DESCRIPTION

· The MIC38HC4x family are fixed frequency current-mode PWM controllers with 1A drive current capability.
· Pin-compatible with 384x bipolar devices, featuring high output drive and fast rise and fall times.
· Undervoltage lockout circuitry varies by version, with operating voltages up to 20V.
· Reduced start-up and operating currents compared to bipolar UC384x devices.
· Available in 14-pin plastic DIP and SOIC packages, with 8-pin devices offering compact size.

FEATURES

· Fast 20ns output rise and 15ns output fall times.
· Operates in a temperature range of -40°C to +85°C.
· High-performance, low-power BiCMOS Process.
· Ultralow start-up current (50 µA typical) and low operating current (4mA typical).
· High output drive with 1A peak current, CMOS outputs with rail-to-rail swing.
· Current-mode operation up to 500kHz, trimmed 5V bandgap reference.
· Pin-for-pin compatible with UC3842/3843/3844/3845(A), trimmed oscillator discharge current.
· UVLO with hysteresis and low cross-conduction currents.

APPLICATIONS

· Current-mode, off-line, switched-mode power supplies.
· Current-mode, dc-to-dc converters.
· Step-down "buck" regulators and step-up "boost" regulators.
· Flyback, isolated regulators and forward converters.
· Synchronous FET converters.