HIGH PERFORMANCE CURRENT MODE PWM CONTROLLERS
DESCRIPTION
The UTC UC3844/3845 are high performance fixed frequency
current mode controllers that specifically designed for Off-Line and
DC to DC converter applications with minimal external parts count.
The differences between UC3844 and UC3845 are the maximum
duty cycle ranges and under-voltage lockout thresholds. The
UC3844 ideally suited to off-line applications with UVLO thresholds
of 16V(ON) and 10V(OFF), and UC3845 has UVLO thresholds of
8.5V(ON) and 7.6V(OFF) for lower voltage applications.
FEATURES
* Operation output switching frequency up to 500 kHz
* Output deadtime adjustable from 50% to 70%
* Automatic feed forward compensation
* Latching PWM for cycle-by-cycle current limiting
* High current totem pole output
* Internally trimmed reference with under voltage lockout
* UVLO with hysteresis
* Low startup and operating current |
