Current Mode PWM Controller - UC3843A

UC3843A (ACTIVE)

Current Mode PWM Controller

 

Description

The UC1842A/3A/4A/5A family of control ICs is a pin for pin compatible improved version of the UC3842/3/4/5 family. Providing the necessary features to control current mode switched mode power supplies, this family has the following improved features. Start up current is guaranteed to be less than 0.5mA. Oscillator discharge is trimmed to 8.3mA. During under voltage lockout, the output stage can sink at least 10mA at less than 1.2V for VCC over 5V.

Features

  • Optimized for Off-line and DC to DC Converters
  • Low Start Up Current (<0.5mA)
  • Trimmed Oscillator Discharge Current
  • 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
  • 500kHz Operation
  • Low RO Error Amp

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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

WEBENCH® Designer UC3843A

 AC  DC  
AC Frequency  60 Hz  50 Hz
Use Isolated Output?
  Min   Max Range
VinRMS  V 20.00 to 300.00V
Vout  V 3.3 to 50.0V
Iout  A ≤ 20.0A
Ambient Temp  °C 0 to 70°C

Parametrics Compare all products in Offline and Isolated DC/DC Controller and Converter

 
Control Method
Vin (Min) (V)
Vin (Max) (V)
Topology
Duty Cycle (Max) (%)
Frequency (Max) (kHz)
UVLO Thresholds On/Off (V)
Special Features
Rating
Operating Temperature Range (C)
Package Group
Package Size (mm2=WxL)
UC3843A UC1843A UC2843A
Current     Current     Current    
7.6     7.6     7.6    
30     30     30    
Boost
Buck
Flyback
Forward    
Boost
Flyback
Forward    
Boost
Flyback
Forward    
100     100     100    
500     500     500    
8.4/7.6     8.4/7.6     8.4/7.6    
Error Amplifier     Error Amplifier     Error Amplifier    
Military     Military     Catalog    
0 to 70     -55 to 125     -40 to 85    
PDIP
SOIC
WAFERSALE    
CDIP
LCCC    
PDIP
PLCC
SOIC    
8SOIC: 29 mm2: 6 x 4.9
14SOIC: 52 mm2: 6 x 8.65    
8CDIP: 64 mm2: 6.67 x 9.6
20LCCC: 79 mm2: 8.89 x 8.89    
8SOIC: 29 mm2: 6 x 4.9
14SOIC: 52 mm2: 6 x 8.65
20PLCC: 98 mm2: 9.9 x 9.9