UCC28083, UCC28084, UCC28085, UCC28086 UCC38083, UCC38084, UCC38085, UCC38086
SLUS488E − SEPTEMBER 2002 − REVISED JULY ...
UCC28083, UCC28084, UCC28085, UCC28086 UCC38083, UCC38084, UCC38085, UCC38086
SLUS488E − SEPTEMBER 2002 − REVISED JULY 2009
8ĆPIN CURRENT MODE PUSHĆPULL PWM CONTROLLERS WITH PROGRAMMABLE SLOPE COMPENSATION
FEATURES
D Programmable Slope Compensation D Internal Soft-Start on the UCC38083/4 D Cycle-by-Cycle Current Limiting D Low Start-Up Current of 120 µA and 1.5 mA
Typical Run Current
D Single External Component Oscillator
Programmable from 50 kHz to 1 MHz
D High-Current Totem-Pole Dual Output Stage
Drives Push-Pull Configuration with 1-A Sink and 0.5-A Source Capability
D Current Sense Discharge Transistor to
Improve Dynamic Response
D Internally Trimmed Bandgap Reference D Under
voltage Lockout with Hysteresis
BASIC APPLICATION
V IN
VDD UCC3808x
CTRL OUTA
RT OUTB
ISET
CS
RT R SET
GND
POWER TRANSFORMER
RF CF RS
FEEDBACK
APPLICATIONS
D High-Efficiency Switch-Mode Power Supplies D Telecom dc-to-dc Converters D Point-of-Load or Point-of-Use Power Modules D Low-Cost Push-Pull and Half-Bridge
Applications
DESCRIPTION
The UCC38083/4/5/6 is a family of Bi
CMOS pulse width modulation (PWM) controllers for dc-to-dc or off-line fixed-frequency current-mode switching power supplies. The dual output stages are configured for the push-pull topology. Both outputs switch at half the oscillator frequency using a toggle flip-flop. The dead time between the two outputs is typically 110 ns, limiting each output’s duty cycle to less than 50%.
The new UCC3808x family is based on the U...