UCC1580-2

Features:

·Provides Auxiliary Switch Activation Complementary to Main Power Switch Drive
·Programmable deadtime (Turn-on Delay) Between Activation of Each Switch
·Voltage Mode Control with Feedforward Operation
·Programmable Limits for Both Transformer Volt- Second Product and PWM Duty Cycle
·High Current Gate Driver for Both Main and Auxiliary Outputs
·Multiple Protection Features with Latched Shutdown and Soft Restart
·Low Supply Current (100
A Startup, 1.5 mA Operation)


Pinout




Specifications

VDD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16V
I_VDD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 25mA
LINE, RAMP . . . . . . . . . . . . . . . . . . . . . .  . . . . 0.3V to VDD + 1V
I_LINE, I_RAMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA
DELAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3V
I_DELAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA
I_OUT1 (tpw < 1 s and Duty Cycle < 10%) . . . . . . . 0.6A to 1.2A
I_OUT2 (tpw < 1 s and Duty Cycle < 10%) . . . . . . . 0.4A to 0.4A
I_CLK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  . . 100mA to 100mA
OSC1, OSC2, SS, SHTDWN, EAIN . .  . .  . . .  0.3V to REF + 0.3V
I_EAOUT. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  . . . . . 5mA to 5mA
I_REF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30mA
PGND. . . . . . . . . . . . . . . . . . . . . . . . . . . . .  . . . . . . 0.2V to 0.2V
Storage Temperature . . . . . . . . . . . . . . . . .  . . . 65 to +150
Junction Temperature. . . . . . . . . . . . . . . .  . . . . 55 to +150
Lead Temperature (Soldering, 10 sec.) . . . . . . . . . . . . . +300

All voltages are with respect to ground unless otherwise stated. Currents are positive into, negative out of the specified terminal. Consult Packaging Section of Databook for thermal limitations and considerations of packages.


Description

The UCC1580-2 PWM controllers is designed to implement a variety of active clamp/reset and synchronous rectifier switching converter topologies. While containing all the necessary functions for fixed frequency, high performance pulse width modulation, the additional feature of this design is the inclusion of an auxiliary switch driver which complements the main power switch, and with a programmable deadtime or delay between each transition. The active clamp/reset technique of UCC1580-2 allows operation of single ended converters beyond 50% duty cycle while reducing voltage stresses on the switches, and allows a greater flux swing for the power transformer. This approach also allows a reduction in switching losses by recovering energy stored in parasitic elements such as leakage inductance and switch capacitance.

The oscillator UCC1580-2 is programmed with two resistors and a capacitor to set switching frequency and maximum duty cycle. A separate synchronized ramp provides a voltage feedforward pulse width modulation and a programmed maximum volt-second limit. The generated clock of UCC1580-2 from the oscillator contains both frequency and maximum duty cycle information.