DESCRIPTIONThe UC3842 is available in an 8-Pin mini-DIP the necessary features to implement off-line, fixed-frequency current-mode control schemes with a minimal external parts count. This technique results in improved line regulation, enhanced load response characteristics, and a simpler, easier to design control loop. Topological advantages include inherent pulse-by-pulse current limiting.
Protection circuitry includes built-in undervoltage lock-out and current limiting. Other features include fully-latched operation, a 1% trimmed bandgap reference, and start-up current less than 1mA. These devices feature a totem-pole output designed to source and sink high peak current from a capacitive load, such as the gate of a power MOSFET. Consistent with N-channel power devices, the output is low in the OFF-state.

FEATURES• Low start-up current (≤1mA)
• Automatic feed-forward compensation
• Pulse-by-pulse current limiting
• Enhanced load response characteristics
• Undervoltage lock-out with hysteresis
• Double pulse suppression
• High current totem-pole output
• Internally-trimmed bandgap reference
• 400kHz operation, guaranteed min

APPLICATIONS• Off-line switched mode power supplies
• DC-to-DC converters UC3842

Manufacturer	Texas Instruments
Product Category	AC DC Converters, Offline Switchers
Series	UC3861
Packaging	Tube Alternate Packaging
Unit-Weight	0.037172 oz
Mounting-Style	Through Hole
Package-Case	16-DIP (0.300", 7.62mm)
Operating-Temperature	0°C ~ 70°C (TA)
Mounting-Type	*
Supplier-Device-Package	16-PDIP
Watt	-
Number-of-Outputs	2 Output
Output-Isolation	Non-Isolated
Internal-Switch-s	Yes
Voltage-Breakdown	-
Topology	Full-Bridge, Half-Bridge, Push-Pull
Voltage-Start-Up	16.5V
Voltage-Supply-Vcc-Vdd	10.5 V ~ 22 V
Duty-Cycle	-
Frequency-Switching	10kHz ~ 1MHz
Fault-Protection	-
Control-Features	Soft Start
Maximum Operating Temperature	+ 70 C
Operating temperature range	0 C
Output-Current	500 mA
Switching-Frequency	450 kHz
Fall-Time	25 ns
Rise-Time	25 ns
Package-Case	PDIP-16
Duty-Cycle-Max	50 %