UC2842B中文资料HIGH-PERFORMANCE CURRENT-MODE PWM CONTROLLERS数据手册UTC规格书

描述 Description

The  UTC  UC2842B  provides  off-line  or  DC-DCfixed-frequency current-mode control design with minimumexternal components. Internally-implemented circuits include anunder-voltage lockout (UVLO) and a precision reference withaccuracy at the error amplifier input. The UTC UC2842B alsocontain internal circuits which include a pulse width modulation(PWM) comparator providing current-limit control, logic ensuringlatched operation, and a totem-pole output stage designed tosource or sink high-peak current. The output stage is low when itis in off-state condition and suitable for N-channel MOSFETsdriving.The UTC UC2842B also has following advantages: thestart-up current lower than 0.5mA while the oscillator dischargecurrent is specified to 8.3mA (Typ.). In UVLO conditions, theoutput has a maximum saturation voltage of 1.2V when sinking10mA @ V CC = 5V.

特性 Features

Current mode operation:500 kHz Low start-up current value<0.5mA Latching PWM for cycle-by-cycle current limiting Trimmed oscillator discharge current Automatic feed-forward compensation Internally trimmed reference with UVLO High-current totem-pole output UVLO with hysteresis Double-pulse suppression