MAX8568A_05 Datasheet, PDF (1/17 Pages) Maxim Integrated Products – Complete Backup-Management ICs for Lithium and NiMH Batteries

19-3450; Rev 1; 5/05
EVAALVUAAILTAIOBNLEKIT
Complete Backup-Management ICs
for Lithium and NiMH Batteries
General Description
The MAX8568A/MAX8568B backup-battery-management
ICs are complete charging and backup switchover con-
trol solutions for PDAs, Smart Phones, and other smart
portable devices. They charge both NiMH and
rechargeable lithium battery types and feature pro-
grammable 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 on-
chip 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 on-
chip synchronous-rectified, low-quiescent-current boost
converter. Additionally, a low-quiescent-current LDO gen-
erates 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.
Applications
PDAs and PDA Phones
Smart Phones
DSCs and DVCs
Palmtops and Wireless Handhelds
Internet Appliances and Web-Books
Pin Configuration
TOP VIEW
12 11 10 9
GND 13
STRTV 14
TERMV 15
REF 16
MAX8568A
MAX8568B
8 OD2
7 OD1
6 LDO
5 BKSU
1
2
3
4
Features
♦ Automatically Manage All Backup Switchover
Functions
♦ Charge Both NiMH and Rechargeable Lithium
Backup Batteries
♦ On-Chip Battery Boost Converter for 1-Cell NiMH
♦ Two Backup Output Voltages
♦ Programmable Charge Current
♦ Programmable Charge Voltage Limit
♦ Low 17µA Operating Current in Backup Mode
♦ Eliminate Many Discrete Components
♦ Tiny 3mm x 3mm Thin QFN Package
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
MAX8568AETE
-40°C to +85°C
16 Thin QFN
3mm x 3mm
(T1633-4)
MAX8568BETE
-40°C to +85°C
16 Thin QFN
3mm x 3mm
(T1633-4)
TOP
MARK
ACK
ACL
Typical Operating Circuit
MAIN BATTERY
2.8V TO 5.5V
BACKUP
BATTERY
IN
REF
BK _MAX8568A
MAX8568B
TERMV
I/O OUT
3.3V, 50mA
LX
STRTV
BKSU
IN
I/O IN
PGND
GND
MEM OUT
1.8V OR 2.5V, 10mA
MEM IN
BKV
INOK
OD1
CHGI
LDO
THIN QFN
NI
OD2
NI/LI
LI
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.