SG3525AP013TR

The SG3525A series of pulse width modulator integrated circuits are designed to offer improved performance and lowered external parts count when
used in designing all types of switching power supplies. The on-chip + 5.1 V reference is trimmed to ±
1 % and the input common-mode range of the error
amplifier includes the reference voltage eliminating
external resistors. A sync input to the oscillator allows multiple units to be slaved or a single unit to be
synchronized to an external system clock. A single
resistor between the CT and the discharge terminals
provide a wide range of dead time ad- justment.
These devices also feature built-in soft-start circuitry
with only an external timing capacitor required. A
shutdown terminal controls both the soft-start circuity and the output stages, providing instantaneous
turn off through the PWM latch with pulsed shutdown, as well as soft-start recycle with longer shutdown commands. These functions are also controlled by an undervoltage lockout which keeps the outputs off and the soft-start capacitor discharged for
sub-normal input voltages. This lockout circuitry includes approximately 500 mV of hysteresis for jitterfree operation. Another feature of these PWM circuits is a latch following the comparator. Once a
PWM pulses has been terminated for any reason,
the outputs will remain off for the duration of the period. The latch is reset with each clock pulse. The
output stages are totem-pole designs capable of
sourcing or sinking in excess of 200 mA. The
SG3525A output stage features NOR logic, giving a
LOW output for an OFF state.