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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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