Accuracy-Enhanced Ramp-Generation Design for D-CAP3 Modulation
D-CAP and D-CAP2 control schemes have been widely used in TI Switched-Mode DC-DC converters due to their fast transient response and no off-chip compensation. Offset generated by current sense ramp adds an error to VFB and Vout and hence reduces DC accuracy. This paper introduces a new D-CAP3 control scheme which greatly improves DC accuracy of the converter while maintaining the same fast transient response as D-CAP/D-CAP2. Meanwhile, compact silicon implementation makes the new DCAP3 control extremely low cost. D-CAP3 control has been implemented in many TI products such as TPS53912, TPS53913, TPS53915, TPS53513, TPS53515, TPS548A20, TPS56C216, and TPS548D22 and greatly improved performance of these products.