Controlled Baseline
− One Assembly/Test Site, One Fabrication
Site
Extended Temperature Performance of
−55°C to 125°C
Enhanced Diminishing Manufacturing
Sources (DMS) Support
Enhanced Product Change Notification
Qualification Pedigree†
Optimized for Off-line and DC-to-DC
Converters
Low Start Up Current (<0.5 mA)
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
500 kHz Operation
Low RO Error Amp

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 0.5 mA. Oscillator discharge is
trimmed to 8.3 mA. During under voltage lockout, the output stage can sink at least 10 mA at less than 1.2 V
for VCC over 5 V.
The difference between members of this family are shown in the table below.