dc converter applications offering the designer a cost effective