Current Mode PWM Controller - UC3843A

UC3843A (ACTIVE)

Current Mode PWM Controller

 

Description

The UCx84xA family of control ICs 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 VCC over 5 V.

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

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Parametrics Compare all products in PWM and Resonant Controller

 
Topology
Control Method
Vin (Min) (V)
Vin (Max) (V)
Frequency (Max) (kHz)
UVLO Thresholds On/Off (V)
Duty Cycle (Max) (%)
Gate Drive (Typ) (A)
Special Features
Rating
Operating Temperature Range (C)
Pin/Package
UC3843A UC1843A UC2843A
Boost
Buck
Flyback
Forward   
Boost
Flyback
Forward   
Boost
Buck
Buck-Boost
Flyback
Forward   
Current    Current    Peak Current Mode   
7.6    7.6    8.4   
30    30    400   
500    500    500   
8.4/7.6    8.4/7.6    8.4/7.6   
100    100    100   
1    1    1   
Error Amplifier    Error Amplifier
Multi-topology   
Error Amplifier
Multi-topology   
Catalog    Military    Catalog   
0 to 70    -55 to 125    -40 to 85   
14SOIC
8PDIP
8SOIC   
8CDIP
20LCCC   
14SOIC
8PDIP
20PLCC
8SOIC   

Other qualified versions of UC3843A

Version Part Number Definition
Military UC1843A QML certified for Military and Defense Applications
Enhanced Product UC1843A-EP Supports Defense, Aerospace and Medical Applications
Space UC1843A-SP Radiation tolerant, ceramic packaging and qualified for use in Space-based application

Featured tools and software

WEBENCH® Designer UC3843A

AC Frequency  60 Hz  50 Hz
  Min   Max Range
VinRMS  V 15.0 to 480.0V
Vout  V 3.3 to 50V
Iout  A ≤ 20A
Ambient Temp  °C 0 to 70°C