This document describes the LTC4215-1 chip, which integrates three GPIO lines and an ADC to monitor the board voltage and current. It can provide switch control and status information through GPIO for power management.
The document describes an application note titled 'An Easy Way to Add Auxiliary Control Functions to Hot Swap Cards' (Design Note 421) by Mark Thoren. It focuses on upgrading standard Hot Swap controllers like the LTC4210-1 or LTC4215-1 with additional general-purpose I/O (GPIO) lines and an accurate ADC.
The text details how these GPIO pins can be used for various 'power gateway' functions, including sequencing power supplies, monitoring pushbuttons, controlling onboard regulators in mixed-signal circuits, and issuing microprocessor resets. It includes circuit examples showing the control of LEDs and status indicators.
It integrates three general purpose I/O lines and an accurate ADC into the Hot Swap controller to provide quantitative information on board voltage and current.
They can control onboard regulators to ensure analog circuitry is powered up before digital signals are enabled in mixed signal circuits.