UC2844BD1013TR High Performance Current Mode PWM Controller with 500 kHz Switching Frequency, 1 A Output Current, and 50% Max Duty Cycle

• TRIMMED OSCILLATOR FOR PRECISE FREQUENCY CONTROL.
• OSCILLATOR FREQUENCY GUARANTEED AT 250kHz.
• CURRENT MODE OPERATION TO 500kHz.
• AUTOMATIC FEED FORWARD COMPENSATION.
• LATCHING PWM FOR CYCLE-BY-CYCLE CURRENT LIMITING.
• INTERNALLY TRIMMED REFERENCE WITH UNDERVOLTAGE LOCKOUT.
• HIGH CURRENT TOTEM POLE OUTPUT.
• UNDERVOLTAGE LOCKOUT WITH HYSTERESIS.
• LOW START-UP AND OPERATING CURRENT

The UC384xB family of control ICs 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 a trimmed oscillator for precise DUTY CYCLE CONTROL under voltage lockout featuring start-up current less than 0.5mA, a precision reference trimmed for accuracy at the erroramp 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 offstate.

Differences between members of this family are the under-voltage lockout thresholds and maximum duty cycle ranges. The UC3842B and UC3844B have UVLO thresholds of 16V (on) and 10V (off), ideally suited off-line applications The corresponding thresholds for the UC3843B and UC3845B are 8.5 V and 7.9V. The UC3842B and UC3843B can operate to dutycycles approaching 100%. A range of the zero to <50 % is obtained by the UC3844B and UC3845B by the addition of an internal toggle flip flop which blanks the output off every other clock cycle.

Standard export packaging available. Customers can choose from cartons, wooden cases, and wooden pallets according to their requirements.

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Small batches typically ship within 7-15 days, while large batch orders may require approximately 30 days depending on order quantity and season.

Factory pricing with 30% deposit and 70% balance payment via T/T before shipment.