描述The UC1843 family of control devices provides the necessary features to implement off-line or dc-to-dc fixed frequency current mode control schemes with a minimal external parts count. Internally implemented circuits include under-voltage lockout featuring start up current less than 1 mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, a PWM comparator which also provides current limit control, and a totem pole output stage designed to source or sink high peak current. The output stage, suitable for driving N-Channel MOSFETs, is low in the off state. The under-voltage lockout threshold is 8.4 V and maximum duty cycle range is around 100%.特性–55°C to 125°C Known Good Die Controlled Baseline Optimized For Off-line and DC-to-DC Converters Low Start-Up Current (<1 mA) Automatic Feed Forward Compensation Pulse-by-Pulse Current Limiting Enhanced Load Response Characteristics Under-Voltage Lockout With Hysteresis Double Pulse Suppression High Current Totem Pole Output Internally Trimmed Bandgap Reference 500-kHz Operation Low RO Error Amp