UC3844A

UC284XA UC384XA HIGH PERFORMANCE CURRENT MODE PWM CONTROLLER NOT FOR NEW DESIGN 1 FEATURES Figure 1. Package ■ TRIMMED OSCILLATOR DISCHARGE CURRENT ■ CURRENT MODE OPERATION TO 500kHz AUTOMATIC FEED FORWARD COMPENSATION DIP-8 SO-8 ■ LATCHING PWM FOR CYCLE-BY-CYCLE CURRENT LIMITING Table 1. Order Codes ■ INTERNALLY TRIMMED REFERENCE WITH Part Number Package UNDERVOLTAGE LOCKOUT ■ HIGH CURRENT TOTEM POLE OUTPUT t(s)UNDERVOLTAGE LOCKOUT WITH HYSTERESIS c■ LOW START-UP CURRENT (< 0.5mA) uDOUBLE PULSE SUPPRESSION rod2 DESCRIPTION PThe UC384xA family of control ICs provides the necessary features to implement off-line or DC to teDC fixed frequency current mode control schemes lewith a minimal external parts count. Internally imoplemented circuits include a trimmed oscillator for sprecise DUTY CYCLE CONTROL under voltage blockout featuring start-up current less than 0.5mA, Oa precision reference trimmed for accuracy at the -error amp input, logic to insure latched operation, )a PWM comparator which also provides current t(slimit control, and a totem pole output stage decsigned to source or sink high peak current. The uoutput stage, suitable for driving N-Channel MOSdFETs, is low in the off-state. UC2842AD1; UC3842AD1; UC2843AD1; UC3843AD1; UC2844AD1; UC3844AD1; UC2845AD1; UC3845AD1 UC2842AN; UC3842AN; UC2843AN; UC3843AN; UC2844AN; UC3844AN; UC2845AN; UC3845AN SO-8 DIP-8 Differences between members of this family are the under-voltage lockout thresholds and maximum ...