The MAX8568A/MAX8568B backup-battery-management
ICs are complete charging and backup switchover control
solutions for PDAs, Smart Phones, and other smart
portable devices. They charge both NiMH and
rechargeable lithium battery types and feature programmable
charge current and termination voltage.
Separate optimized charge algorithms for both lithium
and NiMH cells are included on-chip.
The MAX8568A/MAX8568B also manage backup
switchover from a primary power source. An accurate onchip
voltage detector monitors the main supply and
backs up two system supplies (typically I/O and memory)
when main power falls. On-chip drivers switch external
MOSFETs to disconnect the main supply from the system
loads so the backup source is not drained.
Low-voltage backup cells can be stepped up by an onchip
synchronous-rectified, low-quiescent-current boost
converter. Additionally, a low-quiescent-current LDO generates
a second backup voltage. The MAX8568A LDO is
preset to 2.5V while the MAX8568B LDO is preset to 1.8V.
Both devices are supplied in 16-pin 3mm x 3mm thin
QFN packages rated for -40°C to +85°C operation.