Self-stabilizing, integrated, hysteretic boost DC-DC converter

In portable, battery-powered applications, integration of switching DC-DC converters is crucial to reap maximum benefits in size, cost, and design ease. The frequency compensation circuit, whose design varies with off-chip, passive filter (L-C) components, forms a critical hurdle to obtaining a fully integrated solution. Surveying state-of-the-art control techniques in literature, hysteretic control in buck converters, which in a single loop, controls inductor current ripple indirectly while regulating the output voltage, is observed to be the simplest, fastest, and needing no compensation circuit, thus being best suitable for integration. However, the technique is not readily applied to boost converters. This paper proposes a novel technique to harness voltage-mode hysteretic control in boost converters by controlling inductor current and output voltage through separate loops. The proposed circuit designed for V_IN=1.2 V (nom), V_out=3.3 V ±5%, I_out=0.1 to 1 A shows excellent voltage regulation and transient response (±150 mV), without the use of any compensation circuit.