DC-DC Controller UC3843 SMD IC

The UCx84xA family of control devices is a pin-for-pin compatible improved version of the UCx84x family. Providing the necessary features to control current-mode or switched-mode power supplies, this family of devices has many improved features: startup current is less than 0.5 mA, oscillator discharge is trimmed to 8.3 mA, and during UVLO, the output stage can sink at least 10 mA at less than 1.2 V for V_CC over 5 V.

Parameters

• Topology : Boost, Buck, Flyback, Forward
• Duty cycle (Max) (%) : 100
• Vin (Max) (V) : 28
• UVLO thresholds on/off (V) : 8.4/7.6
• Features : Adjustable Switching Frequency, Current Limiting, Dead Time Control, Error Amplifier, Multi-topology
• Operating temperature range (C) : 0 to 70
• Switching frequency (Max) (kHz) : 500
• Rating : Catalog
• Gate drive (Typ) (A) : 1

Features:

• Optimized for Off-Line and DC-DC Converters
• Low Start-Up Current (< 0.5 mA)
• Trimmed Oscillator Discharge Current
• Automatic Feedforward Compensation
• Pulse-by-Pulse Current Limiting
• Enhanced Load Response Characteristics
• Undervoltage Lockout With Hysteresis
• Double Pulse Suppression
• High-Current Totem Pole Output
• Internally-Trimmed Bandgap Reference
• Up to 500-kHz Operation

Applications

• Switch Mode Power Supplies (SMPS)
• DC-DC Converters
• Power Modules
• Industrial PSU
• Battery Operated PSU

Datasheet