MAX38888EVKIT#: Super Capacitor Backup Regulator

Summary

The MAX38888 is a storage capacitor or capacitor bank backup regulator designed to efficiently transfer power between a storage element and a system supply rail in reversible buck and boost operations using the same inductor.

When the main supply is present and above the minimum system supply voltage, the regulator operates in buck mode and charges the storage element at up to 500mA peak inductor current. Once the storage element is charged, the circuit draws only 2.5µA of current while it maintains the super capacitor or other storage element in its ready state. When the main supply is removed, the regulator operates in boost mode and prevents the system from dropping below the minimum operating voltage, discharging the storage element at up to 2.5A peak inductor current.

The MAX38888 is externally programmable for minimum and maximum voltage of the storage element, such as super capacitor, minimum system voltage, and maximum charge and discharge currents. The internal DC/DC converter requires only a 1µH inductor.

Benefits and Features

2.5V to 5V System Output Voltage
0.8V to 4.5V Cap Voltage Range
Up to 2.5A Peak Inductor Discharge Current
Programmable Voltage and Current Thresholds
±2% Threshold Accuracy
Up to 95% Efficiency, Charge or Discharge
2.5µA Ready Quiescent Current
3mm x 3mm x 0.75mm TDFN Package

Specifications

Manufacturer	Analog Devices Inc./Maxim Integrated
Category	Power Management
Sub-Category	Capacitor Chargers
Eval Board Part Number	MAX38888EVKIT#-ND
Eval Board Supplier	Analog Devices Inc./Maxim Integrated
Eval Board	Normally In Stock
Capacitor Type	Super Capacitor
Function	Backup Power Controller
Number of Capacitors	1
Voltage In	2.5 ~ 5 V
Voltage Out (Max)	4.5 V
Charge Current (Max)	500 mA
Topology	Bidirectional Buck-Boost
Features	±2% Output Accuracy Adjustable Output Current Adjustable Output Voltage
Quiescent Current	2.5 µA
Component Count + Extras	18 + 12
Main I.C. Base Part	MAX38888
Design Author	Maxim Integrated Products
Date Created By Author	2018-10
Date Added To Library	2018-11