UC1842A-EP General 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.
UC1842A-EP Maximum Ratings
VCC voltage (low impedance source) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 V
VCC voltage (ICC mA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . self limiting
Output current, IO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±1 A
Output energy (capacitive load) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 J
Analog Inputs (pins 3, 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.3 V to 6.3 V
Error Amp Output Sink current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mA
Power Dissipation at TA < +25C (D package) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 W
Package thermal impedance, JA (see Note 1): D (8-pin) package . . . . . . . . . . . . . . . . . . . . 97°C/W
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65oC to 150oC
Lead temperature soldering 1,6 mm (1/16 inch) from case for 10 seconds . . . . . . . . . . . . . . . .. 260 oC
UC1842A-EP Features
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
UC1842A-EP Connection Diagram
Map list: ABCDEFGHIJKLMNOPQRSTUVWXYZ 0123456789All