PWM Controllers Eye Tasks In Sub-150W Converters

Designed for feed forward operation in sub-150W dc/dc power converters, these voltage-mode, pulse-width modulated (PWM) controllers include two devices: the CS51221 is designed for applications that require a full set of control and protection features, while CS51227 is a basic device targeted at more cost-sensitive applications. On-chip capabilities reportedly reduce external component count, board area requirements, and overall power converter cost. The 16-lead CS51221 provides programmable pulse-by-pulse overcurrent protection, overvoltage protection with programmable hysteresis, undervoltage lockout, accurate programmable duty cycle limit, leading edge current sense blanking, and bi-directional synchronization. The 8-lead CS51227 offers fewer options, but still contains many of the control capabilities required for supply operation.