AS2214

The AS2214 is a full featured, pulse width modulation controller.  Based on an improved AS3842, the AS2214 provides additional features that reduce component count and improve specifications in a wide range of power supply designs.  The added functionality includes AC power and bulk voltage sensing, over-voltage input, as well as the ability to latch off or bounce through different fault conditions.

The PWM function of AS2214 is controlled by the current sense com-parator for normal current mode control and a second comparator for voltage mode soft start.A buffered RAMP signal is available for slope compensation without loading the oscillator.  The output stage is a high current totem pole output that sees only 85 ns delay from the PWM comparator.

The AS2214 requires less than 10A of startup current.The undervoltage lockout (UVLO) thresholds are nominally 13.8V for turn on and 8 V for turn off.  A precision 2.5 V bandgap reference serves as an input for the error amplifier.The oscillator discharge current is trimmed to provide guaran-teed duty cycle clamping.