by Timothy Hegarty, Texas Instruments, Phoenix, Ariz., How2Power Today, Feb 14 2025
Focus:
This article examines a constant-current, constant-voltage (CC-CV) dual-loop architecture
for a dc-dc regulator. The author outlines existing designs for the CC circuit that work
as an add-on to a conventional dc-dc regulator. He then details a CC-CV integrated circuit
(IC) approach with low external component count, reduced cost, accurate current-setpoint
performance and improved transient response. The IC implementation is unique in that it
selects the minimum of the currents from the transconductance error amplifiers in the CV
and CC loops. This error current then flows in a shared compensation component network,
the resultant compensation voltage becoming the reference command of the inner current
loop of the current-mode architecture. Simulation results of the CV and CC loops, and a
laboratory testbed based on a commercially available CC-CV synchronous buck controller
(the LM5190-Q1) illustrate the performance characteristics of the dual-loop architecture.
What you’ll learn:
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