TIDA-00122(#2): 230VAC @ 200VA, 10.5 ~ 14.5V in

This document presents low-cost, small size, robust 200-VA DC to AC inverter based on TI’s MSP430G2553 and UCD8220-digitally managed push-pull controller. In this design, UCD8220 is used for a boost stage to get 250-V DC from a 12-V battery. The MSP430G2553 acts as a host controller and provides a 100-kHz clock to UCD8220 and drives for output DC-AC bridge. UCD8220 internally generates push-pull drives for MOSFETs. Current limit is set through a simple resistor divider at the ISET pin. In the case of an overcurrent limit, the UCD8220 sets the current flag (CF) pin high and the device is turned off by the host controller if the current limit exceeds a certain number of cycles. Low-Rdson MOSFETs help keep conduction losses within limit. This inverter has a peak efficiency of 90%. This design has natural cooling and does not require a fan for cooling. The features of this design include ignition sensing, engine-on sensing, reverse battery protection and overcurrent latch. Target applications of this design are for car inverters and small-segment inverters for commercial applications.